Employment Letter Agreement, dated February 7, 2021, by and between Mark Stenhouse and the Registrant

1.

Initial Salary: $425,000 U.S. Dollars on an annualized basis (the “Base Salary”), to be paid bi-weekly in accordance with the Company’s payroll practices. Compensation is subject to periodic reviews and adjustments at the Company’s discretion.

2.

Signing Bonus: You will be eligible to receive a signing bonus of $25,000 payable within 30 days of your start date to cover temporary housing costs in San Diego.

3.

Annual Bonus Plan: You will be eligible to receive an annual performance bonus. Your initial bonus target (your “Target Bonus”) shall be 40% of your Base Salary for the applicable year. Actual bonus payments are based on your continuous performance of services to the Company, the achievement of individual and corporate goals, and the approval of Company management. Bonus payouts may be more or less than the targeted amount based on the before mentioned criteria. Except as described in Section 2 (“At-Will Employment; Severance”) of Additional Information Regarding Employment at Prometheus Following the Employment Start Date below, you must be an active employee of the Company on the date bonuses are distributed to be eligible for a bonus payout. Your annual bonus for 2021 will be pro-rated to reflect the portion of such year following your Employment Start Date.

4.

Employee Benefits: As a regular employee of the Company, you will be eligible to participate in a number of Company-sponsored benefits. In addition, you will be entitled to paid time off in accordance with the Company’s paid time off policy, as in effect from time to time. Terms and conditions of each plan or program are subject to applicable laws, regulations and policies. Should there be a conflict between a plan document and this information, the plan document will always govern. The Company reserves the right to change, alter, or terminate any benefit plan at its sole discretion.

5.

Withholding: All amounts payable to you will be subject to appropriate payroll deductions and all required withholdings.

1.

Consulting Terms: Commencing with your acceptance of this Agreement (the “Consulting Start Date”), you will provide consulting services to the Company on the terms and conditions set forth herein in order to support the Company prior to the Employment Start Date and the date you commence full-time employment. Your consulting services pursuant to this paragraph shall automatically terminate on the first to occur of (a) the Employment Start Date or (b) March 31, 2021. In addition, either party may terminate your consulting services upon sixty (60) days’ written notice to the other party.

2.

Scope of Services During Consulting Period: During the term of your consulting services, you will use reasonable efforts to devote such percentage of your business time and effort to the performance of his services hereunder as shall be mutually agreed upon by you and the Company’s President and Chief Executive Officer, and you shall provide such additional information, advice and assistance

3.

Availability: In connection with your consulting services to the Company, you agree to: (a) be available for consultation by telephone, fax or e-mail on a regular basis on reasonable prior notice during regular business hours; and (b) be available to attend meetings with the Company’s executive team or persons designated by any of the members of the Company’s management team, at the Company’s headquarters or other offices, on reasonable prior notice.

4.

Status as Independent Contractor: Notwithstanding any provision of this Agreement to the contrary, during the period of your consulting services, you acknowledge that you are and shall at all times be an independent contractor, you are not an agent or employee of the Company and you are not authorized to bind the Company or otherwise act on behalf of the Company. Nothing herein contained shall be deemed to create an agency, joint venture, partnership or franchise relationship between the parties hereto. Prior to the Employment Start Date, you shall have no right under this Agreement, or as a result of your services to the Company, to participate in any employee, retirement, insurance or other benefit program of the Company, nor will the Company make any deductions from your compensation for taxes, the payment of which shall be solely your responsibility. You represent and warrant that neither this Agreement nor the performance thereof will conflict with or violate any obligation you may have to, or the right of any, third party.

5.

Other Work Activities: During the term of your consulting services, you may engage in employment, consulting or other work relationships in addition to your work for the Company, provided that such engagements do not violate the provisions of this Agreement. The Company will not be entitled to any setoff or other reduction in its payments hereunder as a result of such permitted other work activities.

6.

Compensation: Your compensation for any consulting services under this Agreement shall include the grant and vesting of the Option (as described below) and such other compensation as shall be mutually agreed between you and the Company in writing.

7.

Stock Options: Subject to the approval of the Company’s Board of Directors or its Compensation Committee, you will be granted an option to purchase 2,400,000 shares of the Company’s Common Stock (the “Option”) as soon as reasonably practicable following your Consulting Start Date. The exercise price per share of the Option will be determined by the Board of Directors or the Compensation Committee when the Option is granted. The Option will be subject to the terms and conditions applicable to options granted under the Company’s 2017 Equity Incentive Plan (the “Plan”), as described in the Plan and the applicable Stock Option Agreement. You will vest in 25% of the Option shares on the one year anniversary of your Consulting Start Date, and the balance will vest in equal monthly installments over the next 36 months of continuous service, as described in the applicable Stock Option Agreement, subject to the accelerated vesting described in Section 2 (“At-Will Employment”; Severance) of Additional Information Regarding Employment at Prometheus below. In the event you do not commence employment with the Company as its Chief Operating Officer on the terms set forth in this Agreement prior to the Employment Start Date Deadline, the Option will terminate immediately, regardless of whether you continue as a consultant to the Company following such date.

1.

Background Check: Please understand that the offer of employment is contingent upon your successful completion of a background check, including a healthcare sanctions check. Additionally, this offer of employment and your continued employment with Prometheus is contingent on your obtaining and keeping the licenses, credentials, permits, certifications and such similar authorizations necessary to perform your job. Prometheus reserves the right, in its sole discretion, to rescind this offer based on the results of the background check.

2.

At-Will Employment; Severance: Your employment with the Company is at-will. This at-will employment relationship cannot be changed except in writing signed by an executive officer of the Company. You may terminate your employment with the Company at any time and for any reason whatsoever simply by notifying the Company. Likewise, the Company may terminate your employment at any time and for any reason whatsoever, with or without Cause (as defined below) or advance written notice.

(i)

an amount equal to your monthly Base Salary as then in effect on the date of your termination (the “Separation Date”) and prior to any reduction in such Base Salary that would permit you to voluntarily terminate employment for Good Reason for the number of months in the Severance Period (as defined below) (the “Severance Payment”), to be paid in substantially equal installments over the Severance Period in accordance with the Company’s regular payroll schedule, with the first such installment commencing on the first regularly scheduled payroll date following the date your Release becomes effective (which first installment will include any installments that would have occurred prior to such date in accordance with the Company’s regular payroll schedule);

(ii)

an amount equal to (A) your Target Bonus for the fiscal year in which the Separation Date occurs, multiplied by (B) (1) 50% if your Qualifying Termination occurs prior to the first anniversary of your Employment Start Date or (2) 100% in the event your Qualifying Termination occurs on or after the first anniversary of your Employment Start Date, to be paid in a single lump sum on the first regularly scheduled payroll date following the date your Release becomes effective, but in no event more than 75 days following the Separation Date (which Target Bonus to be calculated based on your annualized Base Salary rate as then in effect on the Separation Date and prior to any reduction in such Base Salary that would permit you to voluntarily terminate employment for Good Reason);

(iii)

the right to continued health care benefits under the Company’s health insurance plans pursuant to the Consolidated Omnibus Budget reconciliation Act of 1985, as amended (“COBRA”), for you and your eligible dependents who were covered under the Company’s health insurance plans as of the Separation Date paid by the Company for a period commencing on the Separation Date and ending on the earlier of (a) the last day of the Severance Period or (b) the date on which you become eligible for healthcare insurance with a subsequent employer or (c) the date on which the applicable continuation period under COBRA expires (provided that, if any of the Company’s health benefits are self-funded as of the Separation Date, or if the Company cannot provide the foregoing benefits in a manner that is exempt from Section 409A of the Internal Revenue Code of 1986, as amended (the “Code”), or that is otherwise compliant with applicable law (including, without limitation, Section

(iv)

accelerated vesting of all of the Company’s equity awards that are subject to time vesting conditions effective as of the Separation Date.

3.

Authorization to Work: Federal government regulations require that all prospective employees present documentation verifying their identity and demonstrating that they are authorized to work in the United States. Such documentation must be provided to the Company no later than three (3) business days after your date of hire, or the Company’s employment relationship with you may be terminated.

4.

Policies and Procedures: As a Company consultant and employee, you will be expected to abide by Company rules, policies, and regulations as they may be interpreted, adopted, revised or deleted from time to time in the Company’s sole discretion. You will be specifically required to sign an acknowledgement that you have read and understand the Company’s policies and procedures that govern the terms and conditions of your employment, including but not limited to the Employee Handbook and the Code of Ethical Business Conduct.

5.

Confidential Information: To enable the Company to safeguard its proprietary and confidential information, it is a condition of employment that you agree to sign the Company’s standard form of Employee Confidential Information and Inventions Agreement. A copy of this agreement is attached hereto as Exhibit A for your review, and shall be signed by you no later than your Consulting Start Date. We understand that you may have signed similar agreements with prior employers, and wish to impress upon you that you are prohibited from using or disclosing the confidential or proprietary information of others during your employment by the Company. You agree not to bring to the Company or use in the performance of your responsibilities at the Company any materials or documents of a former employer that are not generally available to the public, unless you have obtained express written authorization from the former employer for the possession and use of such materials or documents.

6.

Arbitration: Prometheus has a policy of arbitration for settlement of any dispute between consultants and employees or former consultants or employees and the Company. The Arbitration Agreement, attached hereto Exhibit B, shall be signed by you no later than your Consulting Start Date.

7.

Complete Offer and Agreement: This Agreement, together with the Employee Confidential Information and Inventions Agreement and the Arbitration Agreement, contains the complete understanding and agreement regarding the terms of your employment by the Company. There are no other, different or prior agreements or understandings, written or oral, on this or related subjects. Changes to the terms of your employment can be made only in a writing signed by you and an executive officer of the Company, although it is understood that the Company may, from time to time, in its sole discretion, adjust the salaries, incentive compensation and benefits paid to you and its other employees, as well as job titles, locations, duties, responsibilities, assignments and reporting relationships. This Agreement shall be construed in accordance with the laws of the State of California, without regard to conflicts-of-law principles.

Best Regards,

/s/ Mark McKenna

Mark McKenna

President and CEO

Signature:

/s/ Mark Stenhouse

Name:

Mark Stenhouse

Date:

02/09/2021