Organization and Description of the Business	6 Months Ended
Jun. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of the Business	1. Organization and Description of the Business Description of Business Apexigen, Inc. (“Apexigen” or “we”) is a clinical-stage biopharmaceutical company focused on discovering and developing antibody therapeutics for oncology, with an emphasis on new immuno-oncology agents designed to harness the patient’s immune system to combat and eradicate cancer. Our lead product candidates are sotigalimab (“sotiga” or “APX005M”), which is a CD40 agonist antibody, and APX601, which is a TNFR2 antagonist antibody. We also have out-license arrangements for a number of programs. Since inception, we have devoted substantially all of our resources to performing research, development, and manufacturing activities in support of our product candidates. In October 2019, the first of our out-licensed product candidates was approved for commercial product sale. Apexigen is headquartered in San Carlos, California. In March 2022, Brookline Capital Acquisition Corp. (“BCAC”) and Apexigen America, Inc., which was then known as Apexigen, Inc. (“Legacy Apexigen”), entered into a business combination agreement (“Brookline Business Combination Agreement”) pursuant to which BCAC and Legacy Apexigen agreed to combine, with Legacy Apexigen’s equityholders owning a majority of the equity in the combined public company. The transactions contemplated under the Brookline Business Combination Agreement (the “Brookline Merger”) closed in July 2022. At that time, a subsidiary of BCAC merged with and into Legacy Apexigen with Legacy Apexigen surviving the merger as a wholly owned subsidiary of BCAC. Additionally, BCAC changed its name to Apexigen, Inc. and Legacy Apexigen changed its name to Apexigen America, Inc. Legacy Apexigen was incorporated in Delaware in 2010, the year Legacy Apexigen was spun-out of Epitomics, Inc. (“Epitomics”), which was a California-based biotechnology company that was acquired by Abcam plc in 2012. Legacy Apexigen was spun-out of Epitomics to focus on the discovery, development, and commercialization of humanized monoclonal antibody therapeutics. Liquidity, Capital Resources, and Recent Developments On February 27, 2023, we announced that we were implementing a corporate restructuring to extend our cash runway as we reviewed and explored strategic alternatives. As part of the restructuring, which was approved by our board of directors on February 23, 2023, we announced plans to reduce the size of our workforce by 55%, impacting up to 11 of our 20 employee positions. We eliminated nine employee positions as of June 30, 2023 and do not expect to eliminate any additional positions prior to the completion of the merger with Pyxis Oncology, Inc. As a result of the restructuring, we incurred severance costs of $0.1 million and $0.4 million during the three and six months ended June 30, 2023, respectively. On April 11, 2023, we received a written notice from the Listing Qualifications Staff of the Nasdaq Stock Market (“Nasdaq”) notifying the Company that it has not been in compliance with the minimum bid price requirement set forth in Nasdaq Listing Rule 5450(a)(1) for a period of 30 consecutive business days (the “Notice”). This Notice has no immediate effect on the listing of our stock on the Nasdaq Capital Market. In accordance with Nasdaq Listing Rule 5810(c)(3)(A), we have a compliance period of 180 calendar days from the date of the Notice to regain compliance with the minimum closing bid price requirement. If we do not regain compliance during the compliance period, we may be afforded a second 180 calendar day period to regain compliance. To qualify, we must meet the continued listing requirement for market value of publicly-held shares and all other initial listing standards for the Nasdaq Capital Market (with the exception of the minimum bid price requirement) and notify Nasdaq of our intent to cure the deficiency by effecting a reverse stock split if necessary. If we do not regain compliance within the allotted compliance periods, including any extensions that may be granted by Nasdaq, our stock will be subject to delisting. We can achieve compliance with the minimum bid price requirement if, during either compliance period, the closing bid price per share of our stock is at least $1.00 for a minimum of ten consecutive business days. We intend to monitor the closing bid price of our stock and assess potential actions to regain compliance, but there can be no assurance that we will regain compliance with the minimum bid price requirement during the 180-day compliance period, secure a second 180-day period to regain compliance, or maintain compliance with the other Nasdaq listing requirements. On May 23, 2023, we entered into an Agreement and Plan of Merger (the “Pyxis Merger Agreement”) with Pyxis Oncology, Inc. (“Pyxis Oncology”) and Ascent Merger Sub Corp., a wholly owned subsidiary of Pyxis Oncology (“Merger Sub”), pursuant to which Merger Sub will merge with and into Apexigen (the “Pyxis Merger”), with Apexigen surviving such merger as a wholly owned subsidiary of Pyxis Oncology. The Pyxis Merger is intended to qualify as a tax-free reorganization for U.S. federal income tax purposes. On June 30, 2023, we filed a definitive merger proxy statement announcing a special meeting of Apexigen stockholders to be held virtually on August 22, 2023. Holders of our common stock as of the close of business on June 28, 2023 (the “Record Date”) are entitled to vote at the special meeting. The completion of the Pyxis Merger is subject to the satisfaction or waiver of certain closing conditions, including the approval of the adoption of the Pyxis Merger Agreement by a majority of our outstanding shares of common stock as of the Record Date. At the closing of the Pyxis Merger, each outstanding share of our common stock will automatically convert into the right to receive 0.1725 (the “Exchange Ratio”) shares of common stock of Pyxis Oncology. As of June 30, 2023, we had approximately $9.4 million of cash and cash equivalents, and expect to fund our operations into the fourth quarter of 2023 based on current operations assuming no additional proceeds from our equity line agreement with Lincoln Park Capital Fund, LLC (“Lincoln Park”) or any other potential financing or business development transactions. We have incurred substantial losses and negative cash flows from operations since inception and had an accumulated deficit of $188.9 million as of June 30, 2023. Since inception through June 30, 2023, we have funded operations primarily through the issuance of equity, proceeds from collaborative research and development agreements, and borrowings under a debt arrangement. Due to our significant research, development, and manufacturing expenditures, we have generated operating losses in all periods presented. We expect to incur substantial additional losses in the future as we advance and expand our research and development activities and prepare to pursue the potential regulatory approval and commercialization of our product candidates. Based on our research and development activities and plans, there is uncertainty regarding our ability to maintain liquidity sufficient to operate the business effectively, which raises substantial doubt as to our ability to continue as a going concern. We may seek additional funds through the sale and issuance of shares of our common stock in private or public offerings, other equity or debt financings, collaborations, or partnerships with third parties, or other transactions to monetize assets, including our right to receive milestone payments and royalties under our out-license arrangements. We cannot assure that we will succeed in acquiring additional funding at levels sufficient to fund our operations or on terms favorable to us. If we are unable to obtain adequate financing when needed, we may have to delay, reduce the scope of or suspend one or more of our clinical trials or preclinical studies or research and development programs. Because of the numerous risks and uncertainties associated with the development and commercialization of our product candidates, we are unable to estimate the amount of increased capital outlays and operating expenditures associated with our current and planned research, development, and manufacturing activities. To the extent that we raise additional capital through strategic alliances, licensing arrangements or other monetization transactions with third parties, we may have to relinquish valuable rights to our product candidates, future revenue streams or research programs or grant licenses on terms that may not be favorable to us. If we raise additional capital through public or private equity offerings, the ownership interest of the then-existing stockholders will be diluted, and the terms of these securities may include liquidation or other preferences that adversely affect our stockholders’ rights. If we raise additional capital through debt financing, we may be subject to covenants limiting or restricting the ability to take specific actions, such as incurring additional debt, making capital expenditures, or declaring dividends.

Organization and Description of the Business

6 Months Ended

Jun. 30, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Organization and Description of the Business

1. Organization and Description of the Business

Description of Business

Apexigen, Inc. (“Apexigen” or “we”) is a clinical-stage biopharmaceutical company focused on discovering and developing antibody therapeutics for oncology, with an emphasis on new immuno-oncology agents designed to harness the patient’s immune system to combat and eradicate cancer. Our lead product candidates are sotigalimab (“sotiga” or “APX005M”), which is a CD40 agonist antibody, and APX601, which is a TNFR2 antagonist antibody. We also have out-license arrangements for a number of programs. Since inception, we have devoted substantially all of our resources to performing research, development, and manufacturing activities in support of our product candidates. In October 2019, the first of our out-licensed product candidates was approved for commercial product sale. Apexigen is headquartered in San Carlos, California.

In March 2022, Brookline Capital Acquisition Corp. (“BCAC”) and Apexigen America, Inc., which was then known as Apexigen, Inc. (“Legacy Apexigen”), entered into a business combination agreement (“Brookline Business Combination Agreement”) pursuant to which BCAC and Legacy Apexigen agreed to combine, with Legacy Apexigen’s equityholders owning a majority of the equity in the combined public company. The transactions contemplated under the Brookline Business Combination Agreement (the “Brookline Merger”) closed in July 2022. At that time, a subsidiary of BCAC merged with and into Legacy Apexigen with Legacy Apexigen surviving the merger as a wholly owned subsidiary of BCAC. Additionally, BCAC changed its name to Apexigen, Inc. and Legacy Apexigen changed its name to Apexigen America, Inc.

Legacy Apexigen was incorporated in Delaware in 2010, the year Legacy Apexigen was spun-out of Epitomics, Inc. (“Epitomics”), which was a California-based biotechnology company that was acquired by Abcam plc in 2012. Legacy Apexigen was spun-out of Epitomics to focus on the discovery, development, and commercialization of humanized monoclonal antibody therapeutics.

Liquidity, Capital Resources, and Recent Developments

On February 27, 2023, we announced that we were implementing a corporate restructuring to extend our cash runway as we reviewed and explored strategic alternatives. As part of the restructuring, which was approved by our board of directors on February 23, 2023, we announced plans to reduce the size of our workforce by 55%, impacting up to 11 of our 20 employee positions. We eliminated nine employee positions as of June 30, 2023 and do not expect to eliminate any additional positions prior to the completion of the merger with Pyxis Oncology, Inc. As a result of the restructuring, we incurred severance costs of $0.1 million and $0.4 million during the three and six months ended June 30, 2023, respectively.

On April 11, 2023, we received a written notice from the Listing Qualifications Staff of the Nasdaq Stock Market (“Nasdaq”) notifying the Company that it has not been in compliance with the minimum bid price requirement set forth in Nasdaq Listing Rule 5450(a)(1) for a period of 30 consecutive business days (the “Notice”). This Notice has no immediate effect on the listing of our stock on the Nasdaq Capital Market.

In accordance with Nasdaq Listing Rule 5810(c)(3)(A), we have a compliance period of 180 calendar days from the date of the Notice to regain compliance with the minimum closing bid price requirement. If we do not regain compliance during the compliance period, we may be afforded a second 180 calendar day period to regain compliance. To qualify, we must meet the continued listing requirement for market value of publicly-held shares and all other initial listing standards for the Nasdaq Capital Market (with the exception of the minimum bid price requirement) and notify Nasdaq of our intent to cure the deficiency by effecting a reverse stock split if necessary. If we do not regain compliance within the allotted compliance periods, including any extensions that may be granted by Nasdaq, our stock will be subject to delisting.

We can achieve compliance with the minimum bid price requirement if, during either compliance period, the closing bid price per share of our stock is at least $1.00 for a minimum of ten consecutive business days.

We intend to monitor the closing bid price of our stock and assess potential actions to regain compliance, but there can be no assurance that we will regain compliance with the minimum bid price requirement during the 180-day compliance period, secure a second 180-day period to regain compliance, or maintain compliance with the other Nasdaq listing requirements.

On May 23, 2023, we entered into an Agreement and Plan of Merger (the “Pyxis Merger Agreement”) with Pyxis Oncology, Inc. (“Pyxis Oncology”) and Ascent Merger Sub Corp., a wholly owned subsidiary of Pyxis Oncology (“Merger Sub”), pursuant to which Merger Sub will merge with and into Apexigen (the “Pyxis Merger”), with Apexigen surviving such merger as a wholly owned

subsidiary of Pyxis Oncology. The Pyxis Merger is intended to qualify as a tax-free reorganization for U.S. federal income tax purposes. On June 30, 2023, we filed a definitive merger proxy statement announcing a special meeting of Apexigen stockholders to be held virtually on August 22, 2023. Holders of our common stock as of the close of business on June 28, 2023 (the “Record Date”) are entitled to vote at the special meeting. The completion of the Pyxis Merger is subject to the satisfaction or waiver of certain closing conditions, including the approval of the adoption of the Pyxis Merger Agreement by a majority of our outstanding shares of common stock as of the Record Date. At the closing of the Pyxis Merger, each outstanding share of our common stock will automatically convert into the right to receive 0.1725 (the “Exchange Ratio”) shares of common stock of Pyxis Oncology.

As of June 30, 2023, we had approximately $9.4 million of cash and cash equivalents, and expect to fund our operations into the fourth quarter of 2023 based on current operations assuming no additional proceeds from our equity line agreement with Lincoln Park Capital Fund, LLC (“Lincoln Park”) or any other potential financing or business development transactions. We have incurred substantial losses and negative cash flows from operations since inception and had an accumulated deficit of $188.9 million as of June 30, 2023. Since inception through June 30, 2023, we have funded operations primarily through the issuance of equity, proceeds from collaborative research and development agreements, and borrowings under a debt arrangement. Due to our significant research, development, and manufacturing expenditures, we have generated operating losses in all periods presented. We expect to incur substantial additional losses in the future as we advance and expand our research and development activities and prepare to pursue the potential regulatory approval and commercialization of our product candidates. Based on our research and development activities and plans, there is uncertainty regarding our ability to maintain liquidity sufficient to operate the business effectively, which raises substantial doubt as to our ability to continue as a going concern.

We may seek additional funds through the sale and issuance of shares of our common stock in private or public offerings, other equity or debt financings, collaborations, or partnerships with third parties, or other transactions to monetize assets, including our right to receive milestone payments and royalties under our out-license arrangements. We cannot assure that we will succeed in acquiring additional funding at levels sufficient to fund our operations or on terms favorable to us. If we are unable to obtain adequate financing when needed, we may have to delay, reduce the scope of or suspend one or more of our clinical trials or preclinical studies or research and development programs. Because of the numerous risks and uncertainties associated with the development and commercialization of our product candidates, we are unable to estimate the amount of increased capital outlays and operating expenditures associated with our current and planned research, development, and manufacturing activities.

To the extent that we raise additional capital through strategic alliances, licensing arrangements or other monetization transactions with third parties, we may have to relinquish valuable rights to our product candidates, future revenue streams or research programs or grant licenses on terms that may not be favorable to us. If we raise additional capital through public or private equity offerings, the ownership interest of the then-existing stockholders will be diluted, and the terms of these securities may include liquidation or other preferences that adversely affect our stockholders’ rights. If we raise additional capital through debt financing, we may be subject to covenants limiting or restricting the ability to take specific actions, such as incurring additional debt, making capital expenditures, or declaring dividends.