British drugmaker GSK said that its Blenrep (belantamab mafodotin) has met the primary endpoint in the DREAMM-7 head-to-head Phase 3 trial of patients with relapsed/refractory multiple myeloma.

Blenrep is an antibody-drug conjugate. It is made up of a humanised B-cell maturation antigen monoclonal antibody conjugated to the cytotoxic agent auristatin F through a non-cleavable linker.

The late-stage trial assessed belantamab mafodotin as a second-line treatment for relapsed or refractory multiple myeloma.

According to the results from a planned interim efficacy analysis of the study, the drug achieved progression-free survival (PFS) which was the primary endpoint of the trial.

Blenrep, when combined with bortezomib plus dexamethasone (BorDex), extended the time to disease progression or death compared to daratumumab plus BorDex, which is the existing standard of care for this multiple myeloma.

In addition, the trial showed a strong and clinically meaningful overall survival (OS) trend with a nominal p value < 0.0005. The study was continued to follow up for OS.

The belantamab mafodotin regimen’s safety and tolerability matched the established safety profiles of the individual medicines.

GSK R&D oncology global head and senior vice president Hesham Abdullah said: “Patients with multiple myeloma need treatment options after first relapse that are efficacious, readily accessible and have novel mechanisms of action.

“We are particularly encouraged by the potential for belantamab mafodotin when combined with BorDex to address the high unmet need in relapsed/refractory multiple myeloma, given the head-to-head comparison with the daratumumab-based standard of care regimen.”

The DREAMM-7 Phase 3 trial is a multicentre, open-label, randomised study.

It randomised 494 participants at a 1:1 ratio to get either antibody-drug conjugate in combination with BorDex or a combination of daratumumab and BorDex.

Key secondary endpoints included OS, duration of response, and minimal residual disease negativity rate.

The British drug company is also conducting a head-to-head Phase 3 DREAMM-8 trial whose results are expected in the second half of 2024.