Filed Pursuant to Rule 424(b)(5)

Registration No. 333-235686

The information in this preliminary prospectus supplement is not complete and may be changed. A registration statement relating to these securities has been filed with the Securities and Exchange Commission and is effective. This preliminary prospectus supplement and the accompanying prospectus are not an offer to sell these securities and they are not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted.

SUBJECT TO COMPLETION, DATED FEBRUARY 2, 2021

Preliminary Prospectus Supplement

(to Prospectus dated April 9, 2020)

Shares of Common Stock

Pre-Funded Warrants to Purchase Shares of Common Stock

We are offering shares of our common stock.

We are also offering to certain purchasers whose purchase of shares of common stock in this offering would otherwise result in the purchaser, together with its affiliates and certain related parties, beneficially owning more than 4.99% (or, at the election of the purchaser, 9.99%) of our outstanding common stock immediately following the consummation of this offering, the opportunity to purchase, if any such purchaser so chooses, pre-funded warrants, in lieu of shares of common stock that would otherwise result in such purchaser’s beneficial ownership exceeding 4.99% (or, at the election of the purchaser, 9.99%) of our outstanding common stock. Each pre-funded warrant will be exercisable for one share of our common stock. The purchase price of each pre-funded warrant will be equal to the price at which a share of common stock is sold to the public in this offering, minus $0.001, and the exercise price of each pre-funded warrant will be $0.001 per share. The pre-funded warrants will be immediately exercisable and may be exercised at any time until all of the pre-funded warrants are exercised in full. This offering also relates to the shares of common stock issuable upon exercise of any pre-funded warrants sold in this offering. For each pre-funded warrant we sell, the number of shares of common stock we are offering will be decreased on a one-for-one basis.

Our common stock is listed on The Nasdaq Capital Market, or Nasdaq, under the symbol “MBRX.” On February 2, 2021, the last reported sale price of our common stock on Nasdaq was $6.39 per share. There is no established public trading market for the pre-funded warrants, and we do not expect a market to develop. In addition, we do not intend to apply for a listing of the pre-funded warrants on any national securities exchange. Without an active trading market, the liquidity of the pre-funded warrants will be limited.

We are an “emerging growth company” under the federal securities laws and are subject to reduced public company reporting requirements for this prospectus and future filings.

Investing in our securities involves a high degree of risk. See “Risk Factors” beginning on page S-6 of this prospectus supplement and the risk factors in the documents incorporated by reference into this prospectus supplement and the accompanying prospectus.

	Per Share	Per Pre-Funded Warrant	Total
Price to public	$	$	$
Underwriting discount(1)
Proceeds to us (before expenses)

________________________

(1) See “Underwriting” beginning on page S-12 for additional information regarding the compensation payable to the underwriters.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus supplement or the accompanying prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

We have granted a 30-day option to the underwriters to purchase up to additional shares of common stock solely to cover overallotments, if any.

Delivery of the shares of our common stock and any pre-funded warrants is expected to be made on or about , 2021.

Sole Book-Running Manager

Oppenheimer & Co.

The date of this prospectus supplement is            , 2021.

Table of Contents

	Page
About This Prospectus Supplement	S-1
Prospectus Supplement Summary	S-2
Risk Factors	S-6
Cautionary Note Regarding Forward-Looking Statements	S-8
Use of Proceeds	S-9
Dividend Policy	S-9
Dilution	S-10
Description of Securities We Are Offering	S-11
Underwriting	S-12
Legal Matters	S-19
Experts	S-19
Incorporation by Reference	S-19
Where You Can Find More Information	S-20

Prospectus

About This Prospectus	1
Where You Can Find More Information	1
Incorporation By Reference	1
About MBI	2
Risk Factors	3
Forward-Looking Statements	3
Use Of Proceeds	3
Description Of Common Stock	4
Description Of Preferred Stock	5
Description Of Debt Securities	6
Description Of The Warrants	14
Description Of The Stock Purchase Contracts And Stock Purchase Units	16
Plan Of Distribution	16
Legal Matters	19
Experts	19

About This Prospectus Supplement

This prospectus supplement and the accompanying prospectus are part of a registration statement that we filed with the Securities and Exchange Commission (the “SEC”) utilizing a “shelf” registration process. Each time we conduct an offering to sell securities under the accompanying prospectus we will provide a prospectus supplement that will contain specific information about the terms of that offering, including the price, the amount of securities being offered and the plan of distribution. The shelf registration statement was initially filed with the SEC on December 23, 2019, and was declared effective by the SEC on April 9, 2020. This prospectus supplement describes the specific details regarding this offering and may add, update or change information contained in the accompanying prospectus. The accompanying prospectus provides general information about us and our securities, some of which, such as the section entitled “Plan of Distribution,” may not apply to this offering. This prospectus supplement and the accompanying prospectus are an offer to sell only the securities offered hereby, but only under circumstances and in jurisdictions where it is lawful to do so. We are not making offers to sell or solicitations to buy our common stock in any jurisdiction in which an offer or solicitation is not authorized or in which the person making that offer or solicitation is not qualified to do so or to anyone to whom it is unlawful to make an offer or solicitation.

If information in this prospectus supplement is inconsistent with the accompanying prospectus or the information incorporated by reference with an earlier date, you should rely on this prospectus supplement. This prospectus supplement, together with the base prospectus, the documents incorporated by reference into this prospectus supplement and the accompanying prospectus and any free writing prospectus we have authorized for use in connection with this offering include all material information relating to this offering. We have not, and the underwriters have not, authorized anyone to provide you with different or additional information and you must not rely on any unauthorized information or representations. You should assume that the information appearing in this prospectus supplement, the accompanying prospectus, the documents incorporated by reference in this prospectus supplement and the accompanying prospectus and any free writing prospectus we have authorized for use in connection with this offering is accurate only as of the respective dates of those documents. Our business, financial condition, results of operations and prospects may have changed since those dates. You should carefully read this prospectus supplement, the accompanying prospectus and the information and documents incorporated herein by reference herein and therein, as well as any free writing prospectus we have authorized for use in connection with this offering, before making an investment decision. See “Incorporation by Reference” and “Where You Can Find More Information” in this prospectus supplement and in the accompanying prospectus.

No action is being taken in any jurisdiction outside the United States to permit a public offering of these securities or possession or distribution of this prospectus supplement or the accompanying prospectus in that jurisdiction. Persons who come into possession of this prospectus supplement and the accompanying prospectus in jurisdictions outside the United States are required to inform themselves about and to observe any restrictions as to this offering and the distribution of this prospectus supplement and the accompanying prospectus applicable to that jurisdiction.

This prospectus supplement and the accompanying prospectus contain summaries of certain provisions contained in some of the documents described herein which are summaries only and are not intended to be complete. Reference is made to the actual documents for complete information. All of the summaries are qualified in their entirety by the full text of the actual documents, some of which have been filed or will be filed and incorporated by reference herein. See “Where You Can Find More Information” in this prospectus supplement. We further note that the representations, warranties and covenants made by us in any agreement that is filed as an exhibit to any document that is incorporated by reference into this prospectus supplement or the accompanying prospectus were made solely for the benefit of the parties to such agreement, including, in some cases, for the purpose of allocating risk among the parties to such agreements, and should not be deemed to be a representation, warranty or covenant to you. Moreover, such representations, warranties or covenants were accurate only as of the date when made. Accordingly, such representations, warranties and covenants should not be relied on as accurately representing the current state of our affairs.

This prospectus supplement and the accompanying prospectus contain and incorporate by reference certain market data and industry statistics and forecasts that are based on Company-sponsored studies, independent industry publications and other publicly available information. Although we believe these sources are reliable, estimates as they relate to projections involve numerous assumptions, are subject to risks and uncertainties, and are subject to change based on various factors, including those discussed under “Risk Factors” in this prospectus supplement and the accompanying prospectus and under similar headings in the documents incorporated by reference herein and therein. Accordingly, investors should not place undue reliance on this information.

Unless otherwise stated or the context requires otherwise, all references in this prospectus supplement to the “Company,” “we,” “us,” “our”, “MBI” and “Moleculin” refer to Moleculin Biotech, Inc., a Delaware corporation, and its wholly-owned subsidiaries.

S-1

Prospectus Supplement Summary

This summary highlights information contained elsewhere in this prospectus supplement, the accompanying prospectus and the documents incorporated by reference herein and therein. This summary does not contain all of the information that you should consider before deciding to invest in our securities. You should read this entire prospectus supplement and the accompanying prospectus carefully, including the section entitled “Risk Factors” beginning on page S-6 and our consolidated financial statements and the related notes and the other information incorporated by reference into this prospectus supplement and the accompanying prospectus, before making an investment decision.

Our Company

We are a clinical stage pharmaceutical company focused on the treatment of highly resistant cancers and viruses. We have three core technologies, all of which are based on discoveries made at M.D. Anderson Cancer Center (MD Anderson). We have three drug candidates, representing two of the three core technologies, that have shown human activity in early-stage clinical trials.

As of the end of 2020, those three drug candidates accounted for five clinical trials in the US and Europe. Two of those trials are ongoing externally funded studies of WP1066 in brain tumors. Two internally funded Phase 1 clinical trials, Annamycin in acute myeloid leukemia (AML), and WP1220 in cutaneous T-cell lymphoma (CTCL), were successfully concluded, pending follow-up observations. An additional Phase 1/2 clinical trial of Annamycin in AML is also internally funded and is currently ongoing. In 2021, we anticipate the initiation of five new clinical trials in addition to the three trials continuing from 2020. In late 2020, we received U.S. Food and Drug Administration (FDA) clearance to proceed with an additional Phase 1b/2 clinical trial of Annamycin for the treatment of sarcoma lung metastases and we are preparing to begin this trial in the U.S. We also plan to seek approval to begin a Phase 1/2 clinical trial of Annamycin in combination with Ara-C for the treatment of AML in Europe. These two new trials will be internally funded. We expect a second Phase 1b/2 clinical trial of Annamycin in sarcoma lung metastases to be primarily investigator-funded in Europe and we plan to seek a collaborative partner to support a Phase 2 clinical study of WP1220 in CTCL. Finally, we are working to initiate a Phase 1 clinical trial of WP1122 in COVID-19, the location of which has yet to be determined. This trial may be internally or externally funded, depending on the timing and nature of the study.

By “internally funded” we mean that the primary costs of the preclinical activity and clinical trials are performed and funded by us. “Externally funded” drug candidates include those for which preclinical work is performed by external collaborators and for which clinical trials are investigator-initiated. In such cases any grant funds that support such preclinical work or clinical trials and most of the associated expenses do not flow through our financial statements. We do provide drug product and other minor supporting activities for externally funded preclinical activities and clinical trials.

We recently announced collaborations with third parties to assist us in developing potential treatments for certain viral diseases, including potentially COVID-19. The preclinical work to evaluate the potential of molecules within the WP1122 portfolio of antimetabolites (which include molecules intended to inhibit glycolysis and alter glycosylation) against viruses is mostly similar to the preclinical work we originally planned to accomplish in 2020 to develop WP1122 for cancer indications. Accordingly, we believe the preclinical work under way for WP1122 will support an Investigational New Drug (IND) application or its equivalent for either cancer-related or virus-related clinical trials (or both) in the first half of 2021. The timing of any such clinical trial is subject to the limited access we have to validated in vivo efficacy testing or our ability to obtain approval from a regulatory body to proceed without in vivo efficacy studies. Additionally, we primarily rely on such collaborations for testing other molecules in the WP1122 portfolio against other hard to treat viruses.

Based on our positive pre-clinical and clinical activity thus far, we have further narrowed our internal development focus to our nearest term opportunities, especially where human activity has been shown in our early-stage clinical trials. This focus is primarily on preclinical and clinical activities with Annamycin, preclinical activities associated with an intravenous version of WP1066 and IND-enabling studies of WP1122. We intend to rely on external funding, to the extent available, for other projects. Due to the COVID-19 pandemic, we have accelerated development of the WP1122 portfolio with a combined effort of internally and externally funded preclinical work to support an IND application with the FDA or an international regulator for the treatment of COVID-19 or a cancer indication or both. We believe our overall narrowing of focus will allow us to limit our cash needs to the essential opportunities until we reach a significant value inflection point, although we will continue to require additional external capital during this period. At this time we do not intend to pursue clinical trials for WP1122 for the treatment of COVID-19 and other viral diseases until we are able to secure external funding or collaborations for such trials.

S-2

Of our three clinical stage drug candidates, Annamycin is currently in a Phase 1 clinical trial for the treatment of AML in Poland. We recently received clearance from the FDA to proceed with a Phase 1 clinical trial of Annamycin as a potential treatment of soft tissue sarcomas (STS) metastasized to the lungs. WP1066, an Immune/Transcription Modulator (p-STAT3 inhibitor), is intended to target a wide range of tumors, including brain tumors such as glioblastoma (GBM) and pediatric brain tumors (like diffuse intrinsic pontine glioma, or DIPG, and medulloblastoma), as well as pancreatic cancer. It is currently in two investigator-initiated Phase 1 clinical trials, one for adult GBM and another for pediatric brain tumors (including DIPG and medulloblastoma). We began and completed a "proof-of-concept" Phase 1 clinical trial in 2019 in Poland for a third drug, WP1220 (a molecule similar to WP1066), for the topical treatment of cutaneous T-cell lymphoma (CTCL). We are actively seeking collaboration with a strategic partner in the near term for external funding for the continued development of WP1220 in a Phase 2 clinical trial as a topical therapy for CTCL. We are also engaged in preclinical development of additional drug candidates, including additional Immune/Transcription Modulators, as well as antimetabolites, targeting glycolysis and glycosylation.

We consider Annamycin to be a "next generation" anthracycline, unlike any currently approved anthracyclines, as it is designed to avoid multidrug resistance mechanisms with little to no cardiotoxicity (two problems common to all currently approved anthracyclines). We recently received an independent expert cardiology assessment confirming the absence of cardiotoxicity in the first 19 patients treated with Annamycin in both our U.S. and European Phase 1 clinical trials. Annamycin is currently in a Phase 1/2 clinical trial in Europe with the Phase 1 portion of another Phase 1/2 AML trial having been recently concluded in the U.S., subject to continued patient observations. The U.S. trial met its primary endpoint of safety. As a result of discussions with the FDA, we will focus on establishing a recommended Phase 2 dose (RP2D) for a trial in Europe and generating additional safety and efficacy data as requested by the FDA. The trial in Poland is in its fifth cohort where patients are being treated at 240 mg/m². The second patient in that cohort experienced a dose limiting toxicity (DLT), secondarily related to concomitant medication not being withheld. The DLT was resolved, and that cohort will be expanded to a total of six patients. If a second DLT in this cohort occurs, then we would enroll three subjects that would be treated at 210 mg/m² to confirm the maximum tolerated dosage. If no additional DLT occurs in the current cohort, then we will progress to the sixth cohort at 300 mg/m².

We believe the impact of the COVID-19 pandemic is slowing the pace of our patient recruitment in our Polish Annamycin clinical trial. We cannot assess when such impact on our trial will be alleviated or if it will worsen.

In 2019, preclinical work on Annamycin demonstrated activity against certain cancers metastasized to the lungs. On December 17, 2020, we disclosed that the FDA is allowing our IND application to study Annamycin for the treatment of soft tissue sarcoma lung metastases. This allows us to begin a Phase 1b/2 clinical trial in the U.S. for patients with soft tissue sarcoma that has metastasized to the lungs after first-line therapy for their disease. On December 29, 2020, we disclosed that the FDA had granted Orphan Drug Designation (ODD) to Annamycin for treatment of soft tissue sarcomas, in addition to the existing ODD for Annamycin in relapsed or refractory AML. On February 2, 2021, we announced that a preclinical study in animals has confirmed a significant therapeutic benefit of Annamycin against metastatic osteosarcoma. Computerized tomography scans demonstrated that animals treated with Annamycin exhibited significant suppression of tumor growth and not a single death was observed in the treated animals, whereas significant tumor burden contributed to the rapid death of 90% of untreated animals. While the study continues, as of day 130, the survival rate for animals treated with Annamycin was 100%, compared with only 10% for untreated animals. We caution that this is preclinical animal data and we can provide no assurance that we will see similar results in our planned clinical trials.

S-3

WP1066 is one of several Immune/Transcription Modulators designed to stimulate an immune response to tumors by inhibiting the errant activity of Regulatory TCells (TRegs) while also inhibiting key oncogenic transcription factors, including p-STAT3 (phosphorylated signal transducer and activator of transcription 3), c-Myc (a celluar signal transducer named after a homologous avian virus called Myelocytomatosis) and HIF-1á (hypoxia inducible factor 1a). These transcription factors are widely sought targets that are believed to contribute to an increase in cell survival and proliferation, and the angiogenesis (coopting vasculature for blood supply), invasion, metastasis and inflammation associated with tumors. They may also play a role in the inability of immune checkpoint inhibitors to affect more resistant tumors. WP1066 is currently in two U.S. physician-sponsored Phase 1 clinical trials, one at MD Anderson for the treatment of GBM in adults and another at Emory University for the treatment of pediatric brain tumors. The trial at MD Anderson has begun the fourth and final cohort in the dose escalation phase. The Emory trial has now successfully treated three patients in the first cohort and the first patient in the second cohort has begun treatment at the dose level of 6mg/kg. In that trial, one of the patients with DIPG showed an apparent response to the treatment with both clinical improvement and radiologic reduction of tumor size. We caution that this is incomplete preliminary data and no conclusions should be drawn from this single event. Another physician-sponsored Phase 1 trial is being considered for the treatment of GBM with WP1066 in combination with radiation, although no assurances can be given that such trial will begin.

Although WP1122 is a prodrug of 2-DG, the WP1122 Portfolio includes other antimetabolites comprising alternate sugar structures that may also prove useful as antiviral and/or anticancer therapies. The Company is currently evaluating some of these other antimetabolite molecules for potential translational development.

Our principal executive office is located at 5300 Memorial Drive, Suite 950, Houston, Texas 77007. Our website address is www.moleculin.com. Information contained in, or accessible through, our website does not constitute part of this prospectus supplement and inclusions of our website address in this prospectus supplement are inactive textual references only.

Recent Developments

On January 29, 2021, pursuant to authority granted by our stockholders, our board of directors approved a one-for-six reverse stock split of our common stock and the filing of an amendment to our amended and restated certificate of incorporation to effectuate the reverse stock split. The amendment was filed with the Secretary of State of the State of Delaware and the reverse stock split became effective in accordance with the terms of the amendment at 5:00 p.m. Eastern Time on January 29, 2021 (the “Effective Time”). The amendment provides that, at the Effective Time, every six shares of our issued and outstanding common stock will automatically be combined into one issued and outstanding share of common stock, without any change in par value per share, which will remain $0.001.

As a result of the reverse stock split, proportionate adjustments were made to the per share exercise price and/or the number of shares issuable upon the exercise or vesting of all outstanding stock options, restricted stock unit awards and warrants, which resulted in a proportional decrease in the number of shares of our common stock reserved for issuance upon exercise or vesting of such stock options, restricted stock unit awards and warrants, and, in the case of stock options and warrants, a proportional increase in the exercise price of all such stock options and warrants. In addition, the number of shares reserved for issuance under our equity compensation plan immediately prior to the Effective Time was reduced proportionately.

Unless otherwise noted, all share and per share numbers contained in this prospectus supplement are reflected on a post-split basis for all periods presented.

Implications of Being an Emerging Growth Company

We are an “emerging growth company,” as defined in the Jumpstart Our Business Startups Act, or the JOBS Act, enacted in April 2012, and we may remain an emerging company for up to five years from the closing of our IPO in May 2016. For so long as we remain an emerging growth company, we are permitted and intend to rely on certain exemptions from various public company reporting requirements, including not being required to have our internal control over financial reporting audited by our independent registered public accounting firm pursuant to Section 404(b) of the Sarbanes-Oxley Act of 2002, reduced disclosure obligations regarding executive compensation in our periodic reports and proxy statements, and exemptions from the requirements of holding a nonbinding advisory vote on executive compensation and any golden parachute payments not previously approved.

S-4

The Offering

Common stock offered by us	shares (       shares if the underwriters’ option to purchase additional shares is exercised in full), assuming the exercise in full of any pre-funded warrants
Pre-funded Warrants to be offered by us	We are also offering to certain purchasers whose purchase of shares of common stock in this offering would otherwise result in the purchaser, together with its affiliates and certain related parties, beneficially owning more than 4.99% (or, at the election of the purchaser, 9.99%) of our outstanding common stock immediately following the consummation of this offering, the opportunity to purchase, if such purchasers so choose, pre-funded warrants, in lieu of shares of common stock that would otherwise result in any such purchaser’s beneficial ownership exceeding 4.99% (or, at the election of the purchaser, 9.99%) of our outstanding common stock. Each pre-funded warrant will be exercisable for one share of our common stock. The purchase price of each pre-funded warrant will equal the price at which a  share of common stock is being sold to the public in this offering, minus $0.001, and the exercise price of each pre-funded warrant will be $0.001 per share. The pre-funded warrants will be exercisable immediately and may be exercised at any time until all of the pre-funded warrants are exercised in full. This offering also relates to the shares of common stock issuable upon exercise of any pre-funded warrants sold in this offering. For each pre-funded warrant we sell, the number of shares of common stock we are offering will be decreased on a one-for-one basis.
Over-allotment option	We have granted a 30-day option to the underwriters to purchase up to additional shares of common stock (up to 15% of the number of shares of common stock sold in the primary offering) solely to cover overallotments, if any.
Common stock to be outstanding after this offering	shares (       shares if the underwriters’ option to purchase additional shares is exercised in full), assuming the exercise in full of any pre-funded warrants.
Use of Proceeds	We expect to use the net proceeds from this offering for our planned clinical trials, preclinical programs, for other research and development activities and for general corporate purposes.  See “Use of Proceeds” on page S-9.
Risk Factors	Investing in our securities involves a high degree of risk. See “Risk Factors” beginning on page S-6 of this prospectus supplement and the risk factors in documents incorporated by reference into this prospectus supplement and the accompanying prospectus.
Nasdaq Capital Market Symbol	MBRX. We do not intend to list the pre-funded warrants on any securities exchange or nationally recognized trading system. Without an active trading market, the liquidity of the pre-funded warrants will be limited.

The number of shares of our common stock expected to be outstanding after this offering is based on 12,005,337 shares of common stock outstanding as of February 2, 2021, and excludes, as of that date, the following:

•     903,487 shares of common stock issuable upon the exercise of outstanding stock options, vested and unvested, with a weighted-average exercise price of $11.24 per share;

•     2,843,284 shares of common stock issuable upon the exercise of outstanding warrants with a weighted-average exercise price of $9.75 per share; and

•     up to an aggregate of 726,493 shares of common stock reserved for future issuance under our 2015 Stock Plan, as amended.

S-5

Risk Factors

An investment in our securities involves risks. We urge you to consider carefully the risks described below, and in the documents incorporated by reference in this prospectus supplement and the accompanying prospectus, before making an investment decision, including those risks identified under “Item IA. Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2019, which is incorporated by reference in this prospectus supplement and which may be amended, supplemented or superseded from time to time by other reports that we subsequently file with the SEC. If any of these risks actually occurs, our business, financial condition, results of operations or cash flow could be seriously harmed. This could cause the trading price of our common stock to decline, resulting in a loss of all or part of your investment. Please also read carefully the section below entitled “Cautionary Note Regarding Forward-Looking Statements”.

Risks Related to this Offering

You will experience immediate and substantial dilution in the book value per share of the common stock you purchase in the offering.

Because the public offering price per share of our common stock being offered is substantially higher than the net tangible book value per share of our outstanding common stock, you will suffer immediate and substantial dilution in the net tangible book value of the common stock you purchase in this offering. Investors purchasing shares of our common stock will incur immediate dilution of $                  per share, after giving effect to the sale of an aggregate of                  shares at the public offering price set forth on the cover page of this prospectus supplement, after deducting the underwriting discount and estimated offering expenses payable by us and assuming the exercise in full of any pre-funded warrant sold in this offering. See “Dilution” on page S-7 of this prospectus supplement for a more detailed discussion of the dilution you will incur if you purchase our common stock in this offering.

In addition, we may choose to raise additional capital due to market conditions or strategic considerations even if we believe we have sufficient funds for our current or future operating plans. To the extent that additional capital is raised through the sale of equity or convertible debt securities, the issuance of these securities could result in further dilution to our stockholders or result in downward pressure on the price of our common stock

Our management will have broad discretion over the use of the net proceeds from this offering, you may not agree with how we use the proceeds, and the proceeds may not be invested successfully.

Our management will have broad discretion in the application of the net proceeds from this offering, and our stockholders will not have the opportunity as part of their investment decision to assess whether the net proceeds are being used appropriately. Because of the number and variability of factors that will determine our use of the net proceeds from this offering, their ultimate use may vary substantially from their currently intended use. The failure by our management to apply these funds effectively could harm our business. See “Use of Proceeds” on page S-9 of this prospectus supplement for a description of our proposed use of proceeds from this offering.

We will require additional capital funding, the receipt of which may impair the value of our common stock.

Our future capital requirements depend on many factors, including our research, development, sales and marketing activities. We will need to raise additional capital through public or private equity or debt offerings or through arrangements with strategic partners or other sources in order to continue to develop our drug candidates.  There can be no assurance that additional capital will be available when needed or on terms satisfactory to us, if at all.  To the extent we raise additional capital by issuing equity securities, our stockholders may experience substantial dilution and the new equity securities may have greater rights, preferences or privileges than our existing common stock.

We cannot predict the effect that our reverse stock split will have on the market price for shares of our common stock.

On January 29, 2021, we completed a one-for-six reverse stock split of our shares of common stock and proportionate reduction in the number of authorized shares of common stock from approximately 72,000,000 shares to approximately 12,000,000. The reverse stock split was effected in accordance with the authorization adopted by our stockholders at our 2020 annual meeting of stockholders.

S-6

We cannot predict the effect that the reverse stock split will have on the market price for shares of our common stock, and the history of similar reverse stock splits for companies in like circumstances has varied. Some investors may have a negative view of a reverse stock split. Even if the reverse stock split has a positive effect on the market price for shares of our common stock, performance of our business and financial results, general economic conditions and the market perception of our business, and other adverse factors which may not be in our control could lead to a decrease in the price of our common stock following the reverse stock split.

Even if the reverse stock split does result in an increased market price per share of our common stock, the market price per share following the reverse stock split may not increase in proportion to the reduction of the number of shares of our common stock outstanding before the implementation of the reverse stock split. Accordingly, even with an increased market price per share, the total market capitalization of shares of our common stock after the reverse stock split could be lower than the total market capitalization before the reverse stock split. Also, even if there is an initial increase in the market price per share of our common stock after the reverse stock split, the market price many not remain at that level.

If the market price of shares of our common stock declines following the reverse stock split, the percentage decline as an absolute number and as a percentage of our overall market capitalization may be greater than would occur in the absence of the reverse stock split due to decreased liquidity in the market for our common stock. Accordingly, the total market capitalization of our common stock following the reverse stock split could be lower than the total market capitalization before the reverse stock split.

Our independent registered public accounting firm has indicated that our recurring losses from operations raise substantial doubt about our ability to continue as a going concern.

As described in their audit report, our auditors have included an explanatory paragraph that states that we had an accumulated deficit of $39.6 million at December 31, 2019 and have not generated any revenue from operations. These conditions raise substantial doubt about our ability to continue as a going concern. Our consolidated financial statements do not include any adjustments that might result from the outcome of this uncertainty. If we cannot continue as a viable entity, our securityholders may lose some or all of their investment in our company.

We do not intend to pay dividends in the foreseeable future.

We have never paid cash dividends on our common stock and currently do not plan to pay any cash dividends in the foreseeable future.

There is no public market for the pre-funded warrants being offered in this offering.

There is no established public trading market for the pre-funded warrants being offered in this offering, and we do not expect a market to develop. In addition, we do not intend to apply to list the pre-funded warrants on any securities exchange or nationally recognized trading system, including The Nasdaq Capital Market. Without an active market, the liquidity of the pre-funded warrants will be limited.

Holders of pre-funded warrants purchased in this offering will have no rights as common stockholders until such holders exercise their pre-funded warrants and acquire our common stock.

Until holders of pre-funded warrants acquire shares of our common stock upon exercise of their pre-funded warrants, holders of pre-funded warrants will have no rights with respect to the shares of our common stock underlying their pre-funded warrants. Upon exercise of the pre-funded warrants, the holders will be entitled to exercise the rights of a common stockholder only as to matters for which the record date occurs after the exercise date.

S-7

Cautionary Note Regarding Forward-Looking Statements

This prospectus supplement, the accompanying prospectus and the other documents we have filed with the SEC that are incorporated herein by reference contain forward-looking statements that involve substantial risks and uncertainties. All statements, other than statements of historical facts, regarding our strategy, future operations, future financial position, future revenues, projected costs, prospects, plans, objectives of management or other financial items are forward-looking statements. The words “anticipate,” “believe,” “estimate,” “expect,” “intend,” “may,” “plan,” “predict,” “project,” “will,” “would” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words.

Forward-looking statements include, but are not limited to, statements about:

● The impact the Coronavirus outbreak will have on our operations, including our clinical trials, preclinical activities and our ability to raise future financing;

● Our ability to continue our relationship with MD Anderson, including our ability to license future intellectual property resulting from our sponsored research agreements with MD Anderson;

● Our ability to obtain additional funding to commence or continue our clinical trials, fund operations and develop our product candidates;

● Our ability to satisfy any requirements imposed by the FDA (or its foreign equivalents) as a condition of our clinical trials proceeding or beginning as planned;

● The success, including the ability to recruit patients, of our clinical trials through all phases of clinical development;

● The need to obtain and retain regulatory approval of our drug candidates, both in the United States, in Poland, and in countries deemed necessary for future trials;

● Our ability to complete our clinical trials in a timely fashion and within our expected budget and resources;

● Compliance with obligations under intellectual property licenses with third parties;

● Any delays in regulatory review and approval of drug candidates in clinical development;

● Our ability to commercialize our drug candidates;

● Market acceptance of our drug candidates;

● Competition from existing therapies or new therapies that may emerge;

● Potential product liability claims;

● Our dependency on third-party manufacturers to successfully, and timely, supply or manufacture our drug candidates for our preclinical work and our clinical trials;

● Our ability to establish or maintain collaborations, licensing or other arrangements;

● The ability of our sublicense partners to successfully develop our product candidates in accordance with our sublicense agreements;

● Our ability and third parties’ abilities to protect intellectual property rights;

● Our ability to adequately support future growth; and

● Our ability to attract and retain key personnel to manage our business effectively.

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We may not actually achieve the plans, intentions or expectations disclosed in our forward-looking statements, and you should not place undue reliance on our forward-looking statements. Actual results or events could differ materially from the plans, intentions and expectations disclosed in the forward-looking statements we make. We have included important factors in the cautionary statements included in this prospectus supplement, particularly as set forth and incorporated by reference in the “Risk Factors” section above, that we believe could cause actual results or events to differ materially from the forward-looking statements that we make. Our forward-looking statements do not reflect the potential impact of any future acquisitions, mergers, dispositions, joint ventures, collaborations or investments we may make. You should read this prospectus supplement, the accompanying prospectus and the documents that we incorporate by reference in this prospectus supplement completely and with the understanding that our actual future results may be materially different from what we expect. We do not assume any obligation to update any forward-looking statements, except as otherwise required by law. We advise you, however, to consult any further disclosures we make on related subjects in our future annual reports on Form 10-K, quarterly reports on Form 10-Q and current reports on Form 8-K we file with or furnish to the SEC. 

Use of Proceeds

We estimate that the net proceeds from this offering will be approximately $        , or approximately $ million if the underwriters exercise their over-allotment option in full, after deducting the underwriting discount and estimated offering expenses payable by us.

We expect to use the net proceeds from this offering for our planned clinical trials, preclinical programs, for other research and development activities and for general corporate purposes. This represents our best estimate of the manner in which we will use the net proceeds we receive from this offering based upon the current status of our business, but we have not reserved or allocated amounts for specific purposes and we cannot specify with certainty how or when we will use any of the net proceeds. Amounts and timing of our actual expenditures will depend on numerous factors. Our management will have broad discretion in applying the net proceeds from this offering.

Dividend Policy

We have never declared or paid any cash dividends on our capital stock, and we do not currently intend to pay any cash dividends on our common stock for the foreseeable future. We expect to retain future earnings, if any, to fund the development and growth of our business. Any future determination to pay dividends on our common stock will be at the discretion of our board of directors and will depend upon, among other factors, our results of operations, financial condition, capital requirements and any contractual restrictions.

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Dilution

If you invest in our common stock in this offering, your interest will be diluted immediately to the extent of the difference between the public offering price per share of common stock in this offering and the as adjusted net tangible book value per share of our common stock immediately after this offering.

Our net tangible book value as of September 30, 2020 was approximately $3.3 million, or approximately $0.32 per share. Net tangible book value is determined by subtracting our total liabilities from our total tangible assets, and net tangible book value per share is determined by dividing our net tangible book value by the number of shares of our common stock outstanding. After giving effect to the sale of              shares of our common stock and       pre-funded warrants, and after deducting the underwriting discount and estimated offering expenses payable by us, our as adjusted net tangible book value as of September 30, 2020 would have been approximately $               , or approximately $             per share, assuming the exercise in full of any pre-funded warrants sold in this offering. This represents an immediate increase in net tangible book value of approximately $               per share to our existing stockholders and an immediate dilution of approximately $          per share to new investors participating in this offering. The following table illustrates this dilution on a per share basis:

Public offering price per share			$
Net tangible book value per share as of September 30, 2020	$	0.32
Increase in net tangible book value per share attributable to this offering	$
As adjusted net tangible book value per share after giving effect to this offering			$
Dilution per share to new investors participating in this offering			$

If the underwriters exercise their overallotment option in full, our as adjusted net tangible book value per share after giving effect to this offering would be $    per share and the dilution per share to new investors participating in this offering would be $   per share, assuming the exercise in full of any pre-funded warrants sold in this offering.

The above discussion and table are based on 10,294,038 shares of our common stock outstanding as of September 30, 2020, and excludes, as of that date, the following:

•     895,153 shares of common stock issuable upon the exercise of outstanding stock options, vested and unvested, with a weighted-average exercise price of $11.30 per share;

•     2,834,950 shares of common stock issuable upon the exercise of outstanding warrants with a weighted-average exercise price of $9.77 per share; and

•     up to an aggregate of 901,182 shares of common stock reserved for future issuance under our 2015 Stock Plan, as amended.

The above illustration of dilution per share to investors participating in this offering assumes the exercise in full of  any pre-funded warrants sold in this offering, and no exercise of outstanding options or warrants to purchase our common stock. The exercise of outstanding options or warrants, having an exercise or conversion price less than the offering price would increase dilution to investors participating in this offering. In addition, we may choose to raise additional capital depending on market conditions, our capital requirements and strategic considerations, even if we believe we have sufficient funds for our current or future operating plans. To the extent that additional capital is raised through our sale of equity or convertible debt securities, the issuance of these securities could result in further dilution to our stockholders.

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Description of Securities We are Offering

We are offering                shares of our common stock or pre-funded warrants to purchase shares of our common stock. This offering also relates to  the shares of common stock issuable from time to time upon exercise of the pre-funded warrants offered hereby.

Common Stock

The material terms and provisions of our common stock are described under the caption “Description of Common Stock” starting on page 4 of the accompanying prospectus.

Pre-Funded Warrants

The following summary of certain terms and provisions of the pre-funded warrants that are being offered hereby is not complete and is subject to, and qualified in its entirety by, the provisions of the pre-funded warrant, the form of which will be filed as an exhibit to a Current Report on Form 8-K that we will file with the SEC and that will be incorporated by reference into this prospectus supplement.

Duration and Exercise Price. Each pre-funded warrant offered hereby will have an initial exercise price per share equal to $0.001. The pre-funded warrants will be immediately exercisable and may be exercised at any time until the pre-funded warrants are exercised in full. The exercise price and number of shares of common stock issuable upon exercise is subject to appropriate adjustment in the event of stock dividends, stock splits, reorganizations or similar events affecting our common stock and the exercise price. The pre-funded warrants will be issued separately from the accompanying common warrants and may be transferred separately immediately thereafter.

Exercisability. The pre-funded warrants will be exercisable, at the option of each holder, in whole or in part, by delivering to us a duly executed exercise notice accompanied by payment in full for the number of shares of our common stock purchased upon such exercise (except in the case of a cashless exercise as discussed below). Purchasers of the pre-funded warrants in this offering may elect to deliver their exercise notice following the pricing of the offering and prior to the issuance of the pre-funded warrants at closing to have their pre-funded warrants exercised immediately upon issuance and receive shares of common stock underlying the pre-funded warrants upon closing of this offering. A holder (together with its affiliates) may not exercise any portion of the pre-funded warrant to the extent that the holder would own more than 4.99% of the outstanding common stock immediately after exercise, except that upon at least 61 days’ prior notice from the holder to us, the holder may increase the amount of ownership of outstanding stock after exercising the holder’s pre-funded warrants up to 9.99% of the number of shares of our common stock outstanding immediately after giving effect to the exercise, as such percentage ownership is determined in accordance with the terms of the pre-funded warrants. Purchasers of pre-funded warrants in this offering may also elect prior to the issuance of the pre-funded warrants to have the initial exercise limitation set at 9.99% of our outstanding common stock. No fractional shares of common stock will be issued in connection with the exercise of a pre-funded warrant. In lieu of fractional shares, we will round down to the next whole share.

Cashless Exercise. If, at the time a holder exercises its pre-funded warrants, a registration statement registering the issuance of the shares of common stock underlying the pre-funded warrants under the Securities Act is not then effective or available, then in lieu of making the cash payment otherwise contemplated to be made to us upon such exercise in payment of the aggregate exercise price, the holder may elect instead to receive upon such exercise (either in whole or in part) the net number of shares of common stock determined according to a formula set forth in the pre-funded warrants.

Transferability. Subject to applicable laws, a pre-funded warrant may be transferred at the option of the holder upon surrender of the pre-funded warrant to us together with the appropriate instruments of transfer.

Exchange Listing. There is no trading market available for the pre-funded warrants on any securities exchange or nationally recognized trading system. We do not intend to list the pre-funded warrants on any securities exchange or nationally recognized trading system. Without an active trading market, the liquidity of the pre-funded warrants will be limited.

Right as a Stockholder. Except as otherwise provided in the pre-funded warrants or by virtue of such holder’s ownership of shares of our common stock, the holders of the pre-funded warrants do not have the rights or privileges of holders of our common stock, including any voting rights, until they exercise their pre-funded warrants.

Fundamental Transaction. In the event of a fundamental transaction, as described in the pre-funded warrants and generally including any reorganization, recapitalization or reclassification of our common stock, the sale, transfer or other disposition of all or substantially all of our properties or assets, our consolidation or merger with or into another person, the acquisition of more than 50% of our outstanding common stock, or any person or group becoming the beneficial owner of 50% of the voting power represented by our outstanding common stock, the holders of the pre-funded warrants will be entitled to receive upon exercise of the pre-funded warrants the kind and amount of securities, cash or other property that the holders would have received had they exercised the pre-funded warrants immediately prior to such fundamental transaction.

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Underwriting

We have entered into an underwriting agreement with the underwriters named belowOppenheimer & Co. Inc. is acting as the sole book-running manager and representative of the underwriters.

The underwriting agreement provides for the purchase of a specific number of shares of common stock and/or pre-funded warrants by each of the underwriters. The underwriters’ obligations are several, which means that each underwriter is required to purchase a specified number of shares of common stock, but is not responsible for the commitment of any other underwriter to purchase shares of common stock and/or pre-funded warrants. Subject to the terms and conditions of the underwriting agreement, each underwriter has severally agreed to purchase the number of shares of common stock and/or pre-funded warrants set forth opposite its name below:

Underwriter	Number of Shares	Number of Pre-Funded Warrants
Oppenheimer & Co. Inc.
Total

The underwriters have agreed to purchase all of the shares of common stock and pre-funded warrants offered by this prospectus supplement (other than those covered by the option to purchase additional shares of common stock described below), if any are purchased. Under the underwriting agreement, if an underwriter defaults in its commitment to purchase shares of common stock and pre-funded warrants, the commitments of non-defaulting underwriters may be increased or the underwriting agreement may be terminated, depending on the circumstances.

The shares of common stock and pre-funded warrants offered hereby are expected to be ready for delivery on or about            , 2021 against payment in immediately available funds.

The underwriters are offering the shares of common stock and pre-funded warrants subject to various conditions and may reject all or part of any order. The representative of the underwriters has advised us that the underwriters propose to offer the shares of common stock and pre-funded warrants directly to the public at the public offering prices set forth on the cover page of this prospectus supplement. In addition, the representative may offer some of the shares of common stock and pre-funded warrants to other securities dealers at such price less a concession not in excess of $         per share or $       per pre-funded warrant. After the shares of common stock and pre-funded warrants are released for sale to the public, the representative may change the offering prices and other selling terms at various times.

The following table provides information regarding the amount of the discount to be paid to the underwriters by us, before expenses: 

			Total
	Per Share	Per Pre-Funded Warrant	Without Exercise of Option	With Full Exercise of Option
Public offering price	$	$	$	$
Underwriting discount	$	$	$	$
Proceeds to us (before expenses)	$	$	$	$

We have also agreed, subject to certain conditions, to provide Oppenheimer & Co. Inc. with a right of first refusal to act as sole book-running underwriter, sole initial purchaser, sole placement agent, or sole selling agent, as the case may be, on any financing for us on or before            , 2021.

We estimate that our total expenses of the offering, excluding the estimated underwriting discount, will be approximately $            , which includes the fees and expenses for which we have agreed to reimburse the underwriters, provided that any such fees and expenses in excess of an aggregate of $50,000 will be subject to our prior written approval (such approval not to be unreasonably withheld, conditioned or delayed).

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We have agreed to indemnify the underwriters against certain liabilities, including liabilities under the Securities Act of 1933.

We have granted an option to the underwriters, exercisable for 30 days after the date of this prospectus supplement, to purchase up to additional shares of our common stock at the public offering price per share, less the underwriting discount. If the underwriters exercise all or part of this option, they will purchase shares of our common stock covered by the option at the public offering price per share that appears on the cover page of this prospectus supplement, less the underwriting discount. If this option is exercised in full, the total price to the public will be $   , and the proceeds (before expenses) to us will be $  . If the underwriters exercise this option, the underwriters will be obligated, subject to the conditions contained in the underwriting agreement, to purchase a number of additional shares proportionate to that underwriter’s amount reflected in the above table.

We have agreed to a 90-day “lock-up” and our executive officers and directors have agreed to a 90-day “lock-up” with respect to shares of our common stock and other securities beneficially owned, including securities that are convertible into, or exchangeable or exercisable for, shares of our common stock. Subject to certain exceptions, during the applicable lock-up period following the date of this prospectus supplement, we and our executive officers and directors may not offer, sell, pledge or otherwise dispose of these securities without the prior written consent of Oppenheimer & Co. Inc.

Until the distribution of the shares and the pre-funded warrants is completed, SEC rules may limit the underwriters and selling group members from bidding for and purchasing our common stock. However, the underwriters may engage in transactions that stabilize the price of the common stock, such as bids or purchases to peg, fix or maintain that price. In connection with this offering, the underwriters may purchase and sell our common stock in the open market. These transactions may include short sales, purchases on the open market to cover positions created by short sales and stabilizing transactions. Short sales involve the sale by the underwriters of a greater number of shares than it is required to purchase in this offering. "Covered" short sales are sales made in an amount not greater than the underwriters' over-allotment option described above. The underwriters may close out any covered short position by either exercising its over-allotment option or purchasing shares in the open market. In determining the source of shares to close out the covered short position, the underwriters will consider, among other things, the price of shares available for purchase in the open market as compared to the price at which it may purchase shares through the option granted to it under the underwriting agreement described above. "Naked" short sales are sales in excess of such over-allotment option. The underwriters must close out any naked short position by purchasing shares in the open market. A naked short position is more likely to be created if the underwriters are concerned that there may be downward pressure on the price of our common stock in the open market after pricing that could adversely affect investors who purchase in this offering. Stabilizing transactions consist of various bids for or purchases of shares of common stock made by the underwriters in the open market prior to the closing of this offering.

Similar to other purchase transactions, the underwriters' purchases to cover short sales may have the effect of raising or maintaining the market price of our common stock or preventing or retarding a decline in the market price of our common stock. As a result, the price of our common stock may be higher than the price that might otherwise exist in the open market. The underwriters may conduct these transactions on the Nasdaq Capital Market, in the over-the-counter market or otherwise.

Neither we nor the underwriters make any representation or prediction as to the direction or magnitude of any effect that the transactions described above may have on the price of our common stock. In addition, neither we nor the underwriters make any representation that the underwriters will engage in these transactions or that these transactions, once commenced, will not be discontinued without notice.

The underwriters may also engage in passive market making transactions in our common stock on the Nasdaq Capital Market in accordance with Rule 103 of Regulation M during a period before the commencement of offers or sales of shares of our common stock in this offering and extending through the completion of distribution. A passive market maker must display its bid at a price not in excess of the highest independent bid of that security. However, if all independent bids are lowered below the passive market maker's bid, that bid must then be lowered when specified purchase limits are exceeded.

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Electronic Delivery of Preliminary Prospectus Supplement: A preliminary prospectus supplement in electronic format may be delivered to potential investors by one or more of the underwriters participating in this offering. The preliminary prospectus supplement in electronic format will be identical to the paper version of such preliminary prospectus supplement. Other than the preliminary prospectus supplement in electronic format, the information on any underwriter’s website and any information contained in any other website maintained by an underwriter is not part of this prospectus supplement, the accompanying prospectus or the registration statement of which this prospectus supplement and the accompanying prospectus form a part.

The underwriters and their affiliates have provided in the past and may provide from time to time in the future certain commercial banking, financial advisory, investment banking and other services for us and our affiliates in the ordinary course of their business, for which they may receive customary fees and commissions. In addition, from time to time, the underwriters and their affiliates may effect transactions for their own account or the accounts of customers, and hold on behalf of itself or its customers, long or short positions in our debt or equity securities or loans, and may do so in the future. Oppenheimer & Co. Inc. acts as the sales agent pursuant to the terms of our at market issuance sales agreement. During the 180 days prior to the date of this prospectus supplement, we have paid Oppenheimer & Co. Inc. total commissions of $172,369 and reimbursed it for total expenses of $25,732 under that agreement.

Notice to Prospective Investors in the European Economic Area

In relation to each member state of the European Economic Area that has implemented the Prospectus Directive (each, a relevant member state), with effect from and including the date on which the Prospectus Directive is implemented in that relevant member state (the relevant implementation date), an offer of our securities described in this prospectus supplement and the accompanying prospectus may not be made to the public in that relevant member state other than:

• to any legal entity which is a qualified investor as defined in the Prospectus Directive;

• to fewer than 100 or, if the relevant member state has implemented the relevant provision of the 2010 PD Amending Directive, 150 natural or legal persons (other than qualified investors as defined in the Prospectus Directive), as permitted under the Prospectus Directive, subject to obtaining the prior consent of the relevant Dealer or Dealers nominated by us for any such offer; or

• in any other circumstances falling within Article 3(2) of the Prospectus Directive,

provided that no such offer of shares of our common stock shall require us or the underwriters to publish a prospectus pursuant to Article 3 of the Prospectus Directive.

For purposes of this provision, the expression an “offer of securities to the public” in any relevant member state means the communication in any form and by any means of sufficient information on the terms of the offer and our securities to be offered so as to enable an investor to decide to purchase or subscribe for any securities, as the expression may be varied in that member state by any measure implementing the Prospectus Directive in that member state, the expression “Prospectus Directive” means Directive 2003/71/EC (and amendments thereto, including the 2010 PD Amending Directive, to the extent implemented in the relevant member state) and includes any relevant implementing measure in the relevant member state, and the expression “2010 PD Amending Directive” means Directive 2010/73/EU.

We and the underwriters have not authorized and do not authorize the making of any offer of our securities through any financial intermediary on our or their behalf, other than offers made by the underwriters with a view to the final placement of our securities as contemplated in this prospectus supplement and the accompanying prospectus. Accordingly, no purchaser of our securities, other than the underwriters, is authorized to make any further offer of our securities on behalf of us or the underwriters.

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Notice to Prospective Investors in the United Kingdom

This prospectus supplement and the accompanying prospectus are only being distributed to, and is only directed at, persons in the United Kingdom that are qualified investors within the meaning of Article 2(1)(e) of the Prospectus Directive that are also (i) investment professionals falling within Article 19(5) of the Financial Services and Markets Act 2000 (Financial Promotion) Order 2005, or the Order, or (ii) high net worth entities, and other persons to whom it may lawfully be communicated, falling within Article 49(2)(a) to (d) of the Order (each such person being referred to as a relevant person).

This prospectus supplement and the accompanying prospectus and their contents are confidential and should not be distributed, published or reproduced (in whole or in part) or disclosed by recipients to any other persons in the United Kingdom. Any person in the United Kingdom that is not a relevant person should not act or rely on this document or any of its contents.

Notice to Prospective Investors in Canada

This document constitutes an “exempt offering document” as defined in and for the purposes of applicable Canadian securities laws. No prospectus has been filed with any securities commission or similar regulatory authority in Canada in connection with the offer and sale of the securities described herein (the “Securities”). No securities commission or similar regulatory authority in Canada has reviewed or in any way passed upon this document or on the merits of the Securities and any representation to the contrary is an offence.

Canadian investors are advised that this document has been prepared in reliance on section 3A.3 of National Instrument 33-105 Underwriting Conflicts (“NI 33-105”). Pursuant to section 3A.3 of NI 33-105, this document is exempt from the requirement to provide investors with certain conflicts of interest disclosure pertaining to “connected issuer” and/or “related issuer” relationships as would otherwise be required pursuant to subsection 2.1(1) of NI 33-105.

Resale Restrictions

The offer and sale of the securities in Canada is being made on a private placement basis only and is exempt from the requirement to prepare and file a prospectus under applicable Canadian securities laws. Any resale of Securities acquired by a Canadian investor in this offering must be made in accordance with applicable Canadian securities laws, which may vary depending on the relevant jurisdiction, and which may require resales to be made in accordance with Canadian prospectus requirements, a statutory exemption from the prospectus requirements, in a transaction exempt from the prospectus requirements or otherwise under a discretionary exemption from the prospectus requirements granted by the applicable local Canadian securities regulatory authority. These resale restrictions may under certain circumstances apply to resales of the Securities outside of Canada.

Representations of Purchasers

Each Canadian investor who purchases the Securities will be deemed to have represented to the issuer and to each dealer from whom a purchase confirmation is received, as applicable, that the investor (i) is purchasing as principal, or is deemed to be purchasing as principal in accordance with applicable Canadian securities laws, for investment only and not with a view to resale or redistribution; (ii) is an “accredited investor” as such term is defined in section 1.1 of National Instrument 45-106 Prospectus Exemptions (“NI 45-106”) or, in Ontario, as such term is defined in section 73.3(1) of the Securities Act (Ontario); and (iii) is a “permitted client” as such term is defined in section 1.1 of National Instrument 31-103 Registration Requirements, Exemptions and Ongoing Registrant Obligations.

Taxation and Eligibility for Investment

Any discussion of taxation and related matters contained in this document does not purport to be a comprehensive description of all of the tax considerations that may be relevant to a Canadian investor when deciding to purchase the securities and, in particular, does not address any Canadian tax considerations. No representation or warranty is hereby made as to the tax consequences to a resident, or deemed resident, of Canada of an investment in the securities or with respect to the eligibility of the securities for investment by such investor under relevant Canadian federal and provincial legislation and regulations.

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Rights of Action for Damages or Rescission

Securities legislation in certain of the Canadian jurisdictions provides certain purchasers of securities pursuant to an offering memorandum, including where the distribution involves an “eligible foreign security” as such term is defined in Ontario Securities Commission Rule 45-501 Ontario Prospectus and Registration Exemptions and in Multilateral Instrument 45-107 Listing Representation and Statutory Rights of Action Disclosure Exemptions, as applicable, with a remedy for damages or rescission, or both, in addition to any other rights they may have at law, where the offering memorandum, or other offering document that constitutes an offering memorandum, and any amendment thereto, contains a “misrepresentation” as defined under applicable Canadian securities laws. These remedies, or notice with respect to these remedies, must be exercised or delivered, as the case may be, by the purchaser within the time limits prescribed under, and are subject to limitations and defences under, applicable Canadian securities legislation. In addition, these remedies are in addition to and without derogation from any other right or remedy available at law to the investor.

Language of Documents

Upon receipt of this document, each Canadian investor hereby confirms that it has expressly requested that all documents evidencing or relating in any way to the sale of the Securities described herein (including for greater certainty any purchase confirmation or any notice) be drawn up in the English language only. Par la réception de ce document, chaque investisseur canadien confirme par les présentes qu’il a expressément exigé que tous les documents faisant foi ou se rapportant de quelque manière que ce soit à la vente des valeurs mobilières décrites aux présentes (incluant, pour plus de certitude, toute confirmation d’achat ou tout avis) soient rédigés en anglais seulement.

Notice to Prospective Investors in Australia

No prospectus or other disclosure document (as defined in the Corporations Act 2001 (Cth) of Australia, or Corporations Act) in relation to our securities has been or will be lodged with the Australian Securities & Investments Commission, or ASIC. This document has not been lodged with ASIC and is only directed to certain categories of exempt persons. Accordingly, if you receive this document in Australia you confirm and warrant that you are either:

• a “sophisticated investor” under section 708(8)(a) or (b) of the Corporations Act;

• a “sophisticated investor” under section 708(8)(c) or (d) of the Corporations Act and that you have provided an accountant’s certificate to us which complies with the requirements of section 708(8)(c)(i) or (ii) of the Corporations Act and related regulations before the offer has been made;

• a person associated with the company under section 708(12) of the Corporations Act; or

• a “professional investor” within the meaning of section 708(11)(a) or (b) of the Corporations Act, and to the extent that you are unable to confirm or warrant that you are an exempt sophisticated investor, associated person or professional investor under the Corporations Act any offer made to you under this document is void and incapable of acceptance; and

• you warrant and agree that you will not offer any of our securities for resale in Australia within 12 months of those securities being issued unless any such resale offer is exempt from the requirement to issue a disclosure document under section 708 of the Corporations Act.

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Notice to Prospective Investors in France

Neither this prospectus supplement, the accompanying prospectus nor any other offering material relating to our securities described in this prospectus supplement and the accompanying prospectus has been submitted to the clearance procedures of the Autorité des Marchés Financiers or of the competent authority of another member state of the European Economic Area and notified to the Autorité des Marchés Financiers. These securities have not been offered or sold and will not be offered or sold, directly or indirectly, to the public in France. Neither this prospectus supplement, the accompanying prospectus nor any other offering material relating to our securities has been or will be:

• released, issued, distributed or caused to be released, issued or distributed to the public in France; or

• used in connection with any offer for subscription or sale of our securities to the public in France.

Such offers, sales and distributions will be made in France only:

• to qualified investors (investisseurs qualifiés) and/or to a restricted circle of investors (cercle restreint d’investisseurs), in each case investing for their own account, all as defined in, and in accordance with articles L.411-2, D.411-1, D.411-2, D.734-1, D.744-1, D.754-1 and D.764-1 of the French Code monétaire et financier;

• to investment services providers authorized to engage in portfolio management on behalf of third parties; or

• in a transaction that, in accordance with article L.411-2-II-1°-or-2°-or 3° of the French Code monétaire et financier and article 211-2 of the General Regulations (Règlement Général) of the Autorité des Marchés Financiers, does not constitute a public offer (appel public à l’épargne).

Our securities may be resold directly or indirectly, only in compliance with articles L.411-1, L.411-2, L.412-1 and L.621-8 through L.621-8-3 of the French Code monétaire et financier.

Notice to Prospective Investors in Chile

Our securities are not registered in the Securities Registry (Registro de Valores) or subject to the control of the Chilean Securities and Exchange Commission (Superintendencia de Valores y Seguros de Chile). This prospectus supplement, the accompanying prospectus and other offering materials relating to the offer of the securities do not constitute a public offer of, or an invitation to subscribe for or purchase, the shares in the Republic of Chile, other than to individually identified purchasers pursuant to a private offering within the meaning of Article 4 of the Chilean Securities Market Act (Ley de Mercado de Valores) (an offer that is not “addressed to the public at large or to a certain sector or specific group of the public”).

Notice to Prospective Investors in Hong Kong

Our securities may not be offered or sold in Hong Kong by means of any document other than (i) in circumstances which do not constitute an offer to the public within the meaning of the Companies Ordinance (Cap. 32, Laws of Hong Kong), or (ii) to “professional investors” within the meaning of the Securities and Futures Ordinance (Cap. 571, Laws of Hong Kong) and any rules made thereunder, or (iii) in other circumstances which do not result in the document being a “prospectus” within the meaning of the Companies Ordinance (Cap. 32, Laws of Hong Kong) and no advertisement, invitation or document relating to our securities may be issued or may be in the possession of any person for the purpose of issue (in each case whether in Hong Kong or elsewhere), which is directed at, or the contents of which are likely to be accessed or read by, the public in Hong Kong (except if permitted to do so under the laws of Hong Kong) other than with respect to our securities which are or are intended to be disposed of only to persons outside Hong Kong or only to “professional investors” within the meaning of the Securities and Futures Ordinance (Cap. 571, Laws of Hong Kong) and any rules made thereunder.

Notice to Prospective Investors in the State of Israel

In the State of Israel this prospectus supplement and the accompanying prospectus shall not be regarded as an offer to the public to purchase securities under the Israeli Securities Law, 5728-1968, which requires a prospectus to be published and authorized by the Israel Securities Authority, if they comply with certain provisions of Section 15 of the Israeli Securities Law, 5728-1968, including, inter alia, if: (i) the offer is made, distributed or directed to not more than 35 investors, subject to certain conditions (the “Addressed Investors”); or (ii) the offer is made, distributed or directed to certain qualified investors defined in the First Addendum of the Israeli Securities Law, 5728-1968, subject to certain conditions (the “Qualified Investors”). The Qualified Investors shall not be taken into account in the count of the Addressed Investors and may be offered to purchase securities in addition to the 35 Addressed Investors. The company has not and will not take any action that would require it to publish a prospectus in accordance with and subject to the Israeli Securities Law, 5728-1968. We have not and will not distribute this prospectus or make, distribute or direct an offer to subscribe for our securities to any person within the State of Israel, other than to Qualified Investors and up to 35 Addressed Investors.

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Qualified Investors may have to submit written evidence that they meet the definitions set out in of the First Addendum to the Israeli Securities Law, 5728-1968. In particular, we may request, as a condition to be offered securities, that Qualified Investors will each represent, warrant and certify to us and/or to anyone acting on our behalf: (i) that it is an investor falling within one of the categories listed in the First Addendum to the Israeli Securities Law, 5728-1968; (ii) which of the categories listed in the First Addendum to the Israeli Securities Law, 5728-1968 regarding Qualified Investors is applicable to it; (iii) that it will abide by all provisions set forth in the Israeli Securities Law, 5728-1968 and the regulations promulgated thereunder in connection with the offer to be issued common stock; (iv) that the securities that it will be issued are, subject to exemptions available under the Israeli Securities Law, 5728-1968: (a) for its own account; (b) for investment purposes only; and (c) not issued with a view to resale within the State of Israel, other than in accordance with the provisions of the Israeli Securities Law, 5728-1968; and (v) that it is willing to provide further evidence of its Qualified Investor status. Addressed Investors may have to submit written evidence in respect of their identity and may have to sign and submit a declaration containing, inter alia, the Addressed Investor’s name, address and passport number or Israeli identification number.

Notice to Prospective Investors in Japan

Our securities offered in this prospectus supplement and the accompanying prospectus have not been and will not be registered under the Financial Instruments and Exchange Law of Japan. Our securities have not been offered or sold and will not be offered or sold, directly or indirectly, in Japan or to or for the account of any resident of Japan (including any corporation or other entity organized under the laws of Japan), except (i) pursuant to an exemption from the registration requirements of the Financial Instruments and Exchange Law and (ii) in compliance with any other applicable requirements of Japanese law.

Notice to Prospective Investors in Singapore

This prospectus supplement and the accompanying prospectus have not been registered as a prospectus with the Monetary Authority of Singapore. Accordingly, this prospectus supplement and the accompanying prospectus and any other document or material in connection with the offer or sale, or invitation for subscription or purchase, of our securities may not be circulated or distributed, nor may our securities be offered or sold, or be made the subject of an invitation for subscription or purchase, whether directly or indirectly, to persons in Singapore other than (i) to an institutional investor under Section 274 of the Securities and Futures Act, Chapter 289 of Singapore, or the SFA, (ii) to a relevant person pursuant to Section 275(1), or any person pursuant to Section 275(1A), and in accordance with the conditions specified in Section 275 of the SFA or (iii) otherwise pursuant to, and in accordance with the conditions of, any other applicable provision of the SFA, in each case subject to compliance with conditions set forth in the SFA.

Where our securities are subscribed or purchased under Section 275 of the SFA by a relevant party which is:

• a corporation (which is not an accredited investor (as defined in Section 4A of the SFA)) the sole business of which is to hold investments and the entire share capital of which is owned by one or more individuals, each of whom is an accredited investor; or

• a trust (where the trustee is not an accredited investor) whose sole purpose is to hold investments and each beneficiary of the trust is an individual who is an accredited investor, shares, debentures and units of our securities and debentures of that corporation or the beneficiaries’ rights and interest (howsoever described) in that trust shall not be transferred within six months after that corporation or that trust has acquired our securities pursuant to an offer made under Section 275 of the SFA except:

• to an institutional investor (for corporations, under Section 274 of the SFA) or to a relevant person defined in Section 275(2) of the SFA, or to any person pursuant to an offer that is made on terms that such shares, debentures and units of our securities and debentures of that corporation or such rights and interest in that trust are acquired at a consideration of not less than $200,000 (or its equivalent in a foreign currency) for each transaction, whether such amount is to be paid for in cash or by exchange of securities or other assets, and further for corporations, in accordance with the conditions specified in Section 275 of the SFA;

• where no consideration is or will be given for the transfer; or

• where the transfer is by operation of law.

S-18

Legal Matters

The validity of the shares of common stock offered hereby will be passed upon for us by Schiff Hardin LLP, Washington, DC. Lowenstein Sandler LLP, New York, New York, is acting as counsel for the underwriters in connection with this offering.

Experts

The audited financial statements incorporated by reference in this prospectus and elsewhere in the registration statement have been incorporated by reference in reliance upon the reports of Grant Thornton LLP, independent registered public accountants, upon the authority of said firm as experts in accounting and auditing.

Incorporation by Reference

The SEC allows us to “incorporate by reference” into this prospectus supplement the information in other documents that we file with it. This means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be a part of this prospectus supplement, and information in documents that we file later with the SEC will automatically update and supersede information contained in documents filed earlier with the SEC or contained in this prospectus supplement. We incorporate by reference in this prospectus supplement the documents listed below and any future filings that we may make with the SEC under Sections 13(a), 13(c), 14, or 15(d) of the Exchange Act prior to the termination of the offering under this prospectus supplement; provided, however, that we are not incorporating, in each case, any documents or information deemed to have been furnished and not filed in accordance with SEC rules:

●     Our Annual Report on Form 10-K for the year ended December 31, 2019 (filed on March 19, 2019);

●     Our Quarterly Reports on Form 10-Q for the quarters ended March 31, 2020 (filed on May 11, 2020); June 30, 2020 (filed on August 12, 2020); and September 30, 2020 (filed on November 12, 2020);

●     Our Current Reports on Form 8-K filed on February 3, 2020; February 5, 2020; February 6, 2020; February 18, 2020; February 20, 2020; March 10, 2020; March 17, 2020; March 26, 2020; April 2, 2020; April 8, 2020; April 14, 2020; April 17, 2020; April 23, 2020; May 18, 2020; May 27, 2020; May 28, 2020; June 16, 2020; June 17, 2020 (as amended on August 4, 2020); July 17, 2020; August 26, 2020; October 2, 2020; October 7, 2020; and January 29, 2021;

●     Definitive Proxy Statement on Schedule 14A relating to the Company’s 2020 Annual Meeting of Stockholders (filed on April 7, 2020); and

●     the description of our common stock, par value $0.001 per share contained in our Registration Statement on Form 8-A, dated and filed with the SEC on April 28, 2016, and any amendment or report filed with the SEC for the purpose of updating the description.

All reports and other documents we subsequently file pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act prior to the termination of this offering, including all such documents we may file with the SEC after the date of this prospectus supplement and accompanying prospectus, but excluding any information furnished to, rather than filed with, the SEC, will also be incorporated by reference into this prospectus supplement and deemed to be part of this prospectus supplement from the date of the filing of such reports and documents.

You may obtain a copy of any or all of the documents referred to above, which may have been or may be incorporated by reference into this prospectus supplement, including exhibits, at no cost to you by writing or telephoning us at the following address: Attention: Corporate Secretary, 5300 Memorial Drive, Suite 950, Houston, Texas 77007, telephone (713) 300-5160.

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Where You Can Find More Information

This prospectus supplement and the accompanying prospectus are part of a registration statement on Form S-3 we filed with the SEC under the Securities Act and do not contain all the information set forth or incorporated by reference in the registration statement. Whenever a reference is made in this prospectus supplement or the accompanying prospectus to any of our contracts, agreements or other documents, the reference may not be complete and you should refer to the exhibits that are a part of the registration statement or the exhibits to the reports or other documents incorporated by reference into this prospectus supplement or the accompanying prospectus for a copy of such contract, agreement or other document. Because we are subject to the information and reporting requirements of the Exchange Act, we file annual, quarterly and current reports, proxy statements and other information with the SEC. You may read and copy information filed by us with the SEC at the SEC’s public reference section, 100 F Street, N.E., Washington, D.C. 20549. Information regarding the operation of the public reference section can be obtained by calling 1-800-SEC-0330. The SEC also maintains an Internet site at http://www.sec.gov that contains reports, statements and other information about issuers, such as us, who file electronically with the SEC.

S-20

PROSPECTUS

$75,000,000

Moleculin Biotech, Inc.

Common Stock

Preferred Stock

Debt Securities

Warrants

Units

We may from time to time issue up to $75,000,000 aggregate dollar amount of common stock, preferred stock, debt securities, warrants or units of securities. We will specify in the accompanying prospectus supplement the terms of the securities to be offered and sold. We may sell these securities directly to you, through underwriters, dealers or agents we select, or through a combination of these methods. We will describe the plan of distribution for any particular offering of these securities in the applicable prospectus supplement. This prospectus may not be used to sell our securities unless it is accompanied by a prospectus supplement.

Our common stock is listed on The NASDAQ Capital Market and traded under the symbol “MBRX”. On March 19, 2020, the closing price of the common stock, as reported on NASDAQ was $0.65 per share. 

As of March 19, 2020, the aggregate market value of our outstanding common stock held by non-affiliates was approximately $30.1 million, based on 53,227,700 shares of outstanding common stock, of which approximately 46,314,768 shares were held by non-affiliates, and a per share price of $0.65 based on the closing sale price of our common stock on March 19, 2020.

Investing in our securities is highly speculative and involves a high degree of risk. You should purchase these securities only if you can afford a complete loss of your investment. You should carefully consider the risks and uncertainties described under the heading “Risk Factors” beginning on page 3 of this prospectus before making a decision to purchase our securities.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus is April 9, 2020.

Table of Contents

	Page
ABOUT THIS PROSPECTUS	1
WHERE YOU CAN FIND MORE INFORMATION	1
INCORPORATION BY REFERENCE	2
ABOUT MBI	3
RISK FACTORS	5
FORWARD-LOOKING STATEMENTS	5
USE OF PROCEEDS	5
DESCRIPTION OF COMMON STOCK	6
DESCRIPTION OF PREFERRED STOCK	8
DESCRIPTION OF DEBT SECURITIES	9
DESCRIPTION OF THE WARRANTS	17
DESCRIPTION OF THE STOCK PURCHASE CONTRACTS AND STOCK PURCHASE UNITS	19
PLAN OF DISTRIBUTION	19
LEGAL MATTERS	22
EXPERTS	22

-i-

ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement that we filed with the Securities and Exchange Commission, or the SEC, utilizing a “shelf” registration process. Under this shelf registration process, we may sell the securities described in this prospectus in one or more offerings up to a total dollar amount of $75,000,000.

We have provided to you in this prospectus a general description of the securities we may offer. Each time we sell securities under this shelf registration process, we will provide a prospectus supplement that will contain specific information about the terms of that offering. That prospectus supplement may include additional risk factors or other special considerations applicable to the securities being offered. We may also add, update or change in the prospectus supplement any of the information contained in this prospectus. To the extent there is a conflict between the information contained in this prospectus and the prospectus supplement, you should rely on the information in the prospectus supplement, provided that if a statement in any document is inconsistent with a statement in another document having a later date — for example, a document incorporated by reference in this prospectus or any prospectus supplement — the statement in the document having the later date modifies or supersedes the earlier statement. You should read both this prospectus and the prospectus supplement together with the additional information described under “Where You Can Find More Information.”

The registration statement containing this prospectus, including the exhibits to the registration statement, provides additional information about us and the securities offered under this prospectus. The registration statement, including the exhibits, can be read at the SEC website or at the SEC offices mentioned under the heading “Where You Can Find More Information.”

You should rely only on the information incorporated by reference or provided in this prospectus and the accompanying prospectus supplement. We have not authorized anyone to provide you with different information. We are not making an offer to sell or soliciting an offer to buy these securities in any jurisdiction in which the offer or solicitation is not authorized or in which the person making the offer or solicitation is not qualified to do so or to anyone to whom it is unlawful to make the offer or solicitation. You should not assume that the information in this prospectus or the accompanying prospectus supplement is accurate as of any date other than the date on the front of the document.

Unless the context requires otherwise, references to the "Company, " "we," "our," and "us," refer to Moleculin Biotech, Inc. and its subsidiaries, except that such terms refer to only Moleculin Biotech, Inc. and not its subsidiaries in the sections entitled "Description of Common Stock," "Description of Preferred Stock," "Description of Warrants," "Description of the Debt Securities," and "Description of the Stock Purchase Contracts and Stock Purchase Units."

WHERE YOU CAN FIND MORE INFORMATION

We have filed with the SEC a registration statement on Form S-3 under the Securities Act with respect to the securities offered in this offering. We file annual, quarterly and current reports, proxy statements and other information with the Securities and Exchange Commission. You may read and copy the registration statement and any other documents we have filed at the Securities and Exchange Commission’s Public Reference Room 100 F Street, N.E., Washington, D.C. 20549. Please call the Securities and Exchange Commission at 1-800-SEC-0330 for further information on the Public Reference Room. Our Securities and Exchange Commission filings are also available to the public at the Securities and Exchange Commission’s Internet site at www.sec.gov.

This prospectus is part of the registration statement and does not contain all of the information included in the registration statement. Whenever a reference is made in this prospectus to any of our contracts or other documents, the reference may not be complete and, for a copy of the contract or document, you should refer to the exhibits that are a part of the registration statement.

1

INCORPORATION BY REFERENCE

The SEC allows us to “incorporate by reference” into this prospectus the information we file with it, which means that we can disclose important information to you by referring you to those documents. Later information filed with the SEC will update and supersede this information.

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We incorporate by reference the documents listed below, all filings filed by us pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act after the date of the initial registration statement of which this prospectus forms a part prior to effectiveness of such registration statement, and any future filings we make with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act prior to the time that all securities covered by this prospectus have been sold or the offering is otherwise terminated; provided, however, that we are not incorporating any information furnished under either Item 2.02 or Item 7.01 of any current report on Form 8-K:

• Our Annual Report on Form 10-K for the year ended December 31, 2019 (filed on March 19, 2019);

• Our Current Reports on Form 8-K filed on February 3, 2020; February 5, 2020; February 6, 2020; February 18, 2020; February 20, 2020; March 10, 2020; and March 17, 2020;

• Definitive Proxy Statement on Schedule 14A filed on April 16, 2019 and our additional definitive proxy materials filed May 3, 2019; and

• the description of our common stock, par value $0.001 per share contained in our Registration Statement on Form 8-A, dated and filed with the SEC on April 28, 2016, and any amendment or report filed with the SEC for the purpose of updating the description.

An updated description of our capital stock is included in this prospectus under “Description of Common Stock” and “Description of Preferred Stock”.

We will provide to each person, including any beneficial owner, to whom this prospectus is delivered, upon written or oral request, at no cost to the requester, a copy of any and all of the information that is incorporated by reference in this prospectus. You may request a copy of these filings, at no cost, by contacting us at:

Moleculin Biotech, Inc.

Attn: Corporate Secretary

5300 Memorial Drive, Suite 950

Houston, TX 77007

Phone: 713-300-5160

ABOUT MOLECULIN BIOTECH, INC.

Our Company

We are a clinical stage pharmaceutical company focused on the treatment of highly resistant cancers. We have three core technologies, all of which are based on discoveries made at MD Anderson Cancer Center ("MD Anderson"). We have three drug candidates that are active in clinical trials. In 2019, those three drug candidates were active in four clinical trials in the US and Poland with a fifth that is expected to begin in the first half of 2020. Of these five clinical trials, two are primarily externally funded. For two of these trials, we successfully concluded the Phase 1 portion recently and are preparing to potentially move into Phase 2 trials. We anticipate laying the groundwork in 2020 for two additional Phase 1 trials expected to begin in 2021 sponsored by us and two other Phase 1 trials we expect to be externally sponsored.

Based on our positive clinical activity thus far, we have narrowed our development focus to our nearest term opportunities. We believe this will allow us to reduce our cash needs until we reach a significant value inflection point, although we will continue to require additional external capital during this period. In addition, institutional support for our technologies has increased and we believe such support may provide outside funding to help reduce future dilution.

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Of our three clinical stage drug candidates, Annamycin is being studied for the treatment of relapsed or refractory acute myeloid leukemia ("AML") and cancers metastasized to the lungs. WP1066, an Immune/Transcription Modulator ("p-STAT3 inhibitor") is intended to target a wide range of tumors, including brain tumors and pancreatic cancer. We began and completed a Phase 1 clinical trial in 2019 in Poland for a third drug, WP1220 (a molecule similar to WP1066), for the topical treatment of cutaneous T-cell lymphoma ("CTCL") and we are looking to expand development of this drug into a Moleculin Phase 2 trial. We are also engaged in preclinical development of additional drug candidates, including additional Immune/Transcription Modulators, as well as Metabolism/Glycosylation Inhibitors.

We consider Annamycin to be a "next generation" anthracycline, unlike any currently approved anthracyclines, as it is designed to avoid multidrug resistance mechanisms with little to no cardiotoxicity (two problems common to all currently approved anthracyclines). We recently received an independent expert cardiology assessment confirming the absence of cardiotoxicity in the first 14 patients treated with Annamycin in both our US and European Phase 1 clinical trials, validating Annamycin's lack of cardiotoxicity. Annamycin is currently in one Phase 1/2 clinical trial in Europe with the Phase 1 portion of another Phase 1/2 AML trial recently concluding in the US. Upon receipt of further data from the European Phase 1 trial, we plan to seek agreement with the FDA for accelerated approval of Annamycin based on a pivotal Phase 2 AML trial sponsored by us, although there is no assurance that the FDA will agree with our proposal.

In 2019, preclinical work on Annamycin demonstrated activity against some cancers metastasized to the lungs. With this new data, we are planning to start a Moleculin-sponsored US Phase 1 trial at MD Anderson for the treatment of cancer metastasized to the lungs with Annamycin.

WP1066 is one of several Immune/Transcription Modulators designed to stimulate the immune response to tumors by inhibiting the errant activity of Regulatory T-Cells (TRegs) while also inhibiting key oncogenic transcription factors, including p-STAT3, c-Myc and HIF-1. These transcription factors are widely sought targets that may also play a role in the inability of immune checkpoint inhibitors to affect more resistant tumors. WP1066 is currently in an US physician-sponsored Phase 1 trial for the treatment of glioblastoma ("GBM") and another institutionally sponsored Phase 1 trial should begin soon for the treatment of pediatric brain tumors. Another physician-sponsored Phase 1 trial is being considered for the treatment of GBM with WP1066 in combination with radiation.

We are also developing new compounds designed to exploit the potential uses of inhibitors of glycolysis such as 2-deoxy-D-glucose "2-DG"), which we believe may provide an opportunity to cut off the fuel supply of tumors by taking advantage of their high level of dependence on glucose in comparison to healthy cells. A key drawback to 2-DG is its lack of drug-like properties, including a short circulation time and poor tissue/organ distribution characteristics. Our lead Metabolism/Glycosylation Inhibitor, WP1122, is a prodrug of 2-DG that appears to improve the drug-like properties of 2-DG by increasing its circulation time and improving tissue/organ distribution. New research also points to the potential for 2-DG to be capable of enhancing the usefulness of checkpoint inhibitors. Considering that 2-DG lacks sufficient drug-like properties to be practical in a clinical setting, we believe WP1122 has the opportunity to become an important drug to potentiate existing therapies, including checkpoint inhibitors. In March 2020, we entered into an agreement with an outside research center who will conduct research on WP1122 for antiviral properties against a range of viruses, including Coronavirus.

We do not have manufacturing facilities and all manufacturing activities are contracted out to third parties. Additionally, we do not have a sales organization.

Corporate Information

Our principal executive office is located at 5300 Memorial Drive, Suite 950, Houston, Texas 77007. Our website address is www.moleculin.com. Information contained in, or accessible through, our website does not constitute part of this prospectus and inclusions of our website address in this prospectus are inactive textual references only.

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RISK FACTORS

Before making an investment decision, you should consider the “Risk Factors” included under Item 1A. of our most rcent Annual Report on Form 10-K and in our updates to those Risk Factors in our Quarterly Reports on Form 10-Q, all of which are incorporated by reference in this prospectus, as updated by our future filings with the SEC. The market or trading price of our common stock could decline due to any of these risks. In addition, please read “Forward-Looking Statements” in this prospectus, where we describe additional uncertainties associated with our business and the forward-looking statements included or incorporated by reference in this prospectus. Please note that additional risks not currently known to us or that we currently deem immaterial may also impair our business and operations. The accompanying prospectus supplement may contain a discussion of additional risks applicable to an investment in us and the particular type of securities we are offering under that prospectus supplement.

Forward-Looking Statements

Some of the information in this prospectus, and the documents we incorporate by reference, contain forward-looking statements within the meaning of the federal securities laws. You should not rely on forward-looking statements in this prospectus, and the documents we incorporate by reference. Forward-looking statements typically are identified by use of terms such as “anticipate,” “believe,” “plan,” “expect,” “future,” “intend,” “may,” “will,” “should,” “estimate,” “predict,” “potential,” “continue,” and similar words, although some forward-looking statements are expressed differently. This prospectus, and the documents we incorporate by reference, may also contain forward-looking statements attributed to third parties relating to their estimates regarding the markets we may enter in the future. All forward-looking statements address matters that involve risk and uncertainties, and there are many important risks, uncertainties and other factors that could cause our actual results to differ materially from the forward-looking statements contained in this prospectus, and the documents we incorporate by reference.

You should also consider carefully the statements under “Risk Factors” and other sections of this prospectus, and the documents we incorporate by reference, which address additional facts that could cause our actual results to differ from those set forth in the forward-looking statements. We caution investors not to place significant reliance on the forward-looking statements contained in this prospectus, and the documents we incorporate by reference. We undertake no obligation to publicly update or review any forward-looking statements, whether as a result of new information, future developments or otherwise.

USE OF PROCEEDS

We expect to use the net proceeds from the sale of securities offered by this prospectus and the prospectus supplement for our clinical trials, if any, and preclinical programs, for other research and development activities and for general corporate purposes. These may include additions to working capital, repayment of existing indebtedness and acquisitions. If we decide to use the net proceeds of any offering of securities other than for our clinical trials, if any, and preclinical programs, for other research and development activities and for general corporate purposes, we will describe the use of the net proceeds in the prospectus supplement for that offering.

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DESCRIPTION OF COMMON STOCK

General

We are currently authorized to issue 100,000,000 shares of common stock, par value $0.001. As of March 19, 2020, we had 53,227,700 shares of our common stock outstanding.

Subject to preferences that may be applicable to any preferred stock outstanding at the time, the holders of our common stock are entitled to receive dividends out of legally available assets at such times and in such amounts as our Board of Directors may from time to time determine. Each stockholder is entitled to one vote for each share of common stock held on all matters submitted to a vote of stockholders. Cumulative voting is not allowed.

Our common stock is not subject to conversion or redemption and holders of our common stock are not entitled to preemptive rights. Upon the liquidation, dissolution or winding up of our company, the remaining assets legally available for distribution to stockholders, after payment of claims or creditors and payment of liquidation preferences, if any, on outstanding preferred stock, are distributable ratably among the holders of our common stock and any participating preferred stock outstanding at that time. Each outstanding share of common stock is fully paid and nonassessable.

Anti-Takeover Effects of Provisions of Delaware Law and our Charter Documents

Provisions of Delaware law and our Amended and Restated Certificate of Incorporation (“Certificate of Incorporation”) and our Amended and Restated Bylaws (“Bylaws”) could make the acquisition of our company through a tender offer, a proxy contest or other means more difficult and could make the removal of incumbent officers and directors more difficult. We expect these provisions to discourage coercive takeover practices and inadequate takeover bids and to encourage persons seeking to acquire control of our company to first negotiate with our Board of Directors. We believe that the benefits provided by our ability to negotiate with the proponent of an unfriendly or unsolicited proposal outweigh the disadvantages of discouraging these proposals. We believe the negotiation of an unfriendly or unsolicited proposal could result in an improvement of its terms.

Our Bylaws do not permit stockholders to call a special meeting of stockholders. Our Bylaws provide that special meetings of the stockholders may be called by the Chairman of the Board of Directors, our Chief Executive Officer, our President, the Board of Directors, or in their absence or disability, by any vice president. Our Bylaws require that all stockholder actions be taken by a vote of the stockholders at an annual or special meeting, and do not permit our stockholders to act by written consent without a meeting. Our Bylaws provide for an advance notice procedure for stockholder proposals to be brought before an annual meeting of our stockholders, including proposed nominations of persons for election to the Board of Directors. At an annual meeting, stockholders may only consider proposals or nominations specified in the notice of meeting or brought before the meeting by or at the direction of the Board of Directors. The Bylaws do not give our Board of Directors the power to approve or disapprove stockholder nominations of candidates or proposals regarding other business to be conducted at a special or annual meeting of the stockholders. However, our Bylaws may have the effect of precluding the conduct of business at a meeting if the proper procedures are not followed. These provisions may also discourage or deter a potential acquirer from conducting a solicitation of proxies to elect the acquirer’s own slate of directors or otherwise attempting to obtain control of our company.

Exclusive Forum Provision 

Our certificate of incorporation provides that the Court of Chancery of the State of Delaware shall be the sole and exclusive forum for (i) any derivative action or proceeding brought our behalf, (ii) any action asserting a claim of breach of a fiduciary duty owed by any of our directors or officers to us or our stockholders, (iii) any action asserting a claim against us arising pursuant to any provision of the Delaware General Corporation Law, or our certificate of incorporation or the bylaws, and (iv) any action asserting a claim against us governed by the internal affairs doctrine. This provision would not apply to suits brought to enforce a duty or liability created by the Exchange Act or Securities Act.

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This choice of forum provision may limit a stockholder’s ability to bring a claim in a judicial forum that it finds favorable for disputes with us or our directors, officers or other employees, which may discourage such lawsuits against us and our directors, officers and employees. In addition, these provisions could increase the costs to stockholders in bringing such claims. Alternatively, a court could find these provisions of our certificate of incorporation to be inapplicable or unenforceable in respect of one or more of the specified types of actions or proceedings, which may require us to incur additional costs associated with resolving such matters in other jurisdictions, which could adversely affect our business and financial condition. 

Quotation

Our common stock is listed on The NASDAQ Capital Market and traded under the symbol “MBRX”.

Transfer Agent

The transfer agent for our common stock is VStock Transfer, LLC located at 18 Lafayette Place, Woodmere, New York 11598.

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DESCRIPTION OF PREFERRED STOCK

General

We are currently authorized to issue 5,000,000 shares of preferred stock, par value $0.001. As of the date of this prospectus, we have no shares of preferred stock outstanding.

Our Board of Directors has the authority, without action by our stockholders, to designate and issue preferred stock in one or more series. Our Board of Directors may also designate the rights, preferences and privileges of each series of preferred stock, any or all of which may be greater than the rights of the common stock. It is not possible to state the actual effect of the issuance of any shares of preferred stock on the rights of holders of the common stock until our Board of Directors determines the specific rights of the holders of the preferred stock. However, these effects might include: (a) restricting dividends on the common stock; (b) diluting the voting power of the common stock; (c) impairing the liquidation rights of the common stock; and (d) delaying or preventing a change in control of our company without further action by our stockholders.

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DESCRIPTION OF DEBT SECURITIES

General

The following description sets forth general terms that will apply to the debt securities. We will describe the particular terms of any debt securities that we offer in the prospectus supplement relating to those debt securities.

The debt securities will be either our senior debt securities or our subordinated debt securities. The senior debt securities will be issued under an indenture between us and the trustee named in the indenture. We refer to this indenture as the “senior indenture.” The subordinated debt securities will be issued under a separate Subordinated Indenture between us and the trustee named in the indenture. We refer to this indenture as the “subordinated indenture” and, together with the senior indenture, as the “indentures.” Except as permitted by applicable law, the indentures have been or will be qualified under the Trust Indenture Act of 1939.

We have filed the forms of the indentures as exhibits to the registration statement. For your convenience, we have included references to specific sections of the indentures in the descriptions below. Capitalized terms not otherwise defined in this prospectus will have the meanings given in the indenture to which they relate.

The following summaries of provisions of the debt securities and the indentures are not complete and are qualified in their entirety by reference to the provisions of the indentures and the debt securities.

Neither of the indentures limits the principal amount of debt securities that we may issue. Each indenture provides that debt securities may be issued in one or more series up to the principal amount that we may authorize from time to time. Each indenture also provides that the debt securities may be denominated in any currency or currency unit that we designate. In addition, each series of debt securities may be reopened in order to issue additional debt securities of that series in the future without the consent of the holders of debt securities of that series. Unless otherwise described in the prospectus supplement relating to a particular offering, neither the indentures nor the debt securities will contain any provisions to afford holders of any debt securities protection in the event of a takeover, recapitalization or similar restructuring of our business.

Unless otherwise described in the prospectus supplement relating to a particular offering, the senior debt securities will rank equally with all of our other unsecured and unsubordinated debt. The subordinated debt securities will be subordinated to the prior payment in full of our senior debt securities. We will describe the particular terms of the subordinated debt securities that we offer in the prospectus supplement relating to those subordinated debt securities.

We will describe the specific terms relating to each particular series of debt securities in the prospectus supplement relating to the offering of those debt securities. The terms we will describe in the prospectus supplement will include some or all of the following:

● the title and type of the debt securities;

● the total principal amount or initial offering price of the debt securities;  

● the date or dates when the principal of the debt securities will be payable;

● whether we will have the right to extend the stated maturity of the debt securities;  

● whether the debt securities will bear interest and, if so, the rate or rates, or the method for calculating the rate or rates, of interest;

● if the debt securities will bear interest, the date from which interest will accrue, the dates when interest will be payable and the regular record dates for these interest payment dates;

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● the place where the principal, premium, if any, and interest, if any, on the debt securities will be paid, registered debt securities may be surrendered for registration of transfer, and debt securities may be surrendered for exchange;  

● any sinking fund or other provisions that would obligate us to repurchase or otherwise redeem the debt securities;

● the terms and conditions upon which we will have the option or the obligation to redeem the debt securities;

● the denominations in which any registered debt securities will be issuable;

● the identity of each security registrar and paying agent, and the designation of the exchange rate agent, if any, if other than the trustee;

● the portion of the principal amount of debt securities that will be payable upon acceleration of the maturity of the debt securities;

● the currency used to pay principal, premium, if any, and interest, if any, on the debt securities, if other than U.S. dollars, and whether you or we may elect to have principal, premium and interest paid in a currency other than the currency in which the debt securities are denominated;

● any index, formula or other method used to determine the amount of principal, premium or interest on the debt securities;

● any changes or additions to the events of default, defaults or our covenants made in the applicable indenture;

● whether the debt securities are issuable as registered debt securities or bearer debt securities, whether there are any restrictions relating to the form in which they are issued and whether bearer and registered debt securities may be exchanged for each other;

● to whom interest will be payable

o if other than the registered holder (for registered debt securities),

o if other than upon presentation and surrender of the related coupons (for bearer debt securities), or

o if other than as specified in the indentures (for global debt securities);

● whether the debt securities are to be convertible or exchangeable for other securities and, if so, the terms of conversion or exchange;

● particular terms of subordination with respect to subordinated debt securities; and

● any other terms of the debt securities consistent with the provisions of the applicable indenture.

We may issue debt securities as original issue discount securities to be sold at a substantial discount below their principal amount. If we issue original issue discount securities, then we will describe the material U.S. federal income tax consequences that apply to those debt securities in the applicable prospectus supplement.

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Registration and Transfer

We presently plan to issue each series of debt securities only as registered securities. However, we may issue a series of debt securities as bearer securities, or a combination of both registered securities and bearer securities. If we issue senior debt securities as bearer securities, they will have interest coupons attached unless we elect to issue them as zero coupon securities. If we issue bearer securities, we may describe material U.S. federal income tax consequences and other material considerations, procedures and limitations in the applicable prospectus supplement.

Holders of registered debt securities may present the debt securities for exchange for different authorized amounts of other debt securities of the same series and in the same aggregate principal amount at the corporate trust office of the trustee or at the office of any other transfer agent we may designate for the purpose and describe in the applicable prospectus supplement. The registered securities must be duly endorsed or accompanied by a written instrument of transfer. The agent will not impose a service charge on you for the transfer or exchange. We may, however, require that you pay any applicable tax or other governmental charge. If we issue bearer securities, we will describe any procedures for exchanging those bearer securities for other senior debt securities of the same series in the applicable prospectus supplement. Generally, we will not allow you to exchange registered securities for bearer securities.

In general, unless otherwise specified in the applicable prospectus supplement, we will issue registered securities without coupons and in denominations of $1,000 or integral multiples, and bearer securities in denominations of $5,000. We may issue both registered and bearer securities in global form.

Conversion and Exchange

If any debt securities will be convertible into or exchangeable for our common stock, preferred stock or other securities, the applicable prospectus supplement will set forth the terms and conditions of the conversion or exchange, including:

● the conversion price or exchange ratio; 

● the conversion or exchange period;

● whether the conversion or exchange will be mandatory or at the option of the holder or us;

● provisions for adjustment of the conversion price or exchange ratio; and

● provisions that may affect the conversion or exchange if the debt securities are redeemed.

Redemption

Unless otherwise indicated in the applicable prospectus supplement, we may, at our option, redeem any series of debt securities in whole at any time or in part from time to time. If any series of debt securities are redeemable only on or after a certain date or only upon satisfaction of additional conditions, the applicable prospectus supplement will specify the date or the additional conditions. Unless otherwise specified in the applicable prospectus supplement, the redemption price for debt securities will equal 100% of the principal amount plus any accrued and unpaid interest on those debt securities.

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The applicable prospectus supplement will contain the specific terms on which we may redeem a series of debt securities prior to its stated maturity. Unless otherwise described in the prospectus supplement relating to a particular offering, we will send a notice of redemption to holders at least 30 days but not more than 60 days prior to the redemption date. The notice will state:

● the redemption date;

● the redemption price;

● if less than all of the debt securities of the series are being redeemed, the particular debt securities to be redeemed (and the principal amounts, in the case of a partial redemption);

● that on the redemption date, the redemption price will become due and payable and any applicable interest will cease to accrue on and after that date;

● the place or places of payment;

● whether the redemption is for a sinking fund; and

● any other provisions required by the terms of the debt securities of the series that are being redeemed.

On or before any redemption date, we will deposit an amount of money with the trustee or with a paying agent sufficient to pay the redemption price.

Unless otherwise described in the prospectus supplement relating to a particular offering, if we are redeeming less than all the debt securities, the trustee will select the debt securities to be redeemed using a method it considers fair and appropriate. After the redemption date, holders of redeemed debt securities will have no rights with respect to the debt securities except the right to receive the redemption price and any unpaid interest to the redemption date.

Events of Default

Unless otherwise described in the prospectus supplement relating to a particular offering, an “event of default” regarding any series of debt securities is any one of the following events:

● default for 30 days in the payment of any interest installment when due and payable;

● default in the making of any sinking fund payment when due;

● default in the payment of principal or premium (if any) when due at its stated maturity, by declaration, when called for redemption or otherwise;

● default in the performance of any covenant in the debt securities of that series or in the applicable indenture for 60 days after notice to us by the trustee or by the holders of 25% in principal amount of the outstanding debt securities of that series;

● certain events of bankruptcy, insolvency and reorganization; and

● any other event of default provided with respect to that series of debt securities.

We are required to file every year with each trustee an officers’ certificate stating whether any default exists and specifying any default that exists.

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Acceleration of Maturity

Unless otherwise described in the prospectus supplement relating to a particular offering, if an event of default has occurred and is continuing with respect to debt securities of a particular series (except, in the case of subordinated debt securities, defaults relating to bankruptcy events), the trustee or the holders of not less than 25% in principal amount of outstanding debt securities of that series may declare the principal amount of outstanding debt securities of that series due and payable immediately.

Unless otherwise described in the prospectus supplement relating to a particular offering, at any time after a declaration of acceleration of maturity with respect to debt securities of any series has been made and before a judgment or decree for payment of the money due has been obtained by the trustee, the holders of a majority in principal amount of the outstanding debt securities of that series by written notice to us and the trustee, may rescind and annul the declaration and its consequences if:

● we have paid or deposited with the trustee a sum sufficient to pay:

o all overdue interest on all outstanding debt securities of that series and any related coupons,

o all unpaid principal of and premium, if any, on any of the debt securities which has become due otherwise than by the declaration of acceleration, and interest on the unpaid principal at the rate or rates prescribed in the debt securities,

o to the extent lawful, interest on overdue interest at the rate or rates prescribed in the debt securities, and

o all sums paid or advanced by the trustee and the reasonable compensation, expenses, disbursements and advances of the trustee, its agents and counsel; and

● all events of default with respect to debt securities of that series, other than the non-payment of amounts of principal, interest or any premium on the debt securities which have become due solely by the declaration of acceleration, have been cured or waived.

No rescission will affect any subsequent default or impair any right consequent thereon.

Waiver of Defaults

Unless otherwise described in the prospectus supplement relating to a particular offering, the holders of not less than a majority in principal amount of the outstanding debt securities of any series may, on behalf of the holders of all the debt securities of the series and any related coupons, waive any past default under the applicable indenture with respect to the series and its consequences, except a default:

● in the payment of the principal of or premium, if any, or interest on any debt security of the series or any related coupon, or

● in respect of a covenant or provision that cannot be modified or amended without the consent of the holder of each outstanding debt security of the series affected thereby.

If an event of default with respect to debt securities of a particular series occurs and is continuing, the trustee will not be obligated to exercise any of its rights or powers under the applicable indenture at the request or direction of any of the holders of debt securities of the series, unless the holders have offered to the trustee reasonable indemnity and security against the costs, expenses and liabilities that might be incurred by it in compliance with the request.

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The holders of a majority in principal amount of the outstanding debt securities of any series have the right to direct the time, method and place of conducting any proceeding for any remedy available to the trustee under the applicable indenture, or exercising any trust or power conferred on the trustee with respect to the debt securities of that series. The trustee may refuse to follow directions in conflict with law or the indenture that may expose the trustee to personal liability or may be unduly prejudicial to the other, non-directing holders. Additionally, the trustee may take any other action the trustee deems proper which is not inconsistent with the direction.

Modification of Indenture

We and the trustee may, without the consent of any holders of debt securities, enter into supplemental indentures for various purposes, including:

● to evidence the succession of another entity to us and the assumption by the successor of our covenants and obligations under the debt securities and the indenture;

● establishing the form or terms of any series of debt securities issued under the supplemental indentures;

● adding to our covenants for the benefit of the holders or to surrender any of our rights or powers under the indenture;

● adding additional events of default for the benefit of the holders;

● to change or eliminate any provisions of the indenture provided that the change or elimination becomes effective only when there is no debt security outstanding entitled to the benefit of any changed or eliminated provision;

● to secure the debt securities;

● to cure any ambiguities or correct defective or inconsistent provisions of the indenture, provided that holders of debt securities are not materially affected by the change;

● to evidence and provide for acceptance of a successor trustee; and

● to comply with the requirements of the Trust Indenture Act.

We and the trustee may, with the consent of the holders of not less than a majority in principal amount of the outstanding debt securities of all affected series acting as one class, execute supplemental indentures adding any provisions to or changing or eliminating any of the provisions of the indenture or modifying the rights of the holders of the debt securities of the series. Without the consent of the holders of all the outstanding debt securities affected thereby, no supplemental indenture may:

● change the stated maturity of the principal of, or any installment of principal of or interest on, any debt security;

● reduce the principal amount of, the rate of interest on or any premium payable upon the redemption of, or change the manner of calculating the rate of interest on, any debt security;

● reduce the amount of the principal of any original issue discount security that would be due and payable upon acceleration of the maturity of the debt security;

● change the place of payment where, or the currency in which, principal or interest on any debt security is payable;

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● impair the right to institute suit for enforcement of payments;

● reduce the percentage in principal amount of the outstanding debt securities of any series, the holders of which must consent to a supplemental indenture or any waiver of compliance with various provisions of, or defaults and covenants under, the indenture; or

● modify any of the provisions described in this section.

Consolidation, Merger and Sale of Assets

Unless otherwise described in the prospectus supplement relating to a particular offering, as provided in the indentures, we may not consolidate with or merge into any other person, or convey, transfer or lease all or substantially all of our assets to any other person, unless:

● the person surviving or formed by the transaction is organized and validly existing under the laws of any United States jurisdiction and expressly assumes our obligations under the debt securities and the indentures;

● immediately after giving effect to the transaction, no event of default will have occurred and be continuing under the indentures; and

● the trustees under the indentures receive certain officers’ certificates and opinions of counsel.

Satisfaction and Discharge

We may terminate our obligations with respect to debt securities of any series not previously delivered to the trustee for cancellation when those debt securities:

● have become due and payable;  

● will become due and payable at their stated maturity within one year; or

● are to be called for redemption within one year under arrangements satisfactory to the indenture trustee for giving notice of redemption.

We may terminate our obligations with respect to the debt securities of a series by depositing with the trustee, as trust funds in trust dedicated solely for that purpose, an amount sufficient to pay and discharge the entire indebtedness on the debt securities of that series. In that case, the applicable indenture will cease to be of further effect, and our obligations will be satisfied and discharged with respect to that series (except our obligations to pay all other amounts due under the indenture and to provide certain officers’ certificates and opinions of counsel to the trustee). At our expense, the trustee will execute proper instruments acknowledging the satisfaction and discharge.

The Trustees

Any trustee may be deemed to have a conflicting interest for purposes of the Trust Indenture Act and may be required to resign as trustee if there is an event of default under the applicable indenture and, as more fully described in Section 310(b) of the Trust Indenture Act, one or more of the following occurs:

● the trustee is a trustee under another indenture under which our securities are outstanding;

● the trustee is a trustee for more than one outstanding series of debt securities under a single indenture;

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● we or our affiliates or underwriters hold certain threshold ownership beneficial ownership interest in the trustee;

● the trustee holds certain threshold beneficial ownership interests in us or in securities of ours that are in default;

● the trustee is one of our creditors; or

● the trustee or one of its affiliates acts as an underwriter or agent for us.

We may appoint an alternative trustee for any series of debt securities. The appointment of an alternative trustee would be described in the applicable prospectus supplement.

We and our affiliates may engage in transactions with the trustee and its affiliates in the ordinary course of business.

Governing Law

Each of the indentures are, and the related senior debt securities and subordinated debt securities will be, governed by and construed under the internal laws of the State of New York.

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DESCRIPTION OF THE WARRANTS

We may issue warrants to purchase debt securities, preferred stock or common stock. We may offer warrants separately or together with one or more additional warrants, debt securities, shares of preferred stock or common stock, or any combination of those securities in the form of units, as described in the applicable prospectus supplement. If we issue warrants as part of a unit, the prospectus supplement will specify whether those warrants may be separated from the other securities in the unit prior to the warrants’ expiration date. We may issue the warrants under warrant agreements to be entered into between us and a bank or trust company, as warrant agent, all as described in the prospectus supplement. If we issue the warrants under warrant agreements, the warrant agent will act solely as our agent in connection with the warrants and will not assume any obligation or relationship of agency or trust for or with any holders or beneficial owners of warrants.

We will describe the particular terms of any warrants that we offer in the prospectus supplement relating to those warrants. Those terms may include the following:

● the specific designation and aggregate number of warrants, and the price at which we will issue the warrants;

● the currency or currency units in which the offering price, if any, and the exercise price are payable;

● the date on which the right to exercise the warrants will begin and the date on which the right will expire or, if the warrants are not continuously exercisable throughout that period, the specific date or dates on which they are exercisable;

● whether the warrants will be issued in fully registered form or bearer form, in definitive or global form or in any combination of these forms;

● any applicable material United States federal income tax considerations;

● the identity of the warrant agent, if any, for the warrants and of any other depositaries, execution or paying agents, transfer agents, registrars or other agents;

● the designation, aggregate principal amount, currency, denomination and terms of any debt securities that may be purchased upon exercise of the warrants;

● the designation, amount, currency, denominations and terms of any preferred stock or common stock purchasable upon exercise of the warrants;

● if applicable, the designation and terms of the debt securities, preferred stock or common stock with which the warrants are issued and the number of warrants issued with each security;

● if applicable, the date from and after which the warrants and the related debt securities, preferred stock or common stock will be separately transferable;

● the principal amount of debt securities or the number of shares of preferred stock or common stock purchasable upon exercise of any warrant and the price at which those shares may be purchased;

● provisions for changes to or adjustments in the exercise price;

● if applicable, the minimum or maximum number of warrants that may be exercised at any one time;

● information with respect to any book-entry procedures;

● any antidilution provision of the warrants;

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● any redemption or call provisions; and

● any additional terms of the warrants, including terms, procedures and limitations relating to the exchange and exercise of the warrants.

Each warrant will entitle the holder thereof to purchase such number of shares of common stock or preferred stock or other securities at the exercise price as will in each case be set forth in, or be determinable as set forth in, the applicable prospectus supplement. Warrants may be exercised at any time up to the close of business on the expiration date set forth in the applicable prospectus supplement. After the close of business on the expiration date, unexercised warrants will become void. Warrants may be exercised as set forth in the applicable prospectus supplement relating to the warrants offered thereby. Upon receipt of payment and the warrant certificate properly completed and duly executed at the corporate trust office of the warrant agent or any other office indicated in the applicable prospectus supplement, we will, as soon as practicable, forward the purchased securities. If less than all of the warrants represented by the warrant certificate are exercised, a new warrant certificate will be issued for the remaining warrants.

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DESCRIPTION OF UNITS

We may issue, in one or more series, units comprised of shares of our common stock or preferred stock, warrants to purchase common stock or preferred stock, debt securities or any combination of those securities. Each unit will be issued so that the holder of the unit is also the holder of each security included in the unit. Thus, the holder of a unit will have the rights and obligations of a holder of each included security.

We may evidence units by unit certificates that we issue under a separate agreement. We may issue the units under a unit agreement between us and one or more unit agents. If we elect to enter into a unit agreement with a unit agent, the unit agent will act solely as our agent in connection with the units and will not assume any obligation or relationship of agency or trust for or with any registered holders of units or beneficial owners of units. We will indicate the name and address and other information regarding the unit agent in the applicable prospectus supplement relating to a particular series of units if we elect to use a unit agent.

We will describe in the applicable prospectus supplement the terms of the series of units being offered, including: (i) the designation and terms of the units and of the securities comprising the units, including whether and under what circumstances those securities may be held or transferred separately; (ii) any provisions of the governing unit agreement that differ from those described herein; and (iii) any provisions for the issuance, payment, settlement, transfer or exchange of the units or of the securities comprising the units.

The other provisions regarding our common stock, preferred stock, warrants and debt securities as described in this section will apply to each unit to the extent such unit consists of shares of our common stock, preferred stock, warrants and/or debt securities.

PLAN OF DISTRIBUTION

We may sell the securities covered by this prospectus in one or more of the following ways from time to time:

● to or through underwriters or dealers for resale to the purchasers;

● directly to purchasers;

● through agents or dealers to the purchasers; or

● through a combination of any of these methods of sale.

In addition, we may enter into derivative or other hedging transactions with third parties, or sell securities not covered by this prospectus to third parties in privately negotiated transactions. The applicable prospectus supplement may indicate that third parties may sell securities covered by this prospectus and the prospectus supplement, including in short sale transactions, in connection with those derivatives. If so, the third party may use securities we pledge or that are borrowed from us or others to settle those sales or to close out any related open borrowings of stock, and may use securities received from us in settlement of those derivatives to close out any related open borrowings of stock. The third party in those sale transactions will be an underwriter and, if applicable, will be identified in the prospectus supplement (or a post-effective amendment thereto).

A prospectus supplement with respect to each series of securities will include, to the extent applicable:

● the terms of the offering;

● the name or names of any underwriters, dealers, remarketing firms, or agents and the terms of any agreement with those parties, including the compensation, fees, or commissions received by, and the amount of securities underwritten, purchased, or remarketed by, each of them, if any;

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● the public offering price or purchase price of the securities and an estimate of the net proceeds to be received by us from any such sale, as applicable;

● any underwriting discounts or agency fees and other items constituting underwriters’ or agents’ compensation;

● the anticipated delivery date of the securities, including any delayed delivery arrangements, and any commissions we may pay for solicitation of any such delayed delivery contracts;

● that the securities are being solicited and offered directly to institutional investors or others;

● any discounts or concessions to be allowed or reallowed or to be paid to agents or dealers; and

● any securities exchange on which the securities may be listed.

Any offer and sale of the securities described in this prospectus by us, any underwriters, or other third parties described above may be effected from time to time in one or more transactions, including, without limitation, privately negotiated transactions, either:

● at a fixed public offering price or prices, which may be changed;

● at market prices prevailing at the time of sale;

● at prices related to prevailing market prices at the time of sale; or

● at negotiated prices.

Offerings of securities covered by this prospectus also may be made into an existing trading market for those securities in transactions at other than a fixed price, either:

● on or through the facilities of the NASDAQ Capital Market or any other securities exchange or quotation or trading service on which those securities may be listed, quoted, or traded at the time of sale; and/or

● to or through a market maker otherwise than on the NASDAQ Capital Market or those other securities exchanges or quotation or trading services.

Those at-the-market offerings, if any, will be conducted by underwriters acting as our principal or agent, who may also be third-party sellers of securities as described above.

In addition, we may sell some or all of the securities covered by this prospectus through:

● purchases by a dealer, as principal, who may then resell those securities to the public for its account at varying prices determined by the dealer at the time of resale or at a fixed price agreed to with us at the time of sale;

● block trades in which a dealer will attempt to sell as agent, but may position or resell a portion of the block as principal in order to facilitate the transaction; and/or

● ordinary brokerage transactions and transactions in which a broker-dealer solicits purchasers.

Any dealer may be deemed to be an underwriter, as that term is defined in the Securities Act of 1933 of the securities so offered and sold.

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In connection with offerings made through underwriters or agents, we may enter into agreements with those underwriters or agents pursuant to which we receive our outstanding securities in consideration for the securities being offered to the public for cash. In connection with these arrangements, the underwriters or agents also may sell securities covered by this prospectus to hedge their positions in any such outstanding securities, including in short sale transactions. If so, the underwriters or agents may use the securities received from us under those arrangements to close out any related open borrowings of securities.

We may loan or pledge securities to a financial institution or other third party that in turn may sell the loaned securities or, in any event of default in the case of a pledge, sell the pledged securities using this prospectus and the applicable prospectus supplement. That financial institution or third party may transfer its short position to investors in our securities or in connection with a simultaneous offering of other securities covered by this prospectus.

We may solicit offers to purchase the securities covered by this prospectus directly from, and we may make sales of such securities directly to, institutional investors or others, who may be deemed to be underwriters within the meaning of the Securities Act with respect to any resale of such securities.

The securities may also be offered and sold, if so indicated in a prospectus supplement, in connection with a remarketing upon their purchase, in accordance with a redemption or repayment pursuant to their terms, or otherwise, by one or more remarketing firms acting as principals for their own accounts or as agents for us.

If indicated in the applicable prospectus supplement, we may sell the securities through agents from time to time. We generally expect that any agent will be acting on a “best efforts” basis for the period of its appointment.

If underwriters are used in any sale of any securities, the securities may be either offered to the public through underwriting syndicates represented by managing underwriters, or directly by underwriters. Unless otherwise stated in a prospectus supplement, the obligations of the underwriters to purchase any securities will be conditioned on customary closing conditions, and the underwriters will be obligated to purchase all of that series of securities, if any are purchased.

Underwriters, dealers, agents, and remarketing firms may at the time of any offering of securities be entitled under agreements entered into with us to indemnification by us against certain civil liabilities, including liabilities under the Securities Act, or to contribution with respect to payments that the underwriters, dealers, agents, and remarketing firms may be required to make. Underwriters, dealers, agents, and remarketing agents may be customers of, engage in transactions with, or perform services in the ordinary course of business for us and/or our affiliates.

Any underwriters to whom securities covered by this prospectus are sold by us for public offering and sale, if any, may make a market in the securities, but those underwriters will not be obligated to do so and may discontinue any market making at any time without notice.

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LEGAL MATTERS

Schiff Hardin LLP, Washington, DC, will pass upon the validity of the securities offered by this prospectus for us. Legal matters will be passed upon for any underwriters, dealers or agents by counsel named in the applicable prospectus supplement.

EXPERTS

The audited financial statements incorporated by reference in this prospectus and elsewhere in the registration statement have been so incorporated by reference in reliance upon the report of Grant Thornton LLP, independent registered public accountants, upon the authority of said firms as experts in accounting and auditing.

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Shares

Common Stock

Pre-Funded Warrants to Purchase Shares of Common Stock

 

PROSPECTUS SUPPLEMENT

                  , 2021

Sole Book-Running Manager

Oppenheimer & Co.