ZNTL · Zentalis Pharmaceuticals, Inc.

Zentalis Pharmaceuticals announced a critical advancement in its lead program with the selection of 400mg once daily on a 5-days-on, 2-days-off schedule as the optimal monotherapy dose for azenosertib in Cyclin E1-positive platinum-resistant ovarian cancer patients. This decision stems from a prespecified interim analysis of DENALI Part 2a, which demonstrated a meaningful and clearly differentiated response rate at the 400mg dose compared to 300mg, alongside comparable safety profiles and improvements including a discontinuation rate due to adverse events approximately half that of DENALI Part 1b and no treatment-related deaths. The selected dose will carry forward into the ongoing DENALI Phase 2 trial, designed for potential accelerated approval with its seamless structure incorporating Part 2a data into the full dataset, and the confirmatory ASPENOVA Phase 3 trial aligned with FDA and set to initiate in Q2 2026. DENALI Part 2 has been expanded with a new Part 2c cohort to include approximately 40 patients previously treated with taxane-containing regimens, aligning the study with the evolving PROC treatment landscape; Part 2b is expanding enrollment at the selected dose to up to 100 patients. The company anticipates completing enrollment across all DENALI Part 2 cohorts and delivering topline data by year-end 2026. This progress is supported by a cash position of $245.9 million as of December 31, 2025, funding operations into late 2027, enabling focus on registration-intent studies and pre-commercial activities including companion diagnostic development for Cyclin E1-positive patients, who represent about 50% of the PROC population.