Following Patient Deaths, Gilead Holds Off on 6 Zydelig Cancer Drug Trials

In light of patient deaths, Gilead Sciences Inc. is putting the brakes on six clinical trials involving the cancer drug Zydelig. European regulators reported elevated rates of death linked to infections in three Zydelig clinical trials. The U.S. Food and Drug Administration’s (FDA’s) alert followed. “The FDA is reviewing the findings of the clinical trials and will communicate new information as necessary,” the agency said. According to Law360, the trials were investigating the use of Zydelig combined with other cancer drugs to certain types of leukemia and lymphoma.

The European Medicines Agency said it would evaluate trial data “to assess whether the findings have any consequences for the authorized uses of Zydelig” Law360 reports. The exact number of deaths was not immediately reported. The EMA advises that patients be “carefully monitored” for signs of infection.

The identity of other drugs being used in combination with Zydelig during the trials is unclear. According to European regulators, at least one of the trials involved unapproved combinations of medicines.

The FDA approved Zydelig, also known as idelalisib, in 2014 to treat three types of blood cancers in relapsing patients. The label has a black box warning, the most serious type of warning, about potentially life-threatening side effects involving liver damage, diarrhea, intestinal perforation and pneumonitis.

Gilead says Zydelig is a first-in-class kinase inhibitor. The company called the cancer drug “a new therapy for patient populations with few other options” in its 2014 annual report.