Health-related quality of life (HRQOL) in patients with metastatic non-squamous non-small-cell lung cancer without sensitising EGFR mutations or ALK translocations is maintained or marginally improved with the addition of pembrolizumab to standard chemotherapy.

Patient reported outcomes in the international KEYNOTE-189 study of more than 600 patients, found HRQOL was maintained from baseline to week 21 with pembrolizumab plus pemetrexed–platinum, whereas HRQOL declined with placebo plus pemetrexed–platinum.

There was no significant difference between the groups observed earlier at 12 weeks. 

Median time to deterioration in symptoms such as cough, chest pain, or dyspnoea was not reached in the pembrolizumab plus chemotherapy group compared to 7·0 months in the control group.

However deterioration in the composite of these symptoms was similar in both groups – 32% of patients in the pembrolizumab plus pemetrexed–platinum group and 33% of patients in the placebo plus pemetrexed–platinum group.

The study authors said the disease-related symptoms of cough, pain, and dyspnoea have been reported to have a substantial negative effect on lung cancer-specific QOL and to significantly interact with changes in ECOG performance status.

“Thus, our finding that time to deterioration in these symptoms might be longer with pembrolizumab plus pemetrexed–platinum provides further support for a clinically meaningful HRQOL benefit with this combination treatment regimen,” they wrote.

A Comment article in The Lancet Oncology said similar non-significant improvements have been seen in global health scores on other studies of pembrolizumab with chemotherapy. 

The KEYNOTE-189 study has previously published primary outcomes showing the addition of pembrolizumab to standard chemotherapy improved overall survival and progression-free survival compared to chemotherapy alone.

“In summary, pembrolizumab added to chemotherapy yields important survival gain; however, Garassino and colleagues report no improvement in HRQOL,” the article  said.

“As we strive to optimise our understanding of which patients are best served by initial checkpoint inhibitor therapy with or without chemotherapy, we must continue to focus not only on quantity of survival, but also its quality.”