The Food and Drug Administration granted accelerated approval to dostarlimab-gxly for adult patients with mismatch repair deficient (dMMR) recurrent or advanced endometrial cancer, as determined by an FDA-approved test, that has progressed on or following a prior  platinum-containing regimen.

Efficacy was evaluated based on cohort (A1) in GARNET Trial, a multi-centre, multi-cohort, open-label trial in patients with advanced solid tumours.

The efficacy population consisted of 71 patients with dMMR recurrent or advanced endometrial cancer who progressed on or after  a platinum-containing regimen.

Patients received dostarlimab-gxly, 500 mg intravenously, every 3 weeks for 4 doses followed by 1,000 mg intravenously every 6 weeks.

The main efficacy endpoints were overall response rate (ORR) and duration of response (DOR), as assessed by blinded independent central review (BICR) according to RECIST 1.1. Confirmed ORR was 42.3% (95% CI: 30.6%, 54.6%). The complete response rate was 12.7% and partial response rate was 29.6%. Median DOR was not reached, with 93.3% of patients having  durations  ≥6 months (range: 2.6 to 22.4 months, ongoing at last assessment).

Serious adverse reactions occurred in 34% of patients receiving dostarlimab-gxly.

Serious adverse reactions in >2% of patients included sepsis , acute kidney injury , urinary tract infection , abdominal pain , and pyrexia .

The most common adverse reactions (≥20%) were fatigue/asthenia, nausea, diarrhoea, anaemia, and constipation.

The most common grade 3 or 4 adverse reactions (≥2%) were anaemia and transaminases increased. Immune-mediated adverse reactions can occur including pneumonitis, colitis, hepatitis, endocrinopathies, and nephritis.

The recommended dostarlimab-gxly dose and schedule (doses 1 through 4) is 500 mg every 3 weeks. Subsequent dosing, beginning 3 weeks after dose 4, is 1,000 mg every 6 weeks until disease progression or unacceptable toxicity.

Dostarlimab-gxly should be administered as an intravenous infusion over 30 minutes.

View full prescribing information for dostarlimab-gxly.

Source: FDA