On February 9, 2023, the FDA approved dostarlimab-gxly (Jemperli; GlaxoSmithKline) for the treatment of adult patients with mismatch repair-deficient (dMMR), recurrent or advanced endometrial cancer, as determined by an FDA-approved test, whose disease has progressed on or following a previous platinum-containing regimen in any setting and who are not candidates for curative surgery or radiation.
In April 2021, dostarlimab received accelerated approval for adult patients with dMMR, recurrent or advanced endometrial cancer, as determined by an FDA-approved test, whose disease has progressed on or following a previous platinum-containing regimen.
The FDA based the regular approval on additional data collected from the A1 expansion cohort of the ongoing GARNET study, a phase 1, multicenter, open-label, single-arm clinical trial of dostarlimab monotherapy in patients with advanced or recurrent solid tumors. Cohort A1 evaluated the efficacy of dostarlimab in 141 patients with dMMR, recurrent or advanced endometrial cancer whose disease has progressed on or after a platinum-containing regimen.
The major efficacy outcome measures were overall response rate (ORR) and duration of response (DOR) as determined by blinded independent central review per RECIST version 1.1. The confirmed ORR was 45.4% (95% confidence interval, 37.0-54.0), with a 15.6% complete response rate and a 29.8% partial response rate. Median DOR had not been reached; however, 85.9% of patients had responses that lasted ≥12 months and 54.7% of patients had responses that lasted ≥24 months.
The most common (≥20%) adverse reactions were fatigue/asthenia, anemia, rash, nausea, diarrhea, constipation, and vomiting. The most common (≥2%) grade 3 or 4 adverse reactions were anemia, increased transaminases, urinary tract infection, fatigue/asthenia, and diarrhea.
