GSK’s Belantamab Mafodotin Shows Promise for Relapsed or Refractory Multiple Myeloma

GlaxoSmithKline’s investigational antibody-drug conjugate, belantamab mafodotin (GSK2857916), demonstrated a clinically meaningful overall response rate in hard-to-treat multiple myeloma patients in a Phase 2 trial, with the trial meeting its primary goal.

Findings from the open-label DREAMM-2 study (NCT03525678) — which is assessing the treatment as a fourth-line or later therapy — will be presented at an upcoming scientific meeting.

“I am pleased with the results of the DREAMM-2 study and excited about what these data could mean for patients with multiple myeloma who have exhausted other lines of treatment,” Hal Barron, chief scientific officer and president of research and development at GSK, said in a press release.

Belantamab mafodotin is an antibody-drug conjugate, composed of an anti-BCMA monoclonal antibody bound to auristatin F, a molecule that causes cell death. BCMA has been implicated in myeloma cell growth and survival, and is found in virtually all multiple myeloma cells.

When belantamab mafodotin binds to BCMA, the cancer-killing molecule is released into the cell and causes cell death. The technology used in the therapy is licensed from Seattle Genetics and BioWa.

The safety and efficacy of belantamab mafodotin are being assessed in the DREAMM clinical trial program, which comprises five ongoing clinical trials, with an additional six set to begin shortly.

One of these trials, DREAMM-2, is testing belantamab mafodotin in patients who have received at least three prior lines of therapy, have failed to respond to a proteasome inhibitor such as Velcade (bortezomib) and an immunomodulatory agent such as Revlimid (lenalidomide), and are relapsed or refractory to treatment with an anti-CD38 antibody such as Darzalex (daratumumab).

The trial has enrolled 196 patients, who were randomly assigned to receive one of two belantamab mafodotin doses — 2.5 mg/kg or 3.4 mg/kg — once every three weeks.

In addition to its primary goal of objective response rate, the trial will also measure outcomes including duration of response, time to disease progression or death, overall survival, safety, and a number of laboratory assessments.

The treatment was safe and well-tolerated, with profiles similar to that seen in the DREAMM-1 Phase 1 trial (NCT02064387), the first human trial testing belantamab mafodotin.

DREAMM-1 showed that 60% of relapsed or refractory myeloma patients responded to belantamab mafodotin — including 15% with complete responses — and they lived for a median of 12 months without any signs of disease worsening.

Based on these results, GSK said it will seek the approval of belantamab mafodotin for the treatment of relapsed and refractory multiple myeloma by the end of 2019.

“We are on track to file belantamab mafodotin later this year and continue to investigate how it could help even more patients with this disease,” Barron said.

In November 2017, belantamab mafodotin received breakthrough therapy status from the U.S. Food and Drug Administration and a PRIME designation by the European Medicines Agency. Both of these are meant to increase the speed and support the development of promising therapies.