---
schema_version: "secwatch.filing_event.v1"
accession: "0001628280-25-012899"
form_type: "8-K"
ticker: "ZNTL"
cik: "0001725160"
company_name: "Zentalis Pharmaceuticals, Inc."
filed_at: "2025-03-17T23:59:59+00:00"
generated_at: "2026-05-24T15:54:45.058335+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.8
calibrated_materiality_score: 0.8
confidence: "high"
source: SEC EDGAR
---

# Zentalis reports azenosertib ORR ~35% and mDOR 6.3 months in Cyclin E1+ PROC; Part 2 initiation on track for 1H2025

## Summary
- Azenosertib demonstrated ORR of 34.9% (15/43) in response-evaluable Cyclin E1+ PROC patients; mDOR 6.3 months (95% CI: 2.7–NE) as of Jan 13, 2025 cutoff.
- Cyclin E1 overexpression by IHC identified as predictive biomarker; ~50% of PROC patients overexpress Cyclin E1.
- Safety profile consistent; most common TRAEs were GI toxicities and fatigue; 21.6% discontinued due to TRAEs.
- Initiation of DENALI Part 2 in 1H 2025 on track; registration-intent topline data expected by year end 2026.
- Preclinical data show synergistic antitumor effects of azenosertib combined with microtubule inhibitor-based ADCs.

## SEC filing metadata
- accession: 0001628280-25-012899
- form_type: 8-K
- ticker: ZNTL
- cik: 0001725160
- company_name: Zentalis Pharmaceuticals, Inc.
- filed_at: 2025-03-17T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.8
- calibrated_materiality_score: 0.8
- confidence: high
- sec_items: 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1725160/000162828025012899/0001628280-25-012899-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1725160/000162828025012899/zntl-20250315.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001628280-25-012899
- JSON: https://secwatch.observer/filing/0001628280-25-012899.json
- Plain text: https://secwatch.observer/filing/0001628280-25-012899.txt

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