Separation and Release Agreement, dated April 17, 2019, by and between the Company and William D. Schwieterman, M.D

Exhibit 10.1

SEPARATION AGREEMENT AND RELEASE

THIS SEPARATION AGREEMENT AND RELEASE (“Agreement”) is made and entered into by and between Dr. William D. Schwieterman (“Employee”) and Mateon Therapeutics, Inc. (“Company”), and inures to the benefit of each of Company’s current, former and future, as applicable, subsidiaries, affiliates, related entities, successors, officers, directors, shareholders, agents, employees and assigns. The term “Parties” as used in this Agreement means Company and Employee collectively.

RECITALS

A. Employee is an at-will employee of Company, working pursuant to an employment agreement dated May 12, 2015, a July 31, 2015 amendment thereto and an October 2, 2017 amendment thereto;

B. On or about April 17, 2019, the Company intends to enter into an Agreement and Plan of Merger (the “Merger Agreement”) with Oncotelic, Inc. and Oncotelic Acquisition Corporation, a Delaware corporation and wholly-owned subsidiary of the Company (the “Merger Sub”). Upon the terms of and subject to the satisfaction of the conditions described in the Merger Agreement, the Merger Sub will be merged with and into Oncotelic (the “Merger”), with Oncotelic surviving the Merger as a wholly-owned subsidiary of the Company;

C. Employee will separate from Company effective at the closing of the Merger (the “Separation Date”); and

D. The Parties want to resolve any and all actual or potential disputes arising out of or relating to Employee’s employment with Company or the cessation of that employment.

Company and Employee hereby agree as follows:

1. Severance Benefit. In consideration of the covenants and releases in this Agreement, and in lieu of any other severance payments otherwise due and payable to Employee, Company will pay to Employee: (a) a payment of $205,000 in cash, upon the closing of a financing in which at least $10 million in gross proceeds is received by the Company subsequent to the closing of the Merger (a “Post-Closing Financing”), and (b) an additional payment of $205,000 in cash, upon the closing of a Post-Closing Financing in which at least an additional $10 million in gross proceeds is received by the Company. In addition, Company will reimburse Employee for twelve months, starting the month immediately after the Separation Date, for Employee’s monthly COBRA premiums, subject to applicable laws and requirements and Employee’s eligibility and compliance with COBRA and insurance requirements. If Employee obtains other health insurance coverage from another employee, company, or business entity within the twelve months after the Separation Date, Company will no longer be required to pay for or reimburse Employee for COBRA premiums. Employee will inform Company promptly after Employee learns he will be covered by other health insurance and when that coverage begins. The payments described in this paragraph are referred to as the “Severance Benefit”. Employee must comply with all of the terms of this Agreement, and his Confidentiality and Inventions Agreement with the Company (the “Confidentiality Agreement”), in order to receive, or continue to receive, the Severance Benefit.

2. Wages and Vacation Time Paid. Employee acknowledges that Company will pay Employee on the Separation Date all of Employee’s wages due and owing and paid for all accrued-but-unused paid time off. Additionally, Employee acknowledges that Company will reimburse him for all Company business expenses he has incurred up through the Separation Date. Employee’s receipt of these wages, accrued benefits, and reimbursements is not conditioned upon the execution of this Agreement.

Page 1 of 5

3. Release and Waiver by Employee. Employee, on behalf of himself and his heirs, executors, administrators, assigns and successors, fully and forever releases and discharges Company, and, as applicable, its current, former and future subsidiaries and related entities, successors, officers, directors, shareholders, agents, employees and assigns (collectively “Releasees”), from any and all claims, liabilities and causes of action, of every nature, kind and description, in law, equity or otherwise, which have arisen, occurred or existed at any time prior to his signing of this Agreement, including, without limitation, any and all claims, liabilities and causes of action arising out of or relating to Employee’s employment with Company or the cessation of that employment.

4. Waiver of Employment-Related Claims. Employee waives and releases, except the potential claims identified below, all rights, remedies, or claims he may have had or now has against Company or any of the Releasees regarding employment-related causes of action, that are applicable to Employee and Company and to which Company is subject, including without limitation, claims of wrongful discharge, breach of contract, retaliation, breach of the covenant of good faith and fair dealing, fraud, violation of public policy, claims that he is or was a “whistleblower,” defamation, discrimination, personal injury, physical injury, emotional distress, claims under Title VII of the Civil Rights Act of 1964, the Americans With Disabilities Act, Age Discrimination in Employment Act of 1967, the Older Workers Benefit Protection Act of 1990, the Federal Rehabilitation Act, the California Fair Employment and Housing Act, the California Family Rights Act, the Equal Pay Act of 1963, the provisions of the California Labor Code and any other federal, state or local laws and regulations relating to employment, conditions of employment (including wage and hour laws) and/or employment discrimination. Claims not covered by the Employee’s waiver and release are: (a) claims for unemployment insurance benefits, (b) claims under California’s Workers Compensation laws, (c) claims relating to the Company’s express obligations under this Agreement, (d) claims that cannot be waived or released as a matter of law (including, without limitation, administrative claims before the United States Equal Employment Opportunity Commission (“EEOC”), including Employee testifying, assisting or participating in an investigation or proceeding by the EEOC or any comparable state or local agency), and (e) claims under that certain Indemnification Agreement with the Company dated as of July 27, 2015. Employee’s waiver and release, however, are intended to be a complete bar to any recovery or personal benefit by or to Employee regarding any claim (except those which cannot be released under law), including those raised through a charge with the EEOC. Accordingly, nothing in this section will be deemed to limit Company’s right to seek immediate dismissal of the charge or complaint on the basis that Employee’s signing of this Agreement constitutes a full release of any individual rights under the federal discrimination laws, or to seek restitution to the extent permitted by law of the economic benefits provided to Employee under this Agreement in the event Employee successfully challenges the validity of this release and prevails in any claim under the federal discrimination laws.

5. Waiver of Unknown Claims. In executing this Agreement, Employee waives and relinquishes all rights and benefits granted to Employee under the provisions of Section 1542 of the California Civil Code or any similar statute or doctrine. Civil Code Section 1542 provides as follows:

A general release does not extend to claims which the creditor 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.

Employee acknowledges that he has read all of this Agreement, including the above Civil Code section, and that both the general release and Employee’s release of all rights and benefits pursuant to Civil Code Section 1542 are fully understood. In waiving the provisions of Section 1542 of the California Civil Code, Employee acknowledges that he may later discover facts in addition to or different from those which he now believes to be true with respect to the matters released in this Agreement. But, he agrees that he has taken that possibility into account in reaching this Agreement, and that the releases in this Agreement will remain in effect as full and complete releases notwithstanding the discovery or existence of additional or different facts.

Page 2 of 5

6. Severability. If a Court rules that any provision in this Agreement is unenforceable, it will not affect the enforceability of the remaining provisions. The Court may enforce all remaining provisions to the extent permitted by law.

7. Confidential Information. Employee acknowledges that, as a condition to his employment with Company, he executed the Confidentiality Agreement. This Agreement in no way affects, alters, or waives Employee’s obligations or Company’s rights under the Confidentiality Agreement (together with its attached exhibits). Employee’s ongoing compliance with the Confidentiality Agreement is a material condition to this Agreement, and an express condition to Employee’s receipt of the Severance Benefit described in this Agreement.

8. Integrated Agreement. This Agreement (together with the agreements and documents to which it specifically refers) contains the entire agreement of the Parties concerning its subject matter. The Parties did not make any promises or representations to each other that do not appear in this Agreement. This Agreement supersedes all other agreements between the Parties excluding the Confidentiality Agreement.

9. Waiver, Amendment and Modification. No waiver, amendment or modification of this Agreement’s terms is effective unless it is in writing and signed by all parties affected by the waiver, amendment or modification. The Parties’ waiver of any term or condition of this Agreement will not be construed as a waiver of any other term or condition.

10. Counterparts. This Agreement may be signed in counterparts and those counterparts will be treated as if they were one signed document.

11. Employee’s Right To Release. Employee warrants and represents that (a) Employee has not assigned or transferred, or purported to assign or transfer, and that Employee will not in the future assign or transfer to any person or entity, any right or claim released by this Agreement, any part thereof, or any interest therein, and (b) Employee is the sole owner of the rights and claims released in this Agreement.

12. Venue and Governing Law. The validity, interpretation, enforceability, and performance of this Agreement must be governed by and construed in accordance with the laws of the State of California, exclusive of its choice-of-law rules. Any action arising under or relating to this Agreement must be commenced and maintained in the federal or state courts as applicable in San Francisco County, California. The parties agree to the personal jurisdiction of these Courts in San Francisco County.

13. Tax Liability. Employee assumes full responsibility for any and all taxes, interest and/or penalties that may be assessed upon the Severance Benefit.

14. Consideration/Revocation Period. This Agreement is intended to release and discharge any claims by Employee under the Age Discrimination in Employment Act. To satisfy the requirements of the Older Workers’ Benefit Protection Act, 29 U.S.C. section 626(f), as applicable:

Page 3 of 5

[Signature Page Follows]

Page 4 of 5

IN WITNESS WHEREOF, the Parties have executed this Agreement as of the dates written below.

Page 5 of 5