FDA Grants Breakthrough Therapy Designation to Magrolimab for Treatment of MDS

The FDA has granted breakthrough therapy designation to magrolimab for the treatment of newly diagnosed myelodysplastic syndrome (MDS), according to Gilead Sciences, the developer of the agent.¹

The designation for magrolimab was granted based on positive results observed in an ongoing phase 1b study, which is evaluating magrolimab in combination with azacytidine (Onureg) in previously untreated intermediate, high, and very high-risk MDS.

According to data presented at the 2020 European Hematology Society Congress, 30 (91%) of 33 evaluable patients treated with magrolimab plus azacitidine achieved an objective response, including 42% who achieved a complete remission (CR).² Patient responses deepened over time, with a 56% CR rate observed in patients with 6 months or more of follow-up.

Median time to initial response was rapid, at 1.9 months. Further, the median duration of response has not been reached, with a median follow-up of 5.8 months. The median overall survival (OS) has also not been reached (range, 1.4 to 18.3 months) with a 6-month OS estimate of 100%.

The combination of magrolimab plus azacitidine was also found to be generally well-tolerated. Common treatment-related AEs or AEs of interest were anemia (44%), fatigue (18%), infusion reaction (18%), neutropenia (8%), and thrombocytopenia (5%). No treatment-related febrile neutropenia was observed. Moreover, no maximum tolerated dose was reached and no patients with MDS discontinued treatment due to a treatment related adverse event.

“The breakthrough therapy designation recognizes the potential for magrolimab to help address a significant unmet medical need for people with MDS and underscores the transformative potential of Gilead’s immuno-oncology therapies in development,” Merdad Parsey, MD, PhD, Chief Medical Officer at Gilead Sciences, said in a press release.

Currently, magrolimib is being studied in patients with previously untreated higher risk MDS in the double-blind, placebo-controlled, randomized phase 3 ENHANCE trial. The trial is designed to evaluate the safety and efficacy of magrolimab in combination with azacitidine, as measured by CR as well as duration of CR.

Notably, magrolimab is an investigational agent and has not been approved anywhere globally. However, the first-in-class, investigational anti-CD47 monoclonal antibody has been granted fast track designation by the FDA for the treatment of MDS, acute myeloid leukemia, diffuse large B-cell lymphoma, and follicular lymphoma. Magrolimab has also been granted orphan drug designation by the FDA for MDS and AML and by the European Medicines Agency for AML.

Reference:

1. Gilead’s Magrolimab, an Investigational Anti-CD47 Monoclonal Antibody, Receives FDA Breakthrough Therapy Designation for Treatment of Myelodysplastic Syndrome [news release]. Foster City, California. Published September 15, 2020. Accessed September 15, 2020. http://investors.gilead.com/news-releases/news-release-details/gileads-magrolimab-investigational-anti-cd47-monoclonal-antibody

2. David S, Malki MA, Asch A, et al. THE FIRST-IN-CLASS ANTI-CD47 ANTIBODY MAGROLIMAB COMBINED WITH AZACITIDINE IS WELL-TOLERATED AND EFFECTIVE IN MDS PATIENTS: PHASE 1B RESULTS. Presented at the 2020 European Hematology Society Congress. Abstract S187.