GSK’s Blenrep Combination Therapies Gain UK Approval: A New Era in Multiple Myeloma Treatment

The UK’s Medicines and Healthcare products Regulatory Agency (MHRA) has approved GSK’s Blenrep (belantamab mafodotin) in combination therapies for relapsed or refractory multiple myeloma (RRMM), marking a pivotal milestone in the treatment of this aggressive blood cancer. This first global regulatory green light for Blenrep in combination regimens positions it as a transformative option for patients who have exhausted prior therapies. With robust clinical trial data demonstrating extended survival and superior efficacy compared to existing standards, Blenrep’s resurgence—from a near退市 in 2022 to a £3 billion sales target—underscores its potential to redefine the RRMM treatment paradigm.

Clinical Breakthroughs: Efficacy and Survival Gains

The approval hinges on results from two phase 3 trials, DREAMM-7 and DREAMM-8, which demonstrated statistically significant improvements in progression-free survival (PFS) and overall survival (OS).

In DREAMM-7, Blenrep combined with bortezomib/dexamethasone achieved a median PFS of 36.6 months, nearly tripling the 13.4 months seen with daratumumab-based therapy. Blenrep reduced the risk of progression or death by 59% and cut mortality risk by 42%, with 83% of patients achieving a partial response or better—a stark contrast to 71% for the comparator. Similarly, DREAMM-8 showed a 48% risk reduction in progression or death for Blenrep plus pomalidomide/dexamethasone versus bortezomib-based therapy, with 77% of patients achieving meaningful responses.

These results are particularly compelling given the poor prognosis of RRMM patients, where only 55% survive five years post-diagnosis in the UK. Dr. Joseph Mikhael of the International Myeloma Foundation noted Blenrep’s BCMA-targeting mechanism as a critical advance, offering a durable remission option for those failing earlier therapies.

Safety Profile: Trade-Offs and Manageability

While Blenrep’s efficacy is undeniable, its safety profile requires careful consideration. In DREAMM-7, 95% of patients on Blenrep experienced grade 3–4 adverse events (AEs), primarily neutropenia and thrombocytopenia, compared to 78% on daratumumab. Ocular events, such as blurred vision, occurred in 89% of Blenrep patients in DREAMM-8, though most were reversible.

Despite these risks, the manageable nature of these AEs—coupled with Blenrep’s survival benefits—suggests it could become a preferred option for clinicians.

Market Dynamics: A Competitive Advantage Over CAR-T Therapies

Blenrep’s off-the-shelf ADC design offers a distinct edge over competing therapies like J&J’s Carvykti, a CAR-T cell therapy requiring complex manufacturing and prolonged hospitalization. While Carvykti boasts high response rates, its logistical and cost barriers limit accessibility. By contrast, Blenrep’s ready-to-administer profile and superior OS data position it as a pragmatic alternative for widespread use.

GSK’s shares rose 4.2% in early trading following the approval, reflecting investor optimism. However, sustained gains will hinge on FDA approval by July 2025, a critical milestone for accessing the lucrative U.S. market, which accounts for nearly half of global multiple myeloma drug sales.

Commercial Ambitions: £3 Billion Target and Beyond

GSK aims for Blenrep to generate £3 billion in annual sales by 2031, contributing to a revised £40 billion sales target for the company. With applications pending in 14 additional markets, including the U.S., and a strong evidence base for earlier-line use, Blenrep’s pipeline expansion could amplify its commercial potential.

Risks and Considerations

While Blenrep’s clinical profile is compelling, challenges remain. The drug’s ocular toxicity and myelosuppression risks may limit its use in frail patients, and competition from emerging therapies—such as GSK’s own anti-BCMA bispecific antibody—is looming. Additionally, the FDA’s decision will be pivotal; a rejection could delay U.S. market entry by years.

Conclusion: A Strategic Investment in Oncology Innovation

The UK approval of Blenrep’s combinations represents a turning point for GSK’s oncology portfolio and a new standard in RRMM care. With 36.6-month median PFS and 42% OS improvement in pivotal trials, Blenrep offers a survival advantage unmatched by existing therapies. Its BCMA-targeted mechanism and off-the-shelf convenience address critical gaps in treatment accessibility, positioning it to capture significant market share.

Investors should closely watch the July 2025 FDA decision, which could unlock a £3 billion revenue stream. Even with execution risks, Blenrep’s resurgence—from near-退市 to global approval—demonstrates GSK’s R&D resilience. In a landscape where only 55% of RRMM patients survive five years, Blenrep’s ability to extend survival and improve response rates makes it a compelling play on oncology innovation. For investors, this is more than a drug approval—it’s a glimpse into the future of targeted cancer therapies.

While J&J’s Carvykti dominates headlines, GSK’s Blenrep offers a scalable, clinic-ready alternative. With the UK leading the way, the stage is set for Blenrep to deliver on its £3 billion promise—and for GSK to reclaim its place as an oncology leader.