---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-25-179463"
form_type: "8-K"
ticker: "CTMX"
cik: "0001501989"
company_name: "CytomX Therapeutics, Inc."
filed_at: "2025-08-13T23:59:59+00:00"
generated_at: "2026-05-17T13:54:55.317681+00:00"
event_type: "other_material"
sentiment: "negative"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# CytomX reports Grade 5 adverse event in CX-2051 Phase 1 trial; FDA notified, study continues

## Summary
- Single Grade 5 acute kidney injury occurred in patient with solitary kidney; event believed secondary to nausea, vomiting, diarrhea.
- Safety Review Committee convened July 14, 2025, supported continued study execution and enrollment.
- FDA notified on July 18, 2025; company aware on July 11, 2025.
- CX-2051 dose expansions at 7.2, 8.6, and 10 mg/kg each enrolled ~20 patients as planned.
- Phase 1 data update expected by Q1 2026.

## SEC filing metadata
- accession: 0001193125-25-179463
- form_type: 8-K
- ticker: CTMX
- cik: 0001501989
- company_name: CytomX Therapeutics, Inc.
- filed_at: 2025-08-13T23:59:59+00:00
- event_type: other_material
- sentiment: negative
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 8.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1501989/000119312525179463/0001193125-25-179463-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1501989/000119312525179463/d925542d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-25-179463
- JSON: https://secwatch.observer/filing/0001193125-25-179463.json
- Plain text: https://secwatch.observer/filing/0001193125-25-179463.txt

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