Gilead ends blood cancer path for troubled CD47 med after increased risk of death detected

Facing a full FDA clinical hold on a clutch of studies, Gilead is ending development of magrolimab in blood cancer after an “increased risk of death” was observed in a late-stage trial for the med.

The news is the latest blow to the program, picked up in the $4.9 billion acquisition of Forty Seven in 2020.

Gilead announced that the phase 3 ENHANCE-3 study is being discontinued in acute myeloid leukemia based on the recommendation of the independent data monitoring committee that had been reviewing top-line data from a planned interim analysis, according to a Wednesday release. The analysis showed an increased risk of death when adding magrolimab to the chemotherapy azacitidine and Genentech/AbbVie’s Venclexta, as well as futility. The deaths were caused by infections and respiratory failure, Gilead said.

The FDA has now placed a full clinical hold on the anti-CD47 antibody in myelodysplastic syndromes (MDS) and AML, plus related expanded access programs.

“The complexity of treating blood cancer is highlighted in these results,” said Gilead Chief Medical Officer Merdad Parsey, M.D., Ph.D., in the release. “We are incredibly grateful to all the patients and investigators for their participation in the ENHANCE studies.”

Gilead will end all development of the therapy in blood cancer, setting the asset firmly back to phase 2 with tests in breast, lung and gastrointestinal cancers, and other solid tumors. The company is reviewing safety data across all the ongoing solid tumor trials and plans to provide an update soon.

Patients in ENHANCE-3 will discontinue magrolimab and the company is working with investigators to figure out next steps. A sub-analysis of efficacy and safety is ongoing, Gilead said. This information will be shared with regulatory authorities and at an upcoming medical meeting or in a peer-reviewed journal.

Top-line results from all pivotal studies of magrolimab, which includes ENHANCE 1 through 3, will be shared “shortly,” according to Gilead.

The phase 3 ENHANCE-2 trial was stopped in September 2023 after an ad-hoc analysis showed that magrolimab was unlikely to improve survival in patients with AML. Prior to that, a test in MDS was also halted and the FDA placed a partial clinical hold on the late-stage AML program.

Gilead's shares were trading down 4% at $74.64 by 11:13 am ET on Wednesday morning.