Offer Letter between BioAtla, LLC and Christian Vasquez, dated October 22, 2015

Your title will be Corporate Controller. Your duties and responsibilities will include financial controls, financial reporting and planning and such other duties as shall be assigned to you from time to time by the Chief Financial Officer, unless modified in the future by the Chief Executive Officer. Your main work location will be at the Company's corporate headquarters in San Diego, California, although you may be required to travel on behalf of the Company, as and when directed by the Company.

Your employment is to begin effective as of November 9, 2015 (the "Start Date”).

You will receive a base salary at the annualized rate of $145,000 (the "Base Salary"), which shall be subject to standard payroll deductions and withholdings and paid on a regular basis in accordance with the Company's normal payroll procedures and policies. You will also be eligible to accrue paid vacation, and be eligible for the other benefits that the Company provides to comparable employees, in accordance with the Company's policies and procedures.

You will be eligible to earn annual discretionary incentive compensation up to a target amount of twenty percent (20%) of your Base Salary, based on achievement of individual and corporate performance targets, metrics and/or management-by-objectives ("MBOs")to be determined and approved by the Company. Annual incentive compensation is paid on an annual basis, after the close of the fiscal year and after determination by the Company of (i) the level of achievement of the applicable individual and corporate performance targets, metrics and/or MBOs, and (ii) the amount of any annual incentive compensation earned by you. No annual incentive compensation is guaranteed and, in addition to the other conditions for earning such compensation, you must remain an employee in good standing of the Company on the scheduled annual incentive compensation payment date in order to be eligible for any annual incentive compensation. This annual incentive compensation program will be the only incentive compensation, commission, or other bonus program that will apply to you. For the 2015 annual incentive compensation period, your eligibility will be prorated based on the Start Date.

Following the Start Date and subject to Board approval and your signing of the appropriate related agreements, you will be entitled to receive 100,000 Class B Profits Interest Units of the Company(the "Units") under the Company's Amended and Restated Profits Interest Incentive Plan or a successor equity plan ("Plan"). The Units will be subject to the terms of the Plan and the Unit Issuance Agreement between you and the Company evidencing the grant (the "Issuance Agreement") as well as the Company's Second Amended and Restated Operating Agreement (the "Operating Agreement"). The Units generally are intended to qualify as "profits interests" under Revenue Procedure93-27 and Revenue Procedure 2001-43 and thus shall not participate with respect to any Net Income or Net Loss of the Company prior to the issuance date of the Units (nor shall the Units be attributed any value of the assets of the Company held immediately prior to the issuance date of such Units). Subject to the terms of the Plan, the Issuance Agreement and the Operating Agreement, the Units will vest over a period of four (4) years in accordance with the following schedule: 25% of the Units shall vest after the first 12 months of continuous service from your Start Date and the balance of the Units shall vest in equal monthly installments over the next three (3) years of continuous service. The Units shall be subject to the "Participation Threshold" as described in the Plan. The Participation Threshold will be equal to or greater than the net fair value of the Company on the date of grant as determined by the Board. Please note, inasmuch as the Units are wholly subject to Board approval, the terms and conditions of the Plan, the Issuance Agreement and the Operating Agreement, nothing in this Offer Letter shall vary the terms of any Issuance Agreement signed by the Company and you and in the

event of a conflict between this Agreement and any Issuance Agreement, the terms of the Issuance Agreement shall govern.

This is a full-time position, and you will be expected to devote your full working time and ability to the performance of your duties. You will also be expected to give the Company your undivided loyalty, and to refrain from any activity that might interfere with your duties to the Company or create a potential or actual conflict of interest.

In your work for the Company, you will be prohibited from using or disclosing any confidential, proprietary or trade secret information of any former employer or other person to whom you have an obligation of confidentiality. Rather, you will be required to use only information that is generally known and used by persons with training and experience comparable to your own, is common knowledge in the industry or otherwise legally in the public domain, or is otherwise provided or developed by the Company. You agree that you will not bring onto Company premises or use in your work for the Company any unpublished documents or property belonging to any former employer or third party that you are not authorized to use and disclose. You represent further that you have disclosed to the Company any contract you have signed that might restrict your activities on behalf of the Company. By accepting employment with the Company, you are representing that you will be able to perform your job duties within these parameters.

This offer is not to be considered a contract guaranteeing employment for any specific duration. Your employment with the Company is "at-will" and, therefore, is not guaranteed. You may terminate your employment at any time and for any reason whatsoever. Likewise, the Company may terminate your employment at any time, with or without cause or prior warning. This provision for "at-will" employment supersedes all prior agreements and understandings concerning termination of employment, whether oral, written, or implied, and it can be changed or revoked only in a writing signed by you and the Chief Executive Officer or President of the Company.

In addition to the compensation package described above, you will be reimbursed for any Company-approved and IRS permitted out-of-pocket expenses (other than Company­ approved expenses which are charged by you on Company credit cards), in accordance with our policies.

As a condition of employment, you must agree to sign and abide by the Company's Employee Inventions and Non-Disclosure Agreement ("EINDA").

You also agree to comply with the Company's rules, policies and procedures as they are issued from time to time by the Company.

Before commencing employment, you must provide proof of your identity and authorization to work in the United States, and fill out a form 1-9 as required by federal immigration laws. Further, this offer is contingent upon your successful completion of a background check to the satisfaction of the Company.

To ensure the rapid and economical resolution of disputes that may arise in connection with your employment with the Company, you and the Company agree that any and all disputes, claims, or causes of action, in law or equity, including but not limited to statutory claims, arising from or relating to the enforcement, breach, performance, or interpretation of this Offer Letter, your employment with the Company, or the termination of your employment from the Company, will be resolved pursuant to the Federal Arbitration Act, 9 U.S.C. § I-16, and to the fullest extent permitted by law, by final, binding and confidential arbitration conducted in San Diego, California by JAMS, Inc. ("JAMS") or its successors by a single arbitrator, under JAMS' then applicable rules and procedures for employment disputes(which can be found at http://www.jamsadr.com/rules-clauses/, and which will be provided to you on request); provided that the arbitrator shall:(a) have the authority to compel adequate discovery for the resolution of the dispute and to award such relief as would otherwise be permitted by law; and (b) issue a written arbitration decision including the arbitrator's essential findings and conclusions and a statement of the award. You and the Company shall be entitled to all rights and remedies that either would be entitled to pursue in a court of law. Both you and the Company acknowledge that by agreeing to this arbitration procedure, you each waive the right to resolve any such dispute through a trial by jury or judge or administrative proceeding. The Company shall pay all filing fees in excess of those which would be required if the dispute were decided in a court of law, and shall pay the arbitrator's fee. Nothing in this Offer Letter intended to prevent either the Company or you from obtaining injunctive relief in court to prevent irreparable harm pending the conclusion of any such arbitration.

This Offer Letter and the EINDA sets forth the entire agreement between you and the Company with respect to the subject matter thereof. Once signed by you and an officer of the Company, this Offer Letter and the EINDA will become legally binding contracts, and will supersede all prior agreements, promises, and understandings between you and the Company.

This Offer Letter will be governed by and construed in accordance with the laws of the State of California. The validity or unenforceability of any provision of this Offer Letter, or any terms hereof, shall not affect the validity or enforceability of any other provision or term of this Offer Letter.

All payments made pursuant to this Offer Letter shall be subject to withholding of applicable income and employment taxes. The Company may withhold from any payments made under this Offer Letter all authorized or legally required deductions and withholdings, including but not limited to income, employment, and social insurance taxes. Nothing in this Agreement shall create any obligation on the part of the Company to indemnify, reimburse, gross up, or otherwise compensate you for any taxes, interest, penalties, costs, losses, damages, or expenses arising out of any violation of tax laws or any corresponding provision of law. Your signature below constitutes your agreement with the Company's employment terms and conditions.