NEW YORK – GlaxoSmithKline on Tuesday said the US Food and Drug Administration has accepted its supplemental biologics license application seeking approval for the PD-1-targeted monoclonal antibody Jemperli (dostarlimab) with chemotherapy for treating adults with mismatch repair deficient (dMMR) and microsatellite instability-high (MSI-H) recurrent or advanced endometrial cancer.
The agency has granted the sBLA priority review. In its application, GSK submitted an interim analysis from the first part of the Phase III RUBY trial, in which investigators found that Jemperli-chemo statistically significantly and clinically meaningfully improved progression-free survival at two years among patients with dMMR/MSI-H endometrial cancer and in the overall treatment population compared with chemotherapy alone. The RUBY investigators published the study results in March in the New England Journal of Medicine.
In the dMMR/MSI-H subgroup, progression-free survival at two years was 61.4 percent for those who received Jemperli-chemo, compared with 15.7 percent for those on just chemo. In patients with mismatch repair proficient, microsatellite stable (MMRp/MSS) disease, the two-year progression-free survival rate was 28.4 percent on Jemperli-chemo and 18.8 percent on chemo. The overall survival rate also favored patients with dMMR/MSI-H cancers treated with Jemperli, with 83.3 percent of patients remaining alive after 24 months, compared with 58.7 percent in the chemo arm, and 67.7 percent for MMRp/MSS patients who received Jemperli and chemo.
An estimated 20 percent to 29 percent of endometrial cancers are dMMR/MSI-H.
With priority review, the FDA is slated to make a decision on GSK's application by Sept. 23. The application is being reviewed simultaneously by health authorities in Australia, Canada, Singapore, Switzerland, and the United Kingdom under the FDA Oncology Center of Excellence's Project Orbis.