The dominoes keep falling at Gilead Sciences. One week after reporting deaths in blood cancer patients, the Big Biotech has paused enrollment of magrolimab solid tumor trials following the FDA's request for a partial clinical hold on the anti-CD47 monoclonal antibody.
Four phase 2 studies sponsored by Gilead are affected by the partial hold. The trials are testing the drug candidate, which Gilead brought on board as part of its $4.9 billion acquisition of Forty Seven in 2020, in patients with solid tumors including colorectal and triple-negative breast cancers. Patients who are on magrolimab and “deriving clinical benefit” can re-consent to keep receiving the antibody.
Gilead is now “reviewing the benefit-risk of magrolimab across all ongoing trials” and “will provide an update on this assessment as soon as possible.” The biotech abandoned plans to develop the antibody in blood cancer last week in response to futility analyses and an increased risk of death.
At the time, Merdad Parsey, M.D., Ph.D., chief medical officer at Gilead, said the results highlighted the “complexity of treating blood cancer.” The latest update suggests treating solid tumors is no simpler for Gilead and magrolimab.
Magrolimab has suffered a series of setbacks since Gilead bought the drug candidate to add a non-cell therapy program to a blood cancer pipeline then skewed toward CAR-Ts from its earlier Kite Pharma acquisition. Gilead worked through a partial clinical hold early in 2022 but has run into bigger problems over the past seven months as magrolimab has failed phase 3 clinical trials and been linked to patient deaths.
The setbacks to magrolimab are part of a wider souring of attitudes toward CD47, the receptor that made waves around a decade ago as Irv Weissman, M.D., and his colleagues at Stanford University showed it plays a role in immune evasion. Evidence of CD47’s role in “don't eat me” signals led Gilead, AbbVie, Pfizer and others to invest in the target, although the pipeline is now a shadow of what it once was.
Solid tumors have been a rare source of positivity for CD47 in recent months, with ALX Oncology racking up a phase 2 win for its candidate last year. ALX, which previously stopped a pair of blood cancer trials, plans to start the phase 3 study in gastric cancer in the second half of the year. The question now is whether Gilead will keep giving chase.