Pembrolizumab looks good for treated, advanced MSI-H/dMMR endometrial cancer

Use of pembrolizumab helps maintain or improve health-related quality of life (HRQoL) in patients with previously treated, advanced endometrial cancer characterized by high levels of microsatellite instability (MSI) or deficient mismatch repair (MSI-H/dMMR), according to data from the phase II KEYNOTE-158 study.

The present analysis included KEYNOTE-158 patients from cohorts D (endometrial cancer with any MSI status) and K (any MSI-H/dMMR solid tumour except colorectal) who had previously treated, advanced MSI-H/dMMR endometrial cancer.

KEYNOTE-158 patients received pembrolizumab 200 mg once every 3 weeks for 35 cycles. They were asked to complete EORTC QLQ-C30 and EQ-5D-3L questionnaires at baseline, at regular intervals during treatment, and 30 days after treatment discontinuation.

Eighty-four out of the 90 enrolled patients completed ≥1 HRQoL questionnaire and were included in the analysis. QLQ-C30 and EQ-5D-3L compliance rates were 90 percent and 94 percent, respectively, at baseline, and 92 percent and 93 percent at week 9.

At week 9, the mean QLQ-C30 GHS/QoL scores improved by 6.08 (95 percent confidence interval [CI], 0.71–11.46) points from baseline in the overall population, with greater improvement noted in patients who achieved complete or partial response (11.67 [95 percent CI, 5.33–18.00]-point increase).

Likewise, mean EQ-5D-3L VAS scores improved by 6.00 (2.25–9.75) points in the overall population and by 9.11 (5.24–12.98) points in patients with complete or partial response.

The findings provide further support to the efficacy and safety results from KEYNOTE-158 and pembrolizumab use in this setting.