NEW YORK – Gilead Sciences said on Tuesday that the US Food and Drug Administration has placed a partial hold on studies involving its investigational anti-CD47 agent magrolimab and the chemotherapy azacitidine (Bristol Myers Squibb's Vidaza), a combination the firm is evaluating for acute myeloid leukemia and myelodysplastic syndrome, among other cancers.
In accordance with the FDA's clinical hold, Gilead will stop screening and enrolling patients to any of its studies that combine the two agents. Patients who are already enrolled in these trials, however, can continue receiving the combination treatment under close monitoring.
The agency placed the partial clinical hold on these studies, according to the Foster City, California-based firm, after citing an "apparent imbalance in investigator-reported suspected unexpected serious adverse reactions between study arms." Gilead said it has not identified any clear trends in adverse reactions or new safety signals but will analyze additional data to address the FDA's concerns.
The clinical hold affects five magrolimab clinical trials, including three Phase III trials and two earlier-phase trials. One affected study, ENHANCE-2, is comparing the activity of magrolimab plus azacitidine versus physician's choice of venetoclax (Abbvie/Genentech's Venclexta) with azacitidine or intensive chemo in treatment-naïve TP53-mutated AML patients.
Ongoing studies of magrolimab without azacitidine are not affected by the clinical hold. In those studies, Gilead continues to evaluate the CD47-targeted monoclonal antibody, which came into its pipeline with the $4.9 billion acquisition of biotech firm Forty Seven during the spring of 2020.