GSK Secures Japanese Approval for Blenrep Combinations in Relapsed/Refractory Multiple Myeloma Based on Robust Phase III Data
In a major advancement for the treatment landscape of multiple myeloma, GSK plc (LSE/NYSE: GSK) announced that Japan’s Ministry of Health, Labour and Welfare (MHLW) has granted regulatory approval for Blenrep (belantamab mafodotin) in combination regimens for adult patients with relapsed or refractory multiple myeloma. This decision marks a significant milestone for patients in Japan facing limited options after disease relapse and builds on the mounting clinical evidence supporting the efficacy of Blenrep-based therapies.
The MHLW’s approval specifically covers two novel combination regimens involving Blenrep: one with bortezomib plus dexamethasone (BVd) and another with pomalidomide plus dexamethasone (BPd). These approvals are based on the compelling clinical data from the DREAMM-7 and DREAMM-8 phase III studies, which demonstrated superior progression-free survival (PFS) and additional clinical benefits when compared to established standard-of-care regimens in patients who had received at least one prior therapy. The move follows the orphan drug designation granted earlier by the MHLW, underscoring the high unmet medical need for new therapeutic strategies in Japan’s multiple myeloma population.
A High-Need Therapeutic Area in Japan
Multiple myeloma remains a challenging blood cancer with a complex disease course. In Japan, approximately 43% of patients diagnosed with multiple myeloma are alive five years after their initial diagnosis. Most patients eventually experience relapse, necessitating effective treatment strategies that can extend survival and maintain quality of life.
GSK’s Blenrep—an antibody-drug conjugate (ADC) targeting B-cell maturation antigen (BCMA)—is the only anti-BCMA therapy currently approved in Japan for use in multiple myeloma. The approval of Blenrep combinations thus represents a critical development for patients requiring options beyond first-line treatment.
“Today’s approval brings the benefits of Blenrep combinations to patients with relapsed or refractory multiple myeloma in Japan,” said Dr. Hesham Abdullah, Senior Vice President and Global Head of Oncology R&D at GSK. “Patients need additional treatment options at or after first relapse that can extend remission and survival versus standard of care. Blenrep combinations have the potential to redefine treatment outcomes based on superior efficacy shown in two phase III trials, with the added advantage of in-office administration in both academic and community treatment settings.”
Clinical Evidence from DREAMM-7 and DREAMM-8 Trials
The MHLW’s decision is anchored in results from two pivotal global phase III studies: DREAMM-7 and DREAMM-8. These trials evaluated the effectiveness and safety of Blenrep in combination with two widely used backbone therapies in patients with relapsed or refractory multiple myeloma.
DREAMM-7 compared the Blenrep + bortezomib + dexamethasone (BVd) regimen to the standard daratumumab + bortezomib + dexamethasone (DVd) regimen. The study demonstrated that the Blenrep combination significantly improved progression-free survival and also showed a positive trend in overall survival (OS). These results were statistically significant and clinically meaningful, suggesting a notable advancement over current therapies.
DREAMM-8 investigated the combination of Blenrep + pomalidomide + dexamethasone (BPd) against the standard regimen of pomalidomide + bortezomib + dexamethasone (PVd). Once again, Blenrep demonstrated superior efficacy, with marked improvements in progression-free survival and depth of response.
Across both trials, the efficacy of Blenrep-based combinations extended to a broad patient population, including individuals with poor prognostic features, such as high-risk cytogenetics and lenalidomide-refractory disease—categories typically associated with worse outcomes.
Safety Profile and Management of Adverse Events
In terms of safety and tolerability, the Blenrep combination regimens demonstrated profiles consistent with what is known for each individual agent. While Blenrep has been associated with ocular toxicity—a known class effect of the drug—these side effects were manageable and did not lead to high discontinuation rates.
In both DREAMM-7 and DREAMM-8, ocular events such as changes in visual acuity and findings from eye exams were primarily managed through dose modifications and adjustments to the dosing schedule. By extending the time between infusions or reducing the dose, most patients were able to continue therapy without permanent vision damage. Importantly, 83% of ocular events were resolved, and no cases of permanent bilateral vision loss (defined as worse than 20/200 vision in both eyes) were reported in the trials or from previous post-marketing data on Blenrep monotherapy.
Aside from ocular side effects, other commonly reported adverse events in the combination arms included hematologic and gastrointestinal toxicities. In the DREAMM-7 trial, thrombocytopenia (87%) and diarrhea (32%) were most frequent. In DREAMM-8, neutropenia (63%), thrombocytopenia (55%), and COVID-19 (37%) were prominent. Despite these rates, adverse events were generally manageable with supportive care and dose adjustments.
A Convenient Option for Broader Patient Access
Beyond efficacy and safety, one of the major advantages of the Blenrep combination regimens is the convenience of administration. Unlike other therapies that may require complex preparation or hospitalization, Blenrep-based combinations can be administered in-office in both academic and community oncology settings. The drug does not require elaborate premedication protocols or inpatient monitoring, making it more accessible to a wider population of patients, including those treated outside of major urban centers.
This factor is particularly relevant in Japan, where access to cutting-edge oncology treatments can vary depending on geographic location and facility type. The ability to administer Blenrep without logistical complexity could increase its uptake across treatment settings and help more patients benefit from its therapeutic potential.
Building on Global Regulatory Momentum
Japan is now the second major global regulatory authority to approve Blenrep combination regimens for the treatment of relapsed or refractory multiple myeloma, following the United Kingdom’s Medicines and Healthcare products Regulatory Agency (MHRA), which granted the world’s first regulatory approval for these combinations just last month.
These back-to-back approvals are part of GSK’s broader strategy to solidify Blenrep’s position as a cornerstone therapy in the evolving treatment paradigm for multiple myeloma. With additional regulatory submissions likely underway or pending in other markets, the company is clearly building momentum to establish a global presence for its BCMA-targeted therapy.
Redefining Multiple Myeloma Treatment
The approval of Blenrep combination therapies in Japan not only reinforces the importance of innovative ADC-based treatments in multiple myeloma but also signals a shift toward earlier use of BCMA-targeted agents in the treatment continuum.
Until now, many BCMA-directed therapies—including CAR T-cell therapies and bispecific antibodies—have been reserved for later lines of treatment due to logistical challenges or limited access. With the success of Blenrep in phase III trials and its compatibility with widely used backbone agents like bortezomib and pomalidomide, clinicians now have an opportunity to introduce BCMA-targeted therapy earlier in the treatment journey.
As multiple myeloma continues to evolve into a chronic but relapsing disease, the need for treatment options that are not only effective but also practical and accessible becomes paramount. With the latest approval from Japan’s MHLW, GSK’s Blenrep combinations offer a compelling new option that aligns with these goals.
