---
schema_version: "secwatch.filing_event.v1"
accession: "0001725160-23-000119"
form_type: "8-K"
ticker: "ZNTL"
cik: "0001725160"
company_name: "Zentalis Pharmaceuticals, Inc."
filed_at: "2023-05-26T23:59:59+00:00"
generated_at: "2026-06-14T13:10:24.979695+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# Zentalis announces positive Phase 1b data for azenosertib; plans Phase 3 trial in Cyclin E1+ ovarian cancer

## Summary
- Azenosertib + paclitaxel achieved 50% ORR (7.4 months mPFS) in platinum-resistant ovarian cancer.
- Cyclin E1+ tumors showed 40% ORR vs 8.3% in Cyclin E1- (HR=0.37; p=0.0078).
- Well tolerated; Grade ≥3 AEs: thrombocytopenia (27.5%), neutropenia (25.5%), anemia (15.7%), fatigue (9.8%).
- Phase 3 study of azenosertib in combination with chemotherapy in Q1 2024.

## SEC filing metadata
- accession: 0001725160-23-000119
- form_type: 8-K
- ticker: ZNTL
- cik: 0001725160
- company_name: Zentalis Pharmaceuticals, Inc.
- filed_at: 2023-05-26T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1725160/000172516023000119/0001725160-23-000119-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1725160/000172516023000119/zntl-20230525.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001725160-23-000119
- JSON: https://secwatch.observer/filing/0001725160-23-000119.json
- Plain text: https://secwatch.observer/filing/0001725160-23-000119.txt

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