Zentalis reports 39% response rate in Phase 1b ovarian cancer trial, optimal dose shows 50% ORR

Filed May 21, 2026 · Period ending May 21, 2026 · ~1 min read

Key Changes

• high

  Phase 1b MUIR trial of azenosertib plus paclitaxel showed 39.1% overall response rate and 7.3-month median progression-free survival in 46 platinum-resistant ovarian cancer patients, with results to be presented at ASCO 2026.

  Press Release, May 21, 2026 view on EDGAR →
• high

  Optimal 250mg intermittent dose cohort achieved 50% response rate including one complete response, with 9.2-month median duration of response in 12 patients, establishing preferred dose for future development.

  Press Release, May 21, 2026 view on EDGAR →
• medium

  Drug showed similar efficacy in Cyclin E1-positive and negative patients (41.4% vs 35.7% response rates), suggesting broader patient population may benefit beyond biomarker-selected groups when combined with chemotherapy.

  Press Release, May 21, 2026 view on EDGAR →