Separation Agreement and Release entered into by and between the Registrant and Elaine Sun, dated December 17, 2019

Exhibit 10.10

SEPARATION AGREEMENT AND RELEASE

This Separation Agreement and Release (“Agreement”) is made by and between ELAINE SUN (“Employee”) and SutroVax, Inc. (the “Company”) (collectively referred to as the “Parties” or individually referred to as a “Party”).

RECITALS

WHEREAS, Employee was employed by the Company;

WHEREAS, Employee signed an At-Will Employment, Confidential Information, Invention Assignment, and Arbitration Agreement with the Company on 13 December 2016 (the “Confidentiality Agreement”);

WHEREAS, the Company and Employee have entered into Stock Option Agreements, dated 13 January 2017, 18 May 2017, 24 July 2018, and 21 March 2019, granting Employee the option to purchase shares of the Company’s common stock subject to the terms and conditions of the Company’s 2014 Stock Option Plan and the Stock Option Agreement (collectively the “Stock Agreements”);

WHEREAS, Employee separated from employment with the Company effective 31 December 2019 (the “Separation Date”); and

WHEREAS, the Parties wish to resolve any and all disputes, claims, complaints, grievances, charges, actions, petitions, and demands that the Employee may have against the Company and any of the Releasees as defined below, including, but not limited to, any and all claims arising out of or in any way related to Employee’s employment with or separation from the Company.

NOW, THEREFORE, in consideration of the mutual promises made herein, the Company and Employee hereby agree as follows:

COVENANTS

1. Consideration.

a. Payment. Incorporating by reference and pursuant to sections 9(a) and 9(b) of the Sun Employment Agreement (effective date 1 January 2017), the Company agrees to pay Employee an aggregate of nine (9) months of Employee’s base salary, for a total of Two Hundred Sixty Thousand Two Hundred Fifty Dollars ($260,250.00), less applicable withholdings. Payments will be made periodically in equal installments in accordance with the Company’s normal payroll practices.

b. Bonus. The Company shall also pay Employee an Annual Bonus (as defined in the Employment Agreement) based on the Board approved attainment of corporate objectives in-line with other senior level executives.

c. COBRA. Incorporating by reference and pursuant to sections 9(a) and 9(b) of the Sun Employment Agreement (effective date 1 January 2017), the Company shall reimburse Employee for the payments Employee makes for COBRA coverage for a period of twelve (12) months, or until Employee has secured health insurance coverage through another employer, whichever occurs first, provided Employee timely elects and pays for continuation coverage pursuant to the Consolidated Omnibus Budget Reconciliation Act of 1985, as amended (“COBRA”), within the time period prescribed pursuant to COBRA. COBRA reimbursements shall be made by the Company to Employee consistent with the Company’s normal expense reimbursement policy, provided that Employee submits documentation to the Company substantiating Employee’s payments for COBRA coverage.

d. Acknowledgement. Incorporating by reference and pursuant to sections 9(a) and 9(b) of the Sun Employment Agreement (effective date 1 January 2017), the Employee acknowledges that without this Agreement, Employee is otherwise not entitled to the consideration listed in this Paragraph 1.

2. Stock. The Parties agree that for purposes of determining the number of shares of the Company’s common stock that Employee is entitled to purchase from the Company, pursuant to the exercise of outstanding options, Employee will be considered to have vested only up to the Separation Date.

Employee acknowledges that as of the Separation Date, Employee will have vested in the options as summarized in Schedule A, attached hereto. The Company, on condition of execution and effectuation of this Agreement, will consider a remaining 118,562 shares made up of (i) the security ES-061 unvested options granted on 18 May 2017 totaling 36,288, (ii) the security ES-095 unvested options granted on 24 July 2018 totaling 64,584 and (iii) the security ES-139 unvested options granted on 21 March 2019 totaling 17,690 to be vested. The exercise of Employee’s vested options and shares shall continue to be governed by the terms and conditions of the Company’s Stock Agreements.

3. Benefits. Employee’s health insurance benefits shall cease on 31 December 2019, subject to Employee’s right to continue Employee’s health insurance under COBRA. Employee’s participation in all benefits and incidents of employment, including, but not limited to, vesting in stock options, and the accrual of bonuses, vacation, and paid time off, ceased as of the Separation Date.

4. Payment of Salary and Receipt of All Benefits. Employee acknowledges and represents that, other than the consideration set forth in this Agreement, the Company has paid or provided all salary, wages, bonuses, accrued vacation/paid time off, premiums, leaves, housing allowances, relocation costs, interest, severance, outplacement costs, fees, reimbursable expenses, commissions, stock, stock options, vesting, and any and all other benefits and compensation due to Employee.

5. Release of Claims. Employee agrees that the foregoing consideration represents settlement in full of all outstanding obligations owed to Employee by the Company and its current and former officers, directors, employees, agents, investors, attorneys, shareholders, administrators, affiliates, benefit plans, plan administrators, professional employer organization or co-employer, insurers,

trustees, divisions, and subsidiaries, and predecessor and successor corporations and assigns, (collectively, the “‘Releasees”). Employee, on Employee’s own behalf and on behalf of Employee’s respective heirs, family members, executors, agents, and assigns, hereby and forever releases the Releasees from, and agrees not to sue concerning, or in any manner to institute, prosecute, or pursue, any claim, complaint, charge, duty, obligation, demand, or cause of action relating to any matters of any kind, whether presently known or unknown, suspected or unsuspected, that Employee may possess against any of the Releasees arising from any omissions, acts, facts, or damages that have occurred up until and including the Effective Date of this Agreement, including, without limitation:

a. any and all claims relating to or arising from Employee’s employment relationship with the Company and the termination of that relationship;

b. any and all claims relating to, or arising from, Employee’s right to purchase, or actual purchase of shares of stock of the Company, including, without limitation, any claims for fraud, misrepresentation, breach of fiduciary duty, breach of duty under applicable state corporate law, and securities fraud under any state or federal law;

c. any and all claims for wrongful discharge of employment, termination in violation of public policy, discrimination, harassment, retaliation. breach of contract (both express and implied), breach of covenant of good faith and fair dealing (both express and implied), promissory estoppel, negligent or intentional infliction of emotional distress, fraud, negligent or intentional misrepresentation, negligent or intentional interference with contract or prospective economic advantage, unfair business practices, defamation, libel, slander, negligence, personal injury, assault, battery, invasion of privacy, false imprisonment, conversion, and disability benefits;

d. any and all claims for violation of any federal, state, or municipal statute, including, but not limited to, Title VII of the Civil Rights Act of 1964, the Civil Rights Act of 1991, the Rehabilitation Act of 1973, the Americans with Disabilities Act of 1990, the Equal Pay Act, the Fair Labor Standards Act, the Fair Credit Reporting Act, the Age Discrimination in Employment Act of 1967, the Older Workers Benefit Protection Act, the Employee Retirement Income Security Act of 1974, the Worker Adjustment and Retraining Notification Act, the Family and Medical Leave Act, the Sarbanes-Oxley Act of 2002, the Immigration Reform and Control Act, the California Family Rights Act, the California Labor Code, the California Workers’ Compensation Act, and the California Fair Employment and Housing Act;

e. any and all claims for violation of the federal or any state constitution;

f. any and all claims arising out of any other laws and regulations relating to employment or employment discrimination;

g. any claim for any loss, cost, damage, or expense arising out of any dispute over the nonwithholding or other tax treatment of any of the proceeds received by Employee as a result of this Agreement; and

h. any and all claims for attorneys’ fees and costs.

Employee agrees that the release set forth in this section shall be and remain in effect in all respects as a complete general release as to the matters released. This release does not extend to any obligations incurred under this Agreement or rights to benefits under any retirement plan in which the Employee is a participant according to the terms of the plan. This release does not release claims that cannot be released as a matter of law, including any Protected Activity (as defined below). Any and all disputed wage claims that are released herein shall be subject to binding arbitration in accordance with the Arbitration Paragraph below, except as required by applicable law. This release does not extend to any right Employee may have to (i) unemployment compensation benefits; (ii) workers’ compensation benefits; or (iii) any right the Employee may have to COBRA benefits and any vested retirement benefits and/or 401(k) plan benefits for which she is eligible in accordance with the terms of the respective employee benefit plans.

6. Acknowledgment of Waiver of Claims under ADEA. Employee acknowledges that Employee is waiving and releasing any rights Employee may have under the Age Discrimination in Employment Act of 1967 (“ADEA”), and that this waiver and release is knowing and voluntary. Employee agrees that this waiver and release does not apply to any rights or claims that may arise under the ADEA after the Effective Date of this Agreement. Employee acknowledges that the consideration given for this waiver and release is in addition to anything of value to which Employee was already entitled. Employee further acknowledges that he/she has been advised by this writing that: (a) Employee should consult with an attorney prior to executing this Agreement; (b) Employee has twenty-one (21) days within which to consider this Agreement; (c) Employee has seven (7) days following Employee’s execution of this Agreement to revoke this Agreement; (d) this Agreement shall not be effective until after the revocation period has expired; and (e) nothing in this Agreement prevents or precludes Employee from challenging or seeking a determination in good faith of the validity of this waiver under the ADEA, nor does it impose any condition precedent, penalties, or costs for doing so, unless specifically authorized by federal law. In the event Employee signs this Agreement and returns it to the Company in less than the 21-day period identified above, Employee hereby acknowledges that Employee has freely and voluntarily chosen to waive the time period allotted for considering this Agreement. Employee acknowledges and understands that revocation must be accomplished by a written notification to the person executing this Agreement on the Company’s behalf that is received prior to the Effective Date. The Parties agree that changes, whether material or immaterial, do not restart the running of the 21-day period.

7. California Civil Code Section 1542. Employee acknowledges that Employee has been advised to consult with legal counsel and is familiar with the provisions of California Civil Code Section 1542, a statute that otherwise prohibits the release of unknown claims, which provides as follows:

A GENERAL RELEASE DOES NOT EXTEND TO CLAIMS WHICH THE CREDITOR OR RELEASING PARTY DOES NOT KNOW OR SUSPECT TO EXIST IN HIS OR HER FAVOR AT THE TIME OF EXECUTING THE RELEASE, WHICH IF KNOWN BY HIM OR HER MUST HAVE MATERIALLY AFFECTED HIS OR HER SETTLEMENT WITH THE DEBTOR OR RELEASED PARTY.

Employee, being aware of said code section, agrees to expressly waive any rights Employee may have thereunder, as well as under any other statute or common law principles of similar effect.

8. No Pending or Future Lawsuits. Employee represents that Employee has no lawsuits, claims, or actions pending in Employee’s name, or on behalf of any other person or entity, against the Company or any of the other Releasees. Employee also represents that Employee does not intend to bring any claims on Employee’s own behalf or on behalf of any other person or entity against the Company or any of the other Releasees.

9. Application for Employment. Employee understands and agrees that, as a condition of this Agreement, Employee shall not be entitled to any employment with the Company, and Employee hereby waives any right, or alleged right, of employment or re-employment with the Company.

10. Confidentiality. Subject to the Protected Activity Paragraph below, Employee agrees to maintain in complete confidence the existence of this Agreement, the contents and terms of this Agreement, and the consideration for this Agreement (hereinafter collectively referred to as “Separation Information”). Except as required by law, Employee may disclose Separation Information only to Employee’s immediate family members, the Court in any proceedings to enforce the terms of this Agreement, Employee’s attorney(s), and Employee’s accountant(s) and any professional tax advisor(s) to the extent that they need to know the Separation Information in order to provide advice on tax treatment or to prepare tax returns, and must prevent disclosure of any Separation Information to all other third parties. Employee agrees that Employee will not publicize, directly or indirectly, any Separation Information.

11. Trade Secrets and Confidential Information/Company Property. Employee reaffirms and agrees to observe and abide by the terms of the Confidentiality Agreement, specifically including the provisions therein regarding nondisclosure of the Company’s trade secrets and confidential and proprietary information. Employee’s signature below constitutes Employee’s certification under penalty of perjury that Employee has returned all documents and other items provided to Employee by the Company (with the exception of a copy of the Employee Handbook and personnel documents specifically relating to Employee), developed or obtained by Employee in connection with Employee’s employment with the Company, or otherwise belonging to the Company. Notwithstanding anything herein to the contrary, under the federal Defend Trade Secrets Act of 2016, an individual may not be held criminally or civilly liable under any Federal or State trade secret law for the disclosure of a trade secret that (A) is made (i) in confidence to a Federal, State, or local government official, either directly or indirectly, or to an attorney; and (ii) solely for the purpose of reporting or investigating a suspected violation of law; or (B) is made in a complaint or other document filed in a lawsuit or other proceeding, if such filing is made under seal. An individual who files a lawsuit for retaliation by an employer for reporting a suspected violation of law may disclose the trade secret to the attorney of the individual and use the trade secret information in the court proceeding if the individual files any document containing the trade secret under seal and does not disclose the trade secret except pursuant to court order. Nothing herein is intended, or should be construed, to affect the immunities created by the Defend Trade Secrets Act of 2016.

12. No Cooperation. Subject to the Protected Activity paragraph below, Employee agrees that Employee will not knowingly encourage, counsel, or assist any attorneys or their clients in the presentation or prosecution of any disputes, differences, grievances, claims, charges, or complaints by any third party against any of the Releasees, unless under a subpoena or other court order to do so or as related directly to the ADEA waiver in this Agreement. Employee agrees both to immediately notify the Company upon receipt of any such subpoena or court order, and to furnish, within three (3) business days of its receipt, a copy of such subpoena or other court order. If approached by anyone for counsel or assistance in the presentation or prosecution of any disputes, differences, grievances, claims, charges, or complaints against any of the Releasees, Employee shall state no more than that Employee cannot provide counsel or assistance.

13. Protected Activity Not Prohibited. Employee understands that nothing in this Agreement shall in any way limit or prohibit Employee from engaging in any Protected Activity. For purposes of this Agreement, “Protected Activity” shall mean filing a charge, complaint, or report with, or otherwise communicating, cooperating, or participating in any investigation or proceeding that may be conducted by, any federal, state or local government agency or commission, including but not limited to the Securities and Exchange Commission, the Equal Employment Opportunity Commission, the Occupational Safety and Health Administration, and the National Labor Relations Board (“Government Agencies”). Employee understands that in connection with such Protected Activity, Employee is permitted to disclose documents or other information as permitted by law, and without giving notice to, or receiving authorization from, the Company. However, Employee waives the right to recover any personal damages or other personal relief based on any claim, cause of action, demand, lawsuit or similar that is waived pursuant to this Agreement and brought by Employee or on Employee’s behalf by any third party, including as a member of any class or collective action, except that Employee does not waive any right to receive and fully retain any monetary award from a government-administered whistleblower award program for providing information to a government agency. Notwithstanding the foregoing, Employee agrees to take all reasonable precautions to prevent any unauthorized use or disclosure of any information that may constitute Company confidential information under the Confidentiality Agreement to any parties other than the Government Agencies. Employee further understands that “Protected Activity” does not include the disclosure of any Company attorney-client privileged communications; Any language in the Confidentiality Agreement regarding Employee’s right to engage in Protected Activity that conflicts with, or is contrary to, this paragraph is superseded by this Agreement.

14. Nondisparagement. Employee agrees to refrain from any disparagement, defamation, libel, or slander of any of the Releasees, and agrees to refrain from any tortious interference with the contracts and relationships of any of the Releasees. The Releasees agree to refrain from any disparagement, defamation, libel, or slander of Employee. Employee shall direct any inquiries by potential future employers to the Company’s human resources department, which shall use its best efforts to provide only the Employee’s last position and dates of employment.

15. Breach. In addition to the rights provided in the “Attorneys’ Fees” section below, Employee acknowledges and agrees that any material breach of this Agreement, unless such breach constitutes a legal action by Employee challenging or seeking a determination in good faith of the validity of the waiver herein under the ADEA, or of any provision of the Confidentiality Agreement shall entitle the Company immediately to recover and/or cease providing the consideration provided to Employee under this Agreement and to obtain damages, except as provided by law.

16. No Admission of Liability. Employee understands and acknowledges that this Agreement constitutes a compromise and settlement of any and all actual or potential disputed claims by Employee. No action taken by the Company hereto, either previously or in connection with this Agreement, shall be deemed or construed to be (a) an admission of the truth or falsity of any actual or potential claims or (b) an acknowledgment or admission by the Company of any fault or liability whatsoever to Employee or to any third party.

17. Costs. The Parties shall each bear their own costs, attorneys’ fees, and other fees incurred in connection with the preparation of this Agreement.

18. ARBITRATION.

ARBITRATION. THE PARTIES AGREE THAT ANY AND ALL DISPUTES ARISING OUT OF THE TERMS OF THIS AGREEMENT, THEIR INTERPRETATION, EMPLOYEE’S EMPLOYMENT WITH THE CORPS OR THE TERMS THEREOF, OR ANY OF THE MATTERS HEREIN RELEASED, SHALL BE SUBJECT TO ARBITRATION IN SAN MATEO COUNTY, BEFORE A NEUTRAL ARBITRATOR WITH JUDICIAL ARBITRATION & MEDIATION SERVICES (“JAMS”), PURSUANT TO ITS EMPLOYMENT ARBITRATION RULES & PROCEDURES (“JAMS RULES”). THE ARBITRATOR MAY GRANT INJUNCTIONS AND ALL OTHER RELIEF AVAILABLE AT LAW AND EQUITY IN SUCH DISPUTES. THE ARBITRATOR SHALL ADMINISTER AND CONDUCT ANY ARBITRATION IN ACCORDANCE WITH CALIFORNIA LAW, INCLUDING THE CALIFORNIA CODE OF CIVIL PROCEDURE, AND THE ARBITRATOR SHALL APPLY SUBSTANTIVE AND PROCEDURAL CALIFORNIA LAW TO ANY DISPUTE OR CLAIM. WITHOUT REFERENCE TO ANY CONFLICT-OF-LAW PROVISIONS OF ANY JURISDICTION. TO THE EXTENT THAT THE JAMS RULES CONFLICT WITH CALIFORNIA LAW, CALIFORNIA LAW SHALL TAKE PRECEDENCE. THE DECISION OF THE ARBITRATOR SHALL BE FINAL, CONCLUSIVE, AND BINDING ON THE PARTIES TO THE ARBITRATION. THE ARBITRATOR SHALL IN ALL CASES ISSUE A WRITTEN AWARD AND THE PARTIES AGREE THAT THE PREVAILING PARTY IN ANY ARBITRATION SHALL BE ENTITLED TO INJUNCTIVE RELIEF IN ANY COURT OF COMPETENT JURISDICTION TO ENFORCE THE ARBITRATION AWARD. THE EMPLOYEE SHALL PAY THE EQUIVALENT AMOUNT OF THE FILING FEES ASSOCIATED WITH A CIVIL COURT ACTION; THE EMPLOYER SHALL PAY ALL OTHER COSTS AND EXPENSES OF SUCH ARBITRATION. EACH PARTY SHALL SEPARATELY PAY FOR ITS OWN RESPECTIVE COUNSEL FEES AND EXPENSES ASSOCIATED WITH ARBITRATION; PROVIDED, HOWEVER, THAT THE ARBITRATOR SHALL AWARD ATTORNEYS’ FEES AND COSTS TO THE PREVAILING PARTY, EXCEPT AS PROHIBITED BY LAW. THE PARTIES HEREBY AGREE TO WAIVE THEIR RIGHT TO HAVE ANY DISPUTE BETWEEN THEM RESOLVED IN A COURT OF LAW BY A JUDGE OR JURY. NOTWITHSTANDING THE FOREGOING, THIS SECTION WILL NOT PREVENT EITHER PARTY FROM SEEKING INJUNCTIVE RELIEF (OR ANY OTHER PROVISIONAL REMEDY) FROM ANY COURT HAVING JURISDICTION OVER THE PARTIES AND THE SUBJECT MATTER OF THEIR DISPUTE RELATING TO THIS AGREEMENT AND THE AGREEMENTS INCORPORATED HEREIN BY REFERENCE. SHOULD ANY PART OF THE ARBITRATION AGREEMENT CONTAINED IN THIS PARAGRAPH CONFLICT WITH ANY OTHER ARBITRATION AGREEMENT BETWEEN THE PARTIES, THE PARTIES AGREE THAT THIS ARBITRATION AGREEMENT SHALL GOVERN.

19. Tax Consequences. The Company makes no representations or warranties with respect to the tax consequences of the payments and any other consideration provided to Employee or made on Employee’s behalf under the terms of this Agreement. Employee agrees and understands that Employee is responsible for payment, if any, of local, state, and/or federal taxes on the payments and any other consideration provided hereunder by the Company and any penalties or assessments thereon. Employee further agrees to indemnify and hold the Releasees harmless from any claims, demands, deficiencies, penalties, interest, assessments, executions, judgments, or recoveries by any government agency against the Company for any amounts claimed due on account of (a) Employee’s failure to pay or delayed payment of federal or state taxes, or (b) damages sustained by the Company by reason of any such claims, including attorneys’ fees and costs.

20. Authority. The Company represents and warrants that the undersigned has the authority to act on behalf of the Company and to bind the Company and all who may claim through it to the terms and conditions of this Agreement. Employee represents and warrants that Employee has the capacity to act on Employee’s own behalf and on behalf of all who might claim through Employee to bind them to the terms and conditions of this Agreement. Each Party warrants and represents that there are no liens or claims of lien or assignments in law or equity or otherwise of or against any of the claims or causes of action released herein.

21. Severability. In the event that any provision or any portion of any provision hereof or any surviving agreement made a part hereof becomes or is declared by a court of competent jurisdiction or arbitrator to be illegal, unenforceable, or void, this Agreement shall continue in full force and effect without said provision or portion of provision.

22. Attorneys’ Fees. Except with regard to a legal action challenging or seeking a determination in good faith of the validity of the waiver herein under the ADEA, in the event that either Party brings an action to enforce or effect its rights under this Agreement, the prevailing Party shall be entitled to recover its costs and expenses, including the costs of mediation, arbitration, litigation, court fees, and reasonable attorneys’ fees incurred in connection with such an action.

23. Entire Agreement. This Agreement represents the entire agreement and understanding between the Company and Employee concerning the subject matter of this Agreement and Employee’s employment with and separation from the Company and the events leading thereto and associated therewith, and supersedes and replaces any and all prior agreements and understandings concerning the subject matter of this Agreement and Employee’s relationship with the Company, with the exception of the Confidentiality Agreement, except as otherwise modified or superseded herein.

24. No Oral Modification. This Agreement may only be amended in a writing signed by Employee and the Company’s Chief Executive Officer.

25. Governing Law. This Agreement shall be governed by the laws of the State of California, without regard for choice-of-law provisions. Employee consents to personal and exclusive jurisdiction and venue in the State of California.

26. Effective Date. Employee understands that this Agreement shall be null and void if not executed by Employee within twenty-one (21) days of the Separation Date. Each Party has seven (7) days after that Party signs this Agreement to revoke it. This Agreement will become effective on the eighth (8th) day after Employee signed this Agreement, so long as it has been signed by the Parties and has not been revoked by either Party before that date (the “Effective Date”).

27. Counterparts. This Agreement may be executed in counterparts and each counterpart shall be deemed an original and all of which counterparts taken together shall have the same force and effect as an original and shall constitute an effective, binding agreement on the part of each of the undersigned. The counterparts of this Agreement may be executed and delivered by email PDF or other electronic transmission or signature.

28. Voluntary Execution of Agreement. Employee understands and agrees that Employee executed this Agreement voluntarily, without any duress or undue influence on the part or behalf of the Company or any third party, with the full intent of releasing all of Employee’s claims against the Company and any of the other Releasees. Employee acknowledges that:

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IN WITNESS WHEREOF, the Parties have executed this Agreement on the respective dates set forth below.