BioPharma, Pharma

FDA gives Gilead reprieve on partial hold for cancer drug studies

An FDA safety review has cleared Gilead Sciences to resume five clinical trials that were placed under a partial hold in January. The experimental Gilead drug, magrolimab, is part of a class of cancer immunotherapies that address a hot target for the field.


The FDA has lifted the partial hold placed on five Gilead Sciences clinical trials, clearing the pharmaceutical company to resume tests of an experimental cancer immunotherapy. However, the partial hold remains on two additional studies that were also paused shortly after the initial FDA action was announced in January.

The partial hold on tests of the drug, magrolimab, cited an “apparent imbalance” in unexpected serious adverse reactions between the studies, Gilead said in January. The lift of the partial hold was announced after the market close on Monday. Gilead did not provide additional details on the nature of this safety problem, saying only that the regulator removed the partial hold after reviewing safety data from each trial.

Magrolimab is an antibody designed to block CD47, a protein on the surface of cancer cells that sends a signal preventing macrophages, a type of immune cell, from recognizing tumors as a target. The drug joined the Gilead pipeline via the $4.9 billion acquisition of cancer drug developer Forty Seven in 2020.

The partial hold covered three Phase 3 studies in myelodysplastic syndrome, acute myeloid leukemia, and unfit acute myeloid leukemia. Also covered was a Phase 1b test in myelodysplastic syndrome and a Phase 2 clinical trial in myeloid malignancies. The agency later expanded the partial hold to include two other studies, in diffuse large B-cell lymphoma and multiple myeloma.

The partial hold prevented Gilead from enrolling any new patients in the clinical trials, though those already participating were able to continue to receive the experimental drug. Gilead said it is now working with regulatory bodies to re-open enrollment of magrolimab studies that were placed on a voluntary hold outside of the U.S. The company added that it’s also working with the FDA to resolve the partial hold on the remaining two studies. Clinical trials evaluating the Gilead drug in solid tumors were unaffected by the partial hold. Gilead said it expects the first interim data from pivotal tests of magrolimab will be reported in 2023.

Clearance to resume the magrolimab clinical trials keeps Gilead in the race to bring to patients a CD47 inhibitor for cancer. Pfizer added its contender via its $2.3 billion Trillium Therapeutics acquisition last year. AbbVie is also in the mix via its partnership with Shanghai-based I-Mab. And nearly a year ago, Arch Oncology closed a $105 million financing round to support clinical development of its CD47 inhibitor.

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