Patient-reported outcome evaluations were becoming more popular to learn about potential new drugs from the patient’s point of view. However, patient-reported outcome assessments for anti-programmed death 1 (anti-PD-1) therapy in endometrial cancer still needed sufficient evidence. For a study, researchers sought to provide patient-reported outcome data from endometrial cancer patients treated with the anti-PD-1 monoclonal antibody dostarlimab in an expansion cohort of the GARNET study who had mismatch repair-deficient/microsatellite instability-high advanced or recurrent disease.

GARNET is a phase I single-arm trial of dostarlimab monotherapy in various tumor types. For 4 rounds of treatment, patients with advanced or recurrent mismatch repair-deficient/microsatellite instability-high endometrial cancer received 500 mg of intravenous dostarlimab, followed by 1000 mg every 6 weeks. The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30 was used to assess patient-reported outcomes as an exploratory endpoint (EORTC QLQ-C30).

The investigation comprised 88 individuals with mismatch repair-deficient endometrial cancer as of the data cutoff. Throughout cycle 7 of the experiment, there were no individual domains with a completion rate of less than 90.9% for the patient-reported outcome evaluation of more than 95.5%. When compared to the baseline, quality of life, emotional functioning, and social functioning all improved. From the beginning of cycle 7, all symptom ratings either increased or remained stable. For most patients, categorical change in response across all symptom measures and single-item response scores indicated stability or improvement. Less or around 2.5% experienced a 3-category worsening, and less or about 7.4% of patients experienced a 2-category worsening.

While taking dostarlimab for the treatment of recurrent or advanced mismatch repair-deficient endometrial cancer, the majority of patients remained stable or had an improvement in quality of life.