SHERIDAN, WYOMING – July 25, 2025 – The U.S. Food and Drug Administration has delayed its decision on GSK’s antibody-drug conjugate Blenrep, postponing the company's market reentry plans for the treatment of relapsed or refractory multiple myeloma. The updated Prescription Drug User Fee Act (PDUFA) target date is now set for October 23, 2025, following the agency's request for additional information.
Originally granted accelerated approval in 2020, Blenrep was withdrawn in 2022 after failing its confirmatory Phase III DREAMM-3 trial. GSK has since mounted a data-driven effort to revive the therapy’s prospects, presenting positive results from subsequent clinical studies. However, the FDA’s decision to extend the review process underscores lingering regulatory hesitation around the drug’s safety and clinical profile.
Regulatory pause reflects unresolved risk-benefit concerns
According to GSK, the FDA required more time to assess newly submitted data tied to the Biologics License Application (BLA). “The FDA needs more time to ‘review additional information provided in support of the application,’” the company stated in its announcement.
This delay follows an earlier advisory panel meeting in which the Oncologic Drugs Advisory Committee raised critical safety and efficacy concerns. Specifically, internal FDA reviewers highlighted “the high rates of ocular toxicity and dose modifications” observed in the DREAMM-7 and DREAMM-8 trials. The agency concluded that “the benefit-risk profile of [Blenrep] for the proposed indications . . . remains unclear.”
Clinical trial results show promise, but panel votes signal headwinds
GSK has built its case for Blenrep’s return on two late-stage studies. In February 2024, data from the Phase III DREAMM-7 trial showed that combining Blenrep with bortezomib and dexamethasone reduced the risk of disease progression or death by 59% compared to a Darzalex-based regimen. Additional data from DREAMM-8, presented in June, demonstrated Blenrep’s superiority over Takeda’s Velcade in patients previously treated with at least one therapy line.
Despite these results, the FDA panel remained unconvinced:
- The advisory committee voted 7–1 against approving Blenrep in combination with pomalidomide and dexamethasone.
- A second vote ended 5–3 against Blenrep paired with bortezomib and dexamethasone.
These outcomes signal strong reservations from independent experts regarding the drug’s risk management, especially around ocular adverse events.
Demographic representation flagged as a further issue
In addition to safety concerns, the FDA briefing document cited the limited demographic diversity in GSK’s pivotal trials. It noted “limited enrollment in the U.S., and limited enrollment of Black or African American patients and those 75 years of age and older,” raising questions about the generalizability of the study outcomes to the broader U.S. population.
Strategic implications for GSK’s oncology pipeline
The delay represents a setback for GSK’s oncology ambitions. A successful relaunch of Blenrep as a second-line therapy could have supported a strong commercial rebound and contributed to portfolio diversification amid increasing competition in the hematologic cancer segment. The company had previously described Blenrep as having “multi-blockbuster” potential.
GSK must now navigate regulatory scrutiny, expert skepticism, and public safety concerns while aiming to satisfy FDA requirements. The updated action date in October will be a key milestone for both GSK’s clinical development team and the broader oncology investment community.
Learn more at www.gsk.com.