Zentalis Pharmaceuticals Advances Azenosertib Toward FDA Accelerated Approval With Pivotal Dose Selection

Zentalis Pharmaceuticals has locked in a pivotal dose for azenosertib and initiated a Phase 3 confirmatory trial, positioning the WEE1 inhibitor on a dual-track regulatory path that plant heads and QA directors should begin mapping against manufacturing scale-up timelines now. The 400mg once-daily 5:2 schedule was selected following a pre-specified interim analysis from DENALI Part 2a, with a topline readout from the full DENALI Part 2 cohort expected by year-end 2026.

The interim data supporting dose selection showed a discontinuation rate due to adverse events at roughly half the rate observed in DENALI Part 1b, with no treatment-related deaths, a benefit-risk profile the company characterised as clearly differentiated. DENALI Part 2 is designed to support a potential FDA accelerated approval pathway in Cyclin E1-positive platinum-resistant ovarian cancer (PROC), subject to regulatory review and data outcomes. Zentalis has simultaneously dosed the first patient in ASPENOVA, its Phase 3 confirmatory trial in Cyclin E1-positive PROC, which is structured to support conversion to full approval and ex-US registrations.

For regulatory affairs leads, the architecture here is deliberate: an accelerated approval submission anchored to DENALI Part 2 response-rate data, with ASPENOVA running concurrently as the confirmatory vehicle required under 21 CFR Part 312 post-approval commitments. Zentalis has also expanded DENALI Part 2 to include Part 2c, a new cohort of approximately 40 patients previously treated with a taxane-containing regimen, to maintain alignment between the study population and the current treatment landscape as standard-of-care evolves.

On the manufacturing side, Zentalis stated it has initiated pre-commercial launch preparedness activities following dose selection, including scaling manufacturing capacity and advancing companion diagnostic market development for the Cyclin E1 biomarker. Operations teams supporting commercial readiness will need to track the DENALI Part 2 topline readout as the primary trigger for accelerated approval submission timing.

Zentalis reported $211.8 million in cash, cash equivalents, and marketable securities as of March 31, 2026, providing a stated runway into late 2027 to fund execution of these milestones. The company also flagged strategic expansion interest into platinum-sensitive and first-line maintenance ovarian cancer settings, as well as additional tumour types and combination regimens, though no timelines were provided for those programmes.

The DENALI Part 2 topline readout, expected before the end of 2026, will be the first measurable checkpoint determining whether an accelerated approval submission moves forward.

Source: Zentalis Pharmaceuticals via GlobeNewswire, May 12, 2026.