Exhibit 10.23

FIRST AMENDMENT TO
LOAN AND SECURITY AGREEMENT

THIS FIRST AMENDMENT to Loan and Security Agreement (this “Amendment”) is entered into as of December 18, 2020 (the “Amendment Date”), by and among OXFORD FINANCE LLC, a Delaware limited liability company with an office located at 133 North Fairfax Street, Alexandria, Virginia 22314 (“Oxford”), as collateral agent (in such capacity, “Collateral Agent”), the Lenders listed on Schedule 1.1 to the Loan Agreement (as defined below) or otherwise a party thereto from time to time including Oxford in its capacity as a Lender and SILICON VALLEY BANK, a California corporation with an office located at 3003 Tasman Drive, Santa Clara, California 95054 (“Bank” or “SVB”) (each a “Lender” and collectively, the “Lenders”), and EQUILLIUM, INC., a Delaware corporation with offices located at 2223 Avenida de la Playa, Suite 108, La Jolla, California 92037 (“Borrower”).

Recitals

A. Collateral Agent, Borrower and Lenders have entered into that certain Loan and Security Agreement, dated as of September 30, 2019 (as amended, supplemented or otherwise modified from time to time, the “Loan Agreement”) pursuant to which Lenders have provided to Borrower certain loans in accordance with the terms and conditions thereof.

B. Lenders have extended credit to Borrower for the purposes permitted in the Loan Agreement.

C. Borrower has requested that Collateral Agent and Lenders (i) modify the amortization schedule and (ii) make certain other revisions to the Loan Agreement as more fully set forth herein.

D. Collateral Agent and Lenders have agreed to modify and to amend certain provisions of the Loan Agreement, but only to the extent, in accordance with the terms, subject to the conditions and in reliance upon the representations and warranties set forth below.

Agreement

Now Therefore, in consideration of the foregoing recitals and other good and valuable consideration, the receipt and adequacy of which is hereby acknowledged, and intending to be legally bound, the parties hereto agree as follows:

1.Definitions. Capitalized terms used but not defined in this Amendment shall have the meanings given to them in the Loan Agreement.

2.Amendments to Loan Agreement.

2.1Section 10 (Notices). Effective as of December 14, 2020, Collateral Agent’s Notice information in Section 10 of the Loan Agreement hereby is amended and restated as follows:

“OXFORD FINANCE LLC

115 South Union Street, Suite 300

Alexandria, VA 22314

Attention: Legal Department

[Signature Page to First Amendment to Loan and Security Agreement]

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Fax: (703) 519-5225

Email: LegalDepartment@oxfordfinance.com”

2.2Section 13.1 (Definitions). The following term and its definition in Section 13.1 of the Loan Agreement hereby is amended and restated as follows:

“Amortization Date” is, July 1, 2021; provided, however, if a Borrower achieves the Term B Milestone on or prior to June 30, 2021, then the Amortization Date with respect to all Term Loans shall automatically be extended to January 1, 2022.

3.Limitation of Amendment.

3.1The amendments set forth in Section 2, are effective for the purposes set forth herein and shall be limited precisely as written and shall not be deemed to (a) be a consent to any amendment, waiver or modification of any other term or condition of any Loan Document, or (b) otherwise prejudice any right or remedy which Collateral Agent or any Lender may now have or may have in the future under or in connection with any Loan Document.

3.2This Amendment shall be construed in connection with and as part of the Loan Documents and all terms, conditions, representations, warranties, covenants and agreements set forth in the Loan Documents, except as herein amended, are hereby ratified and confirmed and shall remain in full force and effect.

4.Representations and Warranties. To induce Collateral Agent and Lenders to enter into this Amendment, Borrower hereby represents and warrants to Collateral Agent and Lenders as follows:

4.1Immediately after giving effect to this Amendment (a) the representations and warranties contained in the Loan Documents are true, accurate and complete in all material respects as of the date hereof (except to the extent such representations and warranties relate to an earlier date, in which case they are true and correct as of such date), and (b) no Event of Default has occurred and is continuing;

4.2Borrower has the power and authority to execute and deliver this Amendment and to perform its obligations under the Loan Agreement, as amended by this Amendment;

4.3The organizational documents of Borrower delivered to Collateral Agent and Lenders on the Effective Date, or subsequent thereto, remain true, accurate and complete and have not been amended, supplemented or restated and are and continue to be in full force and effect;

4.4The execution and delivery by Borrower of this Amendment and the performance by Borrower of its obligations under the Loan Agreement, as amended by this Amendment, have been duly authorized;

4.5The execution and delivery by Borrower of this Amendment and the performance by Borrower of its obligations under the Loan Agreement, as amended by this Amendment, do not and will not contravene (a) any law or regulation binding on or affecting Borrower, (b) any contractual restriction with a Person binding on Borrower, (c) any order, judgment or decree of any court or other governmental or public body or authority, or subdivision thereof, binding on Borrower, or (d) the organizational documents of Borrower;

4.6The execution and delivery by Borrower of this Amendment and the performance by Borrower of its obligations under the Loan Agreement, as amended by this Amendment, do not require any

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order, consent, approval, license, authorization or validation of, or filing, recording or registration with, or exemption by any governmental or public body or authority, or subdivision thereof, binding on Borrower;

4.7This Amendment has been duly executed and delivered by Borrower and is the binding obligation of Borrower, enforceable against Borrower in accordance with its terms, except as such enforceability may be limited by bankruptcy, insolvency, reorganization, liquidation, moratorium or other similar laws of general application and equitable principles relating to or affecting creditors’ rights; and

4.8That certain Intellectual Property License Agreement by and between Borrower and Equillium Australia and effective as of January 30, 2019 does not violate the restrictions placed on Equillium Australia under Section 7.12 of the Loan Agreement.

5.Release by Borrower.

5.1FOR GOOD AND VALUABLE CONSIDERATION, Borrower hereby forever relieves, releases, and discharges Collateral Agent and each Lender and their respective present or former employees, officers, directors, agents, representatives, attorneys, and each of them, from any and all claims, debts, liabilities, demands, obligations, promises, acts, agreements, costs and expenses, actions and causes of action, of every type, kind, nature, description or character whatsoever, whether known or unknown, suspected or unsuspected, absolute or contingent, arising out of or in any manner whatsoever connected with or related to facts, circumstances, issues, controversies or claims existing or arising from the beginning of time through and including the date of execution of this Amendment solely to the extent such claims arise out of or are in any manner whatsoever connected with or related to the Loan Documents, the Recitals hereto, any instruments, agreements or documents executed in connection with any of the foregoing or the origination, negotiation, administration, servicing and/or enforcement of any of the foregoing (collectively “Released Claims”).

5.2By entering into this release, Borrower recognizes that no facts or representations are ever absolutely certain and it may hereafter discover facts in addition to or different from those which it presently knows or believes to be true, but that it is the intention of Borrower hereby to fully, finally and forever settle and release all matters, disputes and differences, known or unknown, suspected or unsuspected in respect of the Released Claims; accordingly, if Borrower should subsequently discover that any fact that it relied upon in entering into this release was untrue, or that any understanding of the facts was incorrect, Borrower shall not be entitled to set aside this release by reason thereof, regardless of any claim of mistake of fact or law or any other circumstances whatsoever. Borrower acknowledges that it is not relying upon and has not relied upon any representation or statement made by Bank with respect to the facts underlying this release or with regard to any of such party’s rights or asserted rights.

5.3This release may be pleaded as a full and complete defense and/or as a cross-complaint or counterclaim against any action, suit, or other proceeding that may be instituted, prosecuted or attempted in breach of this release. Borrower acknowledges that the release contained herein constitutes a material inducement to Collateral Agent and the Lenders to enter into this Amendment, and that Collateral Agent and the Lenders would not have done so but for Collateral Agent’s and the Lenders’ expectation that such release is valid and enforceable in all events.

5.4Borrower hereby represents and warrants to Collateral Agent and the Lenders, and Collateral Agent and the Lenders are relying thereon, as follows:

(a)Except as expressly stated in this Amendment, neither Collateral Agent, the Lenders nor any agent, employee or representative of any of them has made any statement or representation to Borrower regarding any fact relied upon by Borrower in entering into this Amendment.

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(b)Borrower has made such investigation of the facts pertaining to this Amendment and all of the matters appertaining thereto, as it deems necessary.

(c)The terms of this Amendment are contractual and not a mere recital.

(d)This Amendment has been carefully read by Borrower, the contents hereof are known and understood by Borrower, and this Amendment is signed freely, and without duress, by Borrower.

(e)Borrower is the sole and lawful owner of all right, title and interest in and to every claim and every other matter which it releases herein, and that it has not heretofore assigned or transferred, or purported to assign or transfer, to any person, firm or entity any claims or other matters herein released. Borrower shall indemnify Collateral Agent and the Lenders, defend and hold each harmless from and against all claims based upon or arising in connection with prior assignments or purported assignments or transfers of any claims or matters released herein.

6.Counterparts. This Amendment may be executed in any number of counterparts and all of such counterparts taken together shall be deemed to constitute one and the same instrument.

7.Effectiveness. This Amendment shall be deemed effective upon the due execution and delivery to Collateral Agent and Lenders of (i) this Amendment by each party hereto, and (ii) Borrower’s payment of all Lenders’ Expenses incurred through the date of this Amendment.

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IN WITNESS WHEREOF, the parties hereto have caused this Amendment to the Loan Agreement to be executed as of the date first set forth above.

BORROWER:

EQUILLIUM, INC.

By: /s/ Jason Keyes

Name: Jason Keyes

Title: Chief Financial Officer

COLLATERAL AGENT AND LENDER:

OXFORD FINANCE LLC.

By: /s/ Colette H. Featherly

Name: Colette H. Featherly

Title: Senior Vice President

LENDER:

SILICON VALLEY BANK

By: /s/ Kevin Fleishman

Name: Kevin Fleischman

Title: Director

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