NEW YORK – GlaxoSmithKline said on Friday that the European Commission granted conditional approval to its ant-PD1 antibody dostarlimab (Jemperli) to treat patients with mismatch repair-deficient (dMMR) or microsatellite instability-high (MSI-H) recurrent or advanced endometrial cancer that has progressed after platinum-based chemotherapy.
The European Medicines Agency approval was based on results from the Phase I GARNET trial. That study included 108 patients with dMMR/MSI-H endometrial cancer who progressed on or after a platinum-based chemotherapy. Among patients in that cohort, the objective response rate was 43.5 percent and the disease control rate was 55.6 percent.
The duration of response was not reached in the study, and the probability of maintaining a response at six months and 12 months was 97.9 percent and 90.9 percent, respectively.
"As we saw in the pivotal GARNET trial that supported this approval, treatment with dostarlimab has the potential to provide clinically significant and durable responses in patients who formerly had few treatment options," Ana Oaknin, primary investigator for the GARNET trial, said in a statement. "This approval represents a step forward, providing a new treatment for women with recurrent or advanced dMMR/MSI-H endometrial cancer who have previously failed a platinum-based chemotherapy."
This week, dostarlimab was also approved by the US Food and Drug Administration to treat patients with dMMR recurrent or advanced endometrial cancer that progressed after a platinum-based chemotherapy. That approval, however, did not include patients with MSH-H endometrial cancer.
The GARNET trial is studying dostarlimab as a monotherapy in four other expansion cohorts including mismatch repair proficient or microsatellite stable endometrial cancer, non-small cell lung cancer, dMMR or MSI-H non-endometrial tumors or POLE-mutated solid tumors, and platinum-resistant ovarian cancer without BRCA mutations.
GSK is also evaluating dostarlimab in combination with carboplatin-paclitaxel in an all-comer advanced or recurrent endometrial cancer population in the Phase III RUBY trial. The company also has a Phase II studying evaluating the combination of dostarlimab and its PARP inhibitor niraparib (Zejula) in patients with advanced or relapsed ovarian cancer who don't have a BRCA1/2 mutation.