An updated analysis of the GlaxoSmithKline's GARNET trial has shown that dostarlimab provided “clinically meaningful” results in some women with endometrial cancer.

The trial is assessing the safety and effectiveness of the anti-programmed death-1 (PD-1) monoclonal antibody in women with recurrent or advanced mismatch repair-deficient (dMMR) endometrial cancer who progressed on or after a platinum-based regimen.

This updated analysis included patients with dMMR endometrial cancer who had measurable disease at baseline and ≥6 months of follow-up by the data cutoff.

Patients were given 500mg of dostarlimab once every three weeks for four doses, followed by 1,000mg once every six weeks until disease progression.

The primary endpoints were confirmed objective response rate (ORR) and duration of response (DoR).

According to the data, treatment with dostarlimab showed an ORR of 42% and a disease control rate of 58%. Overall, 13% of patients had a complete response and 30% of patients had a partial response. At the time of data cutoff, with a median follow up of 11.2 months, the median DOR had not been reached.

On the safety side, dostarlimab was well tolerated with a low discontinuation rate (2%) due to treatment-related adverse events, the most common of which were asthenia (15%), diarrhoea (15%), fatigue (14%), and nausea (13%).

Commenting on the results, Dr Ana Oaknin, head of the Gynaecologic Cancer Program at Vall d’Hebron Institute of Oncology, Barcelona, and primary investigator for GARNET, said: “There are limited treatment options for women with advanced or recurrent endometrial cancer, and prognosis of these patients is poor. The results observed in the GARNET trial indicate the potential of dostarlimab to offer a new treatment option for women with this challenging disease.”

Dostarlimab is not currently approved for use anywhere in the world.