Belantamab Mafodotin Combos for Relapsed or Refractory Multiple Myeloma Approved for the First Time

The United Kingdom’s Medicines and Healthcare products Regulatory Agency (MHRA) has approved the use of B-cell maturation antigen (BCMA)-targeting antibody-drug conjugate (ADC) belantamab mafodotin in combination with bortezomib plus dexamethasone to manage relapsed or refractory multiple myeloma (MM) for adults with at least one prior treatment. The Agency also approved combination of this conjugate with pomalidomide plus dexamethasone for the same indication in lenalidomide-exposed adults with at least one prior therapy. These are the first-ever regulatory approvals granted to this conjugate for use in this disease.

GlaxoSmithKline (GSK) is developing and marketing belantamab mafodotin as Blenrep and announced the new approvals in a press release. This conjugate includes a humanized monoclonal antibody generated using the POTELLIGENT Technology licensed from BioWa Inc. of the Kyowa Kirin Group and applies drug linker technology licensed from Seagen Inc.

In the release, GSK company senior vice president and global head of oncology research and development Hesham Abdullah, MD, MSc, commented that, “[a]s the only BCMA-targeted ADC therapy, Blenrep has the potential, supported by robust phase III data, to extend survival and remission versus standard-of-care and redefine treatment at or after first relapse.”¹

The recent approvals from the MHRA were based specifically on favorable phase III data from DREAMM-7 and DREAMM-8; two multicenter, open-label, randomized clinical trials which each compared a belantamab-mafodotin-featuring combination against a standard-of-care triplet in patients with relapsed or refractory MM.

In DREAMM-7, belantamab mafodotin combined with bortezomib and dexamethasone was evaluated against daratumumab plus bortezomib and dexamethasone triplet in 494 patients with MM refractory to at least one line of therapy. Over a median follow-up of 28.2 months, patients on the test combination had more grade 3 or worse severity adverse events than patients on the standard-of-care triplet at 95% versus 78%, respectively. However, the test combination produced superior median progression-free survival (PFS) of 36.6 months versus 13.4 months, respectively, and overall survival (OS) at 18 months of 84% versus 73%, respectively.² Median OS had not been reached in either study arm at the time of the first interim analysis, but there was an evident trend in favor of the test combination with a hazard ratio of 0.57.³

In DREAMM-8, belantamab mafodotin combined with pomalidomide and dexamethasone was evaluated against pomalidomide plus bortezomib and dexamethasone triplet in 302 patients with MM refractory to at least one line of therapy, including lenalidomide. Over a median follow-up of 21.8 months, patients on the test combination had more grade 3 or worse severity adverse events than patients on the standard-of-care triplet, at 94% versus 76% respectively, and OS data were immature. However, the 12-month estimated PFS was 71% with the test combination versus 51% with the standard-of-care triplet.⁴

In the United States, GSK previously submitted to the FDA a Biologics License Application (BLA) for the use of these two belantamab-mafodotin combinations in relapsed or refractory MM, and the basis for this BLA was the DREAMM-7 and DREAMM-8 data.⁵ The FDA accepted and is currently reviewing this BLA, with a Prescription Drug User Fee Act action date set for July 23, 2025.^{1, 5}

Belantamab mafodotin combinations for relapsed or refractory MM are also currently under regulatory review in Canada, China, the European Union, Japan, and Switzerland.¹

The DREAMM-7 and DREAMM-8 trials were funded by GlaxoSmithKline.

References

1. Accessed May 2, 2025. https://www.gsk.com/en-gb/media/press-releases/blenrep-belantamab-mafodotin-combinations-approved-by-uk-mhra-in-relapsedrefractory-multiple-myeloma/
2. Hungria V, et al. N Engl J Med. 2024;391(5):393-407. doi:10.1056/NEJMoa2405090
3. Hungria V, et al. Blood 2024; 144 (Supplement 1): 772. doi:10.1182/blood-2024-200336
4. Dimopoulos MA, et al. N Engl J Med. 2024;391(5):408-421. doi:10.1056/NEJMoa2403407
5. Accessed May 2, 2025. https://www.gsk.com/en-gb/media/press-releases/blenrep-combinations-accepted-for-review-by-the-us-fda-for-the-treatment-of-relapsedrefractory-multiple-myeloma/