Phase III Success for GSK's Blenrep in Treating Multiple Myeloma

GlaxoSmithKline (GSK) has reported positive results from the Phase III DREAMM-7 trial, which indicates that its antibody-drug conjugate, Blenrep, combined with two other drugs, significantly enhances progression-free survival in patients suffering from multiple myeloma that has relapsed or become resistant to treatment. The open-label study, which was a direct comparison, pitted the Blenrep regimen against a combination therapy involving Johnson & Johnson's Darzalex. The data revealed that the Blenrep combination reduced the risk of disease progression or death by a notable 59%, a result that was statistically significant.

The median progression-free survival for patients on the Blenrep regimen was 36.6 months, which is nearly three times longer than the 13.4 months observed in the group treated with the alternative therapy. GSK plans to present these findings at an upcoming American Society of Clinical Oncology event.

The senior vice president and global head of Oncology R&D at GSK, Hesham Abdullah, stated that the DREAMM-7 trial results strengthen their confidence in Blenrep's potential to transform the treatment landscape for multiple myeloma after the first relapse. The company intends to share these findings with health regulatory authorities worldwide.

While the primary focus of DREAMM-7 was on progression-free survival, the study also aimed to evaluate the overall survival outcomes. The interim analysis indicated a substantial trend towards improved overall survival with the Blenrep regimen, reducing the risk of death by 43% compared to the Darzalex group. However, this effect has not yet met the statistical significance criteria, with a p-value of 0.00049, which is above the required threshold of 0.00037.

Safety concerns were also addressed, with the study noting several eye-related side effects associated with Blenrep treatment. A significant proportion of patients, 34%, experienced grade 3 or higher ocular adverse events, which were largely reversible and manageable with dosage adjustments. However, these side effects led to 9% of patients discontinuing treatment.

The positive outcomes from the DREAMM-7 trial could pave the way for Blenrep's re-entry into the U.S. market. The drug had previously received accelerated approval from the FDA in August 2020 for treating relapsed or refractory multiple myeloma in adults. However, following a failed confirmatory Phase III DREAMM-3 study in November 2022, the FDA requested its withdrawal from the market. The latest results may signal a potential return for Blenrep, pending further regulatory review and approval.