Zentalis Selects 400mg Azenosertib Dose for Pivotal Phase 2 and 3 Trials in Ovarian Cancer

Zentalis Pharmaceuticals announced the selection of 400mg QD on a 5-days-on, 2-days-off schedule as the optimal monotherapy dose for azenosertib in Cyclin E1-positive platinum-resistant ovarian cancer (PROC). This decision follows a prespecified interim analysis of Part 2a of the Phase 2 DENALI trial, which showed a clearly differentiated response rate for the 400mg dose over the 300mg dose, alongside a comparable safety profile and improved discontinuation rates. The company plans to carry this dose forward into the ongoing registration-intended DENALI trial and the confirmatory Phase 3 ASPENOVA trial, the latter of which is expected to initiate in Q2 2026. Zentalis also expanded the DENALI study to include Part 2c, a new cohort for patients previously treated with taxane-containing regimens, also launching in Q2 2026. A topline readout for all DENALI Part 2 cohorts is expected by year-end 2026 to support a potential accelerated approval. Financially, Zentalis reported $245.9 million in cash as of year-end 2025, providing a runway into late 2027.