GSK Blenrep combos win approval in Japan for multiple myeloma

Superior efficacy results from the pivotal DREAMM-7 and DREAMM-8 phase III trials in relapsed or refractory multiple myeloma support MHLW approval of Blenrep combinations. These include statistically significant and clinically meaningful progression-free survival (PFS) results for Blenrep combinations versus standards of care in both trials and overall survival (OS) in DREAMM-7. The safety and tolerability profiles of the Blenrep combinations were broadly consistent with the known profiles of the individual agents.

Hesham Abdullah, Senior Vice President, Global Head Oncology, R&D, GSK, said, “The approval brings the benefits of Blenrep combinations to patients with relapsed or refractory multiple myeloma in Japan. 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.”

Most patients with multiple myeloma experience relapse, and in Japan only about 43% remain alive five years after diagnosis. Blenrep is a anti-BCMA (B-cell maturation antigen) antibody-drug conjugate (ADC) approved in multiple myeloma, providing patients at or after relapse with a differentiated mechanism of action. Blenrep combinations can be administered to a range of patient types in any oncology treatment setting without complex pre-administration regimens or hospitalisation.

In the DREAMM-7 and DREAMM-8 clinical trials, Blenrep combinations consistently benefited a broad range of patients, including those with poor prognostic features or outcomes, such as high-risk cytogenetics or those refractory to lenalidomide. Both trials also showed clinically meaningful improvements across all other secondary efficacy endpoints, including deeper and more durable responses versus the respective comparators.

Eye-related side effects associated with Blenrep were successfully managed by extending time between infusions and through dose reductions, allowing patients to maintain benefit and resulting in low rates of discontinuation (≤9%) in both trials. Eye exam findings and changes in visual clarity (known as visual acuity) resolved in 83% of occurrences; with the trials ongoing, the remaining occurrences were in patients with follow-up ongoing or lost to follow-up. There have been no confirmed cases of permanent bilateral vision loss (i.e., no permanent bilateral eye exam findings of 20/200 or worse) based on current Blenrep clinical trial data and previous monotherapy post-marketing use.

This is the second major regulatory approval for Blenrep combinations for the treatment of relapsed or refractory multiple myeloma, following the first authorisation in the world last month by the UK Medicines and Healthcare products Regulatory Agency (MHRA).

Blenrep combinations are currently under review in all major markets globally, including in the US with a Prescription Drug User Fee Act (PDUFA) date of 23 July 2025, European Union, China, (based on the results of DREAMM-7, with Breakthrough Therapy Designation for the combination and priority review for the application), Canada, and Switzerland (with priority review for DREAMM-8).

Multiple myeloma is the third most common blood cancer globally and is generally considered treatable but not curable. There are approximately more than 180,000 new cases of multiple myeloma diagnosed globally each year, including more than 7,200 in Japan. Research into new therapies is needed as multiple myeloma commonly becomes refractory to available treatments. Many patients with multiple myeloma are treated in a community cancer setting, leaving an urgent need for new, effective therapies with manageable side effects that can be administered outside of an academic centre.

Blenrep is an ADC comprising a humanised BCMA monoclonal antibody conjugated to the cytotoxic agent auristatin F via a non-cleavable linker. The drug linker technology is licensed from Seagen Inc.; the monoclonal antibody is produced using POTELLIGENT Technology licensed from BioWa Inc., a member of the Kyowa Kirin Group.

In April 2025, the UK Medicines and Healthcare products Regulatory Agency (MHRA) licensed Blenrep combinations for the treatment of relapsed or refractory multiple myeloma in adult patients who have received at least one prior therapy.