Gilead to end PhIII blood disorder trial for CD47 antibody magrolimab due to ‘futility’

Gilead will scrap one of three Phase III trials for magrolimab, the anti-CD47 drug at the heart of its $4.9 billion acquisition of Forty Seven three years ago, while carrying on with the other two.

In a late Friday statement, Gilead attributed the decision to “futility based on a planned analysis.” The trial being stopped, ENHANCE, was studying the use of magrolimab plus a type of chemotherapy called azacitidine (Vidaza) in patients with higher-risk myelodysplastic syndromes, or MDS.

On the safety front, the company said the data appear in line with expectations for both magrolimab and this patient population. It will now work with investigators to decide on next steps for patients enrolled in the trial.

Merdad Parsey

“The health and well-being of patients are our top priorities and while this is disappointing news it confirms the challenges of treating HR-MDS, where no new class of treatments have been approved in nearly 20 years,” said chief medical officer Merdad Parsey in a statement.

Two other similar trials — ENHANCE-2 in first-line acute myeloid leukemia with TP53 mutations and ENHANCE-3 in first-line AML patients who are unfit for standard treatment — will continue. A spokesperson added that screening and enrollment for those non-MDS studies “continues as planned,” with an update expected in 2024.

The latest setback for magrolimab comes after a series of delays and disappointments. When Gilead first acquired Forty Seven — on the promise of blocking the CD47 “don’t eat me” signal that cancer often co-opts to evade immune attack — it saw the potential of filing for accelerated approval in late 2021 based on Phase Ib data.

Then in January 2022, the FDA put a slate of magrolimab trials, including all three ENHANCE trials, on partial hold after investigators flagged an “apparent imbalance” on serious side effects but lifted the hold a few months later.

ENHANCE was originally slated for an interim readout in 2023. It was designed to enroll about 520 patients in total, tracking both complete response rate and overall survival as the primary endpoints.

For the MDS indication, Gilead had secured a breakthrough therapy designation from the FDA and PRIME designation for priority medicines from the EMA.

Editor’s note: Kyle LaHucik contributed reporting to this story.

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