Zentalis Pharmaceuticals is a clinical-stage biopharmaceutical company with a single drug candidate: azenosertib, an oral WEE1 inhibitor targeting ovarian cancer. WEE1 is a kinase involved in DNA damage repair; blocking it forces cancer cells into division before they can repair DNA, causing cell death. Zentalis is focused on a biomarker-defined subset of patients — women with platinum-resistant ovarian cancer whose tumors overexpress the Cyclin E1 protein, which makes cells especially sensitive to WEE1 inhibition. The lead program is the DENALI Phase 2 trial, where Part 1b data showed an objective response rate of ~35% in Cyclin E1-positive patients. Dose selection from Part 2a is expected in the first half of 2026, with a full Part 2 topline readout anticipated by year-end 2026. Zentalis has also aligned with the FDA on a Phase 3 confirmatory trial (ASPENOVA) versus standard-of-care chemotherapy, planned to begin in the first half of 2026. The FDA has granted Fast Track Designation for this indication. Zentalis has no approved products and generates no revenue, relying entirely on capital markets to fund development. The company outsources all manufacturing to CMOs and completed a ~40% workforce reduction in 2025, ending the year with 106 employees, to extend its cash runway. If approved, azenosertib would be a specialty oral oncology drug sold to a biomarker-selected patient population identified via a companion diagnostic test currently in development.