---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-24-075211"
form_type: "8-K"
ticker: "CTMX"
cik: "0001501989"
company_name: "CytomX Therapeutics, Inc."
filed_at: "2024-03-22T23:59:59+00:00"
generated_at: "2026-06-04T09:01:23.470942+00:00"
event_type: "leadership"
sentiment: "neutral"
materiality_score: 0.35
calibrated_materiality_score: 0.35
confidence: "high"
source: SEC EDGAR
---

# CytomX appoints Zhen Su to Board; adopts amended bylaws for stockholder proposals

## Summary
- Zhen Su, M.D., M.B.A., appointed to Board as Class I director effective March 20, 2024, filling a vacancy.
- Dr. Su receives standard non-employee director compensation and an option to purchase 76,000 shares vesting over three years.
- Board adopted Amended and Restated Bylaws to modernize stockholder nomination and proposal procedures, including removal of 'acting in concert' provisions.
- Bylaw amendments effective immediately with clarifying and technical changes.

## SEC filing metadata
- accession: 0001193125-24-075211
- form_type: 8-K
- ticker: CTMX
- cik: 0001501989
- company_name: CytomX Therapeutics, Inc.
- filed_at: 2024-03-22T23:59:59+00:00
- event_type: leadership
- sentiment: neutral
- materiality_score: 0.35
- calibrated_materiality_score: 0.35
- confidence: high
- sec_items: 5.02, 5.03, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1501989/000119312524075211/0001193125-24-075211-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1501989/000119312524075211/d803852d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-24-075211
- JSON: https://secwatch.observer/filing/0001193125-24-075211.json
- Plain text: https://secwatch.observer/filing/0001193125-24-075211.txt

## Key facts
- Executive change
  Zhen Su was appointed as Class I director at CytomX Therapeutics, Inc..
  - Action: appointed
  - Role: Class I director
  source text: On March 20, 2024, Zhen Su, M.D., M.B.A., was appointed to the Board of Directors (the “Board”) of CytomX Therapeutics, Inc. (the “Company”), effective March 20, 2024, as a Class I director, with an initial term expiring at the Company’s 2025 annual meeting of stockholders, filling a vacancy.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1501989/000119312524075211/0001193125-24-075211-index.htm
- Governance Changes
  CytomX Therapeutics, Inc.: Amended and restated bylaws to modernize stockholder nomination and proposal procedures, remove 'acting in concert' provisions, and make clarifying changes (effective 2024-03-20).
  - Change: bylaw amendment
  - Effective: 2024-03-20
  source text: On March 20, 2024, the Board unanimously adopted Amended and Restated Bylaws of the Company (the bylaws, as so amended and restated, the “Amended and Restated Bylaws”), effective immediately, to, among other things, modernize and enhance certain disclosure and procedural requirements related to stockholder nominations of directors and submissions of stockholder proposals regarding other business at stockholder meetings, including removing the “acting in concert” provisions previously contained in the Company’s bylaws, as well as certain other clarifying, technical and conforming changes.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1501989/000119312524075211/0001193125-24-075211-index.htm

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.