GSK Presents New Data from the GARNET Study Demonstrating Potential of Dostarlimab to Treat a Subset of Women with Recurrent or Advanced Endometrial Cancer

GSK Presents New Data from the GARNET Study Demonstrating Potential of Dostarlimab to Treat a Subset of Women with Recurrent or Advanced Endometrial Cancer
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  • Data accepted as a late-breaking abstract and presented as a webinar as part of the Society of Gynecologic Oncology 2020 virtual congress
  • Patients in the updated analysis of GARNET include women with recurrent or advanced endometrial cancer who have progressed on or after platinum-based chemotherapy

PHILADELPHIA: GlaxoSmithKline plc has announced data from an updated analysis of the GARNET trial, which demonstrated that dostarlimab, an investigational anti-programmed death-1 (PD-1) monoclonal antibody, provided clinically meaningful results 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 (n=71). Patients received 500 mg of dostarlimab once every three weeks for four doses, followed by 1,000 mg once every six weeks until disease progression. The primary endpoints were confirmed objective response rate (ORR) and duration of response (DOR), as assessed against RECIST v 1.1 by blinded independent central review. GARNET is the largest dataset evaluating an anti-PD-1 in endometrial cancer.

Treatment with dostarlimab showed an ORR of 42% (95% CI; 31-55) and a disease control rate of 58% (95% CI; 45-69). 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 (1.87+ to 19.61+ months).

Dr. Axel Hoos, Senior Vice President and Head Oncology R&D, GSK said: “We are committed to developing medicines for patients who face high unmet medical need. We believe in the clinical potential of dostarlimab for women with advanced or recurrent dMMR endometrial cancer who urgently need additional treatment options for this incurable disease.”

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.”

The safety population included all patients with dMMR endometrial cancer who received at least one dose of dostarlimab (n=104). Results showed that dostarlimab was well tolerated with a low discontinuation rate (2%) due to treatment-related adverse events (TRAEs), consistent with the safety profiles of other anti-PD-1 therapies. The most commonly reported TRAEs were asthenia (15%), diarrhea (15%), fatigue (14%), and nausea (13%). No deaths associated with dostarlimab were reported in the study.

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