Gilead on Thursday disclosed that Trodelvy, the antibody-drug conjugate that is a key part of the drugmaker’s oncology business, failed a Phase 3 study after it didn’t show an improvement in patient survival.
There were more deaths from adverse events in the group of patients getting Trodelvy compared to the chemotherapy control arm, Gilead said in a press release, primarily related to complications like infections from low white blood cell counts.
Gilead said it will further investigate the data, though it declined to answer questions about the deaths. The drug has a boxed warning for “severe or life-threatening neutropenia,” which is caused by a deficiency in a type of white blood cells.
The trial failure is a blow for Gilead, which has called Trodelvy a “cornerstone” of its cancer portfolio that last year brought in $1.1 billion in sales. The study was meant to serve as the confirmatory trial for Trodelvy’s accelerated approval in the US in locally advanced or metastatic urothelial cancer, a form of bladder cancer. The failed trial means the approval could be pulled by the FDA.
“Gilead is continuing to analyze the data and will discuss the results and next steps with the FDA,” the company said in an email to Endpoints News.
The drug is also approved for use in two types of breast cancer. In January, Gilead said the treatment failed a Phase 3 study in lung cancer, and will be detailing data from that trial on Friday at the American Society of Clinical Oncology annual meeting.
Gilead said full data from the bladder cancer study will be presented at an upcoming medical meeting.