EMA Review of Belantamab Mafodotin (Blenrep) for the Treatment of Adult Patients with Relapsed/Refractory Multiple Myeloma

On August 25, 2020, a marketing authorization valid through the European Union was issued for belantamab mafodotin monotherapy for the treatment of multiple myeloma (MM) in adult patients who have received at least four prior therapies, whose disease is refractory to at least one proteasome inhibitor (PI), one immunomodulatory agent (IMiD), and an anti-CD38 monoclonal antibody (mAb), and who have demonstrated disease progression on the last therapy. Belantamab mafodotin is an antibody-drug conjugate that combines a mAb, which binds specifically to B-cell maturation antigen, with maleimidocaproyl monomethyl auristatin F, which is a cytotoxic agent. It was evaluated in Study 205678 (DREAMM-2), an open-label, two arm, phase II, multicenter study in patients with MM who had relapsed following treatment with at least three prior therapies, who were refractory to an IMiD, a PI, and an anti-CD38 mAb alone or in combination. Patients were randomized to receive 2.5 mg/kg (n = 97) or 3.4 mg/kg (n = 99) belantamab mafodotin by intravenous infusion every 3 weeks until disease progression or unacceptable toxicity. Belantamab mafodotin achieved an overall response rate (ORR) of 32% (97.5% confidence interval [CI]: 22-44) with a median duration of response (DoR) of 11 months (95% CI: 4.2 to not reached). The most frequently (>= 20%) reported adverse reactions grades 3-4 with belantamab mafodotin were keratopathy (31%), thrombocytopenia (22%), and anemia (21%). With regard to the corneal risks associated with belantamab mafodotin, patients would need to undergo specific ophthalmic examinations so that any findings can be promptly and adequately managed. The scientific review concluded that a 32% ORR and a median DoR of 11 months observed with belantamab mafodotin was considered clinically meaningful. Given the manageable toxicity profile and considering that belantamab mafodotin has a mechanism of action that is different from that of authorized treatments in this group of highly pretreated patients whose disease is refractory to three classes of agents, the benefit risk for belantamab mafodotin monotherapy was considered positive, although the efficacy and safety evidence were not as comprehensive as normally required. Implications for Practice Belantamab mafodotin (Blenrep, GlaxoSmithKline, St. Louis, MO, U.S.A) was approved in the European Union as monotherapy for the treatment of adult patients with refractory/relapsed multiple myeloma. Belantamab mafodotin resulted in durable response in highly pretreated patients whose disease is refractory to three classes of agents. Belantamab mafodotin is a monoclonal antibody against B-cell maturation antigen conjugated with the potent antimitotic agent maleimidocaproyl monomethyl auristatin. This is the first monoclonal antibody to target this antigen in multiple myeloma, which represents a true novelty from a pharmacological point of view.