Dostarlimab for the treatment of advanced endometrial cancer.

INTRODUCTION: Between 20% and 30% of the endometrial cancers (EC) are associated with a deficiency of a mismatch repair (MMRd) protein or high microsatellite instability (MSI-H), characteristics that render the tumor more sensitive to immune checkpoint inhibitors. There is no standard treatment for advanced EC after progression to a platinum-containing regimen. AREAS COVERED: The phase I GARNET clinical trial assessed the safety, tolerability, and antitumor activity of anti-PD1 dostarlimab in patients with advanced solid tumors. The A1 cohort of this trial enrolled patients with MMRd or MSI-H recurrent or advanced EC who had previously received a platinum-containing regimen. The results of this cohort showed significant clinical activity, durable responses, and a favorable safety profile, without reducing quality of life. Based on these data, dostarlimab achieved accelerated approval. EXPERT OPINION: Although a randomized study has not yet been conducted, dostarlimab monotherapy should be the treatment of choice for patients with advanced MMRd EC in progression after a platinum-containing regimen. Selecting patients with EC for immune checkpoint inhibitors using the MMRd predictive biomarker could facilitate more efficient and sustainable health systems and avoid the use of more toxic combinations, leading to personalized medicine.