Dr Kin on the Withdrawal of Belantamab Mafodotin in R/R Multiple Myeloma

Andrew Kin, MD, medical oncologist, Karmanos Cancer Institute, discusses the withdrawal of the United States marketing authorization of belantamab mafodotin-blmf (Blenrep) for the treatment of patients with relapsed/refractory multiple myeloma who have received at least 4 prior therapies, including an anti-CD38 monoclonal antibody, a proteasome inhibitor, and an immunomodulatory agent.

In August 2020, the FDA granted accelerated approval to the antibody-drug conjugate (ADC) in this indication. However, in November 2020, GlaxoSmithKline plc initiated the process to withdraw the United States marketing authorization for belantamab mafodotin for the treatment of this population. The decision was made following a request from the FDA, based on results from the phase 3 DREAMM-3 trial (NCT04162210), which did not meet its primary end point of progression-free survival (PFS) for belantamab mafodotin compared with the combination of pomalidomide (Pomalyst) plus low-dose dexamethasone.

Belantamab mafodotin is a BCMA-targeted ADC linking a microtubule-disrupting chemotherapy agent to a monoclonal antibody, that had generated similar response rates to what has previously been seen with other drugs in the penta-refractory space, Kin says. Although belantamab mafodotin is associated with unique corneal-related toxicities, the ocular adverse effects were not related to the decision to remove the agent from its indication in multiple myeloma, Kin explains.

DREAMM-3 served as head-to-head comparison for belantamab mafodotin vs the combination of pomalidomide plus low-dose dexamethasone, which is a highly active regimen in this setting, Kin notes. Findings from the confirmatory trial showed that the median PFS for patients treated with belantamab mafodotin was 11.2 months vs 7.0 months with pomalidomide plus dexamethasone (HR, 1.03; 95% CI, 0.72-1.47). Although these outcomes represented a numerical improvement for belantamab mafodotin, the findings were not statistically superior, Kin emphasizes.

Although belantamab mafodotin has been removed from the market, the agent is currently being explored in ongoing clinical trials, which could pave the way for future FDA approvals, Kin concludes.