FDA Places Zentalis’ Cancer Drug Studies on Partial Hold After Patient Deaths
June 18, 2024 – The U.S. Food and Drug Administration (FDA) has placed three studies of Zentalis Pharmaceuticals’ cancer drug, azenosertib, on partial clinical hold following the deaths of two trial participants, Zentalis Pharmaceuticals announced on Tuesday.
Shares of Zentalis Pharmaceuticals dropped approximately 26% to $6.22 in early trading following the announcement. The drug candidate, azenosertib, was being evaluated in early-stage studies against solid tumors and in mid-stage studies for ovarian and uterine cancers.
Despite the partial hold, dosing for participants already enrolled in the studies will continue, though further enrollments in the mid-stage studies have been paused. The FDA’s decision follows the deaths of two patients in the ovarian cancer study due to presumed blood-related infections associated with the treatment.
“We don’t think this is the end for azenosertib,” said Oppenheimer analyst Matthew Biegler, noting that the hold is likely resolvable with enhanced patient monitoring and preventative measures.
Zentalis CEO Kimberly Blackwell emphasized that resolving the partial clinical hold is crucial for continuing azenosertib’s development as a monotherapy. Other studies testing the drug in combination therapies are allowed to proceed.
Azenosertib belongs to a class of drugs that inhibit the WEE1 protein, which may be overexpressed in some cancer cells. Zentalis plans to share additional efficacy and safety data from the ovarian cancer trial later this year and is working with the FDA to address the clinical hold.