Zentalis Stock Up as FDA Lifts Partial Hold on Cancer Drug Studies

Core Viewpoint - Zentalis Pharmaceuticals' shares rose by 13.6% following the FDA's decision to lift the partial clinical hold on three studies of its lead product candidate, azenosertib, which is being investigated for various cancer indications [1][3]. Company Developments - Azenosertib is a potentially first-in-class oral WEE1 inhibitor being studied as both a monotherapy and in combination with other therapies for solid tumors and ovarian cancer [2]. - The FDA has allowed Zentalis to resume enrollment in all ongoing azenosertib clinical studies without changes to the clinical development plan, with the company planning to restart study activities promptly [3]. - Zentalis has completed enrollment in cohort 1b of the DENALI study, with overall efficacy and safety data expected to be announced later in 2024 [8]. Historical Context - In June 2024, the FDA imposed a partial clinical hold on azenosertib studies due to two patient deaths in the DENALI study, which significantly impacted Zentalis' share price [6][7]. - The company also discontinued the development of a combination therapy involving its BCL-2 inhibitor, ZN-d5, due to unsatisfactory efficacy data [7]. Future Plans - Zentalis plans to present data from the ZN-c3-001 and MAMMOTH studies later in the year, with the MAMMOTH study evaluating azenosertib in combination with GSK's PARP inhibitor Zejula [8][9]. - The company is scheduled to present azenosertib monotherapy data and updates on the clinical development program at an upcoming medical conference [10]. Market Performance - Year to date, Zentalis' shares have decreased by 75.7%, contrasting with the industry's growth of 0.5% [5].