# EDGAR Filing Document

**Accession Number:** 0001654058
**File Stem:** 0001567619-23-001930
**Filing Date:** 2023-2
**Character Count:** 7108
**Document Hash:** 202e47f3306d219bfbeffdda75207136
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001567619-23-001930.hdr.sgml**: 20230206

**ACCESSION NUMBER**: 0001567619-23-001930

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20230202

**FILED AS OF DATE**: 20230206

**DATE AS OF CHANGE**: 20230206

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** McCarthy Sean A.
- **CENTRAL INDEX KEY:** 0001654058

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-37587
- **FILM NUMBER:** 23591307

**MAIL ADDRESS:**
- **STREET 1:** 343 OYSTER POINT BLVD.
- **STREET 2:** SUITE 100
- **CITY:** SOUTH SAN FRANCISCO
- **STATE:** CA
- **ZIP:** 94080
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** CytomX Therapeutics, Inc.
- **CENTRAL INDEX KEY:** 0001501989
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **IRS NUMBER:** 273521219
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 151 OYSTER POINT BLVD.
- **STREET 2:** SUITE 400
- **CITY:** SOUTH SAN FRANCISCO
- **STATE:** CA
- **ZIP:** 94080
- **BUSINESS PHONE:** 650.515.3185

**MAIL ADDRESS:**
- **STREET 1:** 151 OYSTER POINT BLVD.
- **STREET 2:** SUITE 400
- **CITY:** SOUTH SAN FRANCISCO
- **STATE:** CA
- **ZIP:** 94080

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## FORM 4

### STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

[ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

[ ] Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>McCarthy Sean A.<br><sub>(Last) (First) (Middle)</sub><br>C/O CYTOMX THERAPEUTICS, INC.<br>151 OYSTER POINT BLVD., STE. 400<br><sub>(Street)</sub><br>SOUTH SAN FRANCISCO, CA 94080<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2023-02-02 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [ ] 10% Owner<br>[X] Officer (give title below) [ ] Other (specify below)<br>_CEO_ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>CytomX Therapeutics, Inc. [ CTMX ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[X] Form filed by One Reporting Person<br>[ ] Form filed by More than One Reporting Person |

---

## Table I - Non-Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | 3. Transaction Code (V) | 3. Transaction Code (V) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | Code | V | Amount | (A) or (D) | Price | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| Common Stock | 2023-02-02 |  | A |  | 105000<sup>(1)</sup> | A | $0 | 395942<sup>(2)</sup> | D |  |
| Common Stock |  |  |  |  |  |  |  | 93158 | I | See footnote<sup>(3)</sup> |

---

## Table II - Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | 4. Transaction Code (V) | 4. Transaction Code (V) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 6. Date Exercisable and Expiration Date | 6. Date Exercisable and Expiration Date | 7. Title and Amount of Underlying Securities | 7. Title and Amount of Underlying Securities | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | Code | V | (A) | (D) | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| Stock Option (Right to Buy) | $2.59 | 2023-02-02 |  | A |  | 315000 |  | <sup>(4)</sup> | 2033-02-01 | Common Stock | 315000 | $0.00 | 315000 | D |  |
| Performance Stock Units (PSUs) | <sup>(5)</sup> | 2023-02-02 |  | A |  | 300000 |  | <sup>(5)</sup> | <sup>(5)</sup> | Common Stock | 300000 | $0.00 | 300000 | D |  |

---

### Footnotes:

(1) Constitute restricted stock units ("RSUs") for which the Reporting Person is entitled to receive one (1) share of Common Stock for each RSU upon vesting. 1/3rd of the RSUs vest annually on Febrary 2 of each year, with the first 1/3rd vesting on February 2, 2024, subject to the Reporting Person continuing as a service provider through each such date.

(2) Includes 180,000 RSUs.

(3) Shares held by Sean A. McCarthy 2018 Trust, of which Reporting Person is trustee.

(4) 1/48th of the shares subject to the option vest on each monthly anniversary measured from February 2, 2023 (the "Vesting Commencement Date"), such that 100% of the shares subject to the option will be fully vested and exercisable on the fourth anniversary of the Vesting Commencement Date, subject to the Reporting Person continuing as a service provider through each such date.

(5) Each Performance-Based Restricted Stock Unit ("PSU") represents a contingent right to receive one (1) share of Common Stock upon vesting. 1/2 of the PSUs vest upon the achievement of each of two clinical milestones, subject to the Reporting Person continuing as a service provider through each such date.

**Signature:** /s/ Lloyd Rowland, as Attorney-in-Fact for Sean A. McCarthy  
**Date:** 2023-02-06

### Remarks:

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

**Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.**