Pembrolizumab may offer improved health-related quality of life (HRQOL) compared with chemotherapy in patients with previously untreated microsatellite instability-high or mismatch repair-deficient metastatic colorectal cancer (CRC), according to an analysis of phase 3 data published in The Lancet Oncology

The KEYNOTE-177 trial ( Identifier: NCT02563002) included 307 patients with microsatellite instability-high or mismatch repair-deficient metastatic CRC.

The patients were randomly assigned to receive frontline pembrolizumab monotherapy or chemotherapy. Previous results showed superior progression-free survival for the patients who received pembrolizumab.

Continue Reading

The HRQOL analysis included 294 of the patients enrolled —152 who received pembrolizumab and 142 who received chemotherapy.

Three validated HRQOL questionnaires were used at baseline and various timepoints: the EuroQoL 5 Dimensions 3 Levels (EQ-5D-3L), the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30), and the EORTC Quality of Life Questionnaire-Colorectal 29 (QLQ-CR29).

From baseline to week 18, EORTC QLQ-C30 global health status/quality of life scores improved in the pembrolizumab arm but worsened in the chemotherapy arm. The  between-arm least squares mean difference was 8.96 (95% CI, 4.24-13.69; P =.0002).

In general, patients in the pembrolizumab arm had stable or improved scores from baseline to week 18 for most of the functional and symptom scales assessed by the EORTC QLQ-C30 and EORTC QLQ-CR29 questionnaires. In contrast, patients in the chemotherapy arm typically had worsening scores from baseline to week 18.

The most considerable differences between the treatment arms were seen for the following categories, and all favored pembrolizumab: physical functioning, role functioning, social functioning, fatigue, pain, appetite loss and body image, sexual interest (men), abdominal pain, buttock pain, bloating, dry mouth, hair loss, taste, and sore skin among patients with a stoma.

“These data, along with the previously reported clinical benefits, support pembrolizumab as a first-line treatment option for this population,” the study authors concluded.

Disclosure: This research was supported by Merck Sharp & Dohme. Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.


Andre T, Amonkar M, Norquist JM, et al. Health-related quality of life in patients with microsatellite instability-high or mismatch repair deficient metastatic colorectal cancer treated with first-line pembrolizumab versus chemotherapy (KEYNOTE-177): an open-label, randomised, phase 3 trial. Lancet Oncol. 2021;22(5):665-677. doi:10.1016/S1470-2045(21)00064-4