Adding dostarlimab improves progression-free survival in endometrial cancer

For patients with primary advanced or recurrent endometrial cancer, dostarlimab plus carboplatin-paclitaxel increases progression-free survival versus carboplatin-paclitaxel alone, according to a study published online March 27 in the New England Journal of Medicine.

Mansoor R. Mirza, M.D., from Copenhagen University Hospital in Denmark, and colleagues conducted a phase 3, global trial involving patients with primary advanced stage III or IV or first recurrent endometrial cancer who were randomly assigned to receive dostarlimab (500 mg) or placebo plus carboplatin and paclitaxel every three weeks for six cycles, followed by dostarlimab (1,000 mg) or placebo every six weeks for up to three years. A total of 494 patients were randomly assigned in a 1:1 ratio; 23.9 percent had mismatch repair-deficient (dMMR), microsatellite instability-high (MSI-H) tumors.

The researchers found that in the dMMR-MSI-H population, estimated progression-free survival was 61.4 and 15.7 percent in the dostarlimab and placebo groups, respectively, at 24 months (hazard ratio for progression or death, 0.28). Progression-free survival at 24 months was 36.1 and 18.1 percent in the dostarlimab and placebo groups, respectively, in the overall population (hazard ratio, 0.64). Overall survival was 71.3 and 56.0 percent with dostarlimab and placebo, respectively, at 24 months (hazard ratio for death, 0.64). Severe and serious adverse events occurred more often in the dostarlimab group.

"The progression-free survival benefit in the dostarlimab group did not appear to be consistent across all prespecified subgroups," the authors write.

Several authors disclosed financial ties to pharmaceutical companies, including GSK, which manufactures dostarlimab and funded the study.