GSK has secured approval from the UK's medicines regulatory body to reintroduce its blood cancer therapy Blenrep (belantamab mafodotin) to the market, marking a significant comeback for the once-withdrawn treatment. The approval, announced on Thursday, specifically covers Blenrep in combination with other drugs for treating multiple myeloma in patients who experienced treatment failure or severe side effects with initial therapies.
This regulatory decision follows promising results from late-stage clinical trials demonstrating superior progression-free survival compared to current standards of care. The approval represents a critical step in GSK's strategy to expand its oncology portfolio and revitalize a drug once considered a potential blockbuster.
The Fall and Rise of Blenrep
Blenrep, an antibody-drug conjugate (ADC) targeting B-cell maturation antigen (BCMA), initially received approval in the US, UK, Europe, and other markets in 2020 as a monotherapy for later-line multiple myeloma treatment. However, in 2022, US regulators requested GSK withdraw the drug from all markets after the DREAMM-3 confirmatory trial revealed it failed to outperform existing treatments when used alone.
The drug's revival began with the DREAMM-7 study, which evaluated Blenrep in combination with Velcade (bortezomib) plus dexamethasone (BorDex) as a second-line therapy. This trial demonstrated superior efficacy compared to a regimen containing Darzalex (daratumumab), Takeda's Velcade, and dexamethasone – a current standard of care.
"Patients with multiple myeloma need treatment options after first relapse that are efficacious, readily accessible and have novel mechanisms of action," said Hesham Abdullah, global head of oncology R&D at GSK. "We are particularly encouraged by the potential for belantamab mafodotin when combined with BorDex to address high unmet need in relapsed/refractory multiple myeloma, given the head-to-head comparison with the daratumumab-based standard of care regimen."
Clinical Evidence Supporting Approval
The DREAMM-7 study results were compelling enough for the independent data monitoring committee to recommend unblinding the trial. The data showed Blenrep extended both the time to disease progression or death and overall survival compared to the Darzalex regimen.
These positive findings stand in stark contrast to the earlier DREAMM-3 study, which failed to show improvements in progression-free survival or overall survival when Blenrep was used as a third-line or later treatment.
Market Position and Competition
Blenrep was the first BCMA-targeting drug to reach the market, but the landscape has since evolved with several competitors emerging. These include CAR-T therapies like Bristol-Myers Squibb/bluebird bio's Abecma (idecabtagene vicleucel) and Johnson & Johnson/Legend Biotech's Carvykti (ciltacabtagene autoleucel), as well as bispecific antibodies such as J&J's Tecvayli (teclistamab) and Pfizer's Elrexfio (elranatamb).
However, these competing therapies are currently approved only for later-line treatment, potentially giving GSK an opportunity to position Blenrep earlier in the treatment pathway if the full DREAMM-7 dataset leads to additional regulatory approvals.
Global Expansion Plans
GSK expects further approvals for Blenrep combination therapy throughout the year. The company confirmed that Blenrep combinations are currently under regulatory review in 14 countries, signaling a potential global comeback for the drug.
Prior to its withdrawal, GSK had projected Blenrep could eventually generate annual sales of £3 billion ($3.8 billion), assuming it progressively moved into earlier lines of therapy. While the drug continued to generate modest sales of approximately £30 million ($38 million) in the first nine months of 2023 in markets where it remained available, this new approval pathway could revitalize its commercial prospects.
Implications for Multiple Myeloma Patients
Multiple myeloma, a cancer of plasma cells in the bone marrow, remains an incurable disease with a significant need for effective treatment options, particularly after initial therapy fails. The approval of Blenrep in combination therapy provides an important new option for these patients.
The combination approach appears to address the efficacy limitations seen when Blenrep was used as monotherapy, while potentially offering advantages over existing treatment regimens. GSK has indicated it will share the complete dataset from DREAMM-7 with health authorities worldwide to support additional regulatory submissions.
