Evaluating patient-reported outcomes in the treatment of metastatic non-small-cell lung cancer with pembrolizumab plus pemetrexed–platinum

The study evaluated treatment outcomes reported by patients with metastatic non-small-cell lung cancer (mNSCLC) who were treated by pembrolizumab (Keytruda) and pemetrexed (Alimta) and platinum chemotherapy. The authors found that adding pembrolizumab to pemetrexed-platinum chemotherapy improved health-related quality of life (HRQOL) compared to placebo and chemotherapy.

mNSCLC spreads to distant organs in the body. Platinum-based chemotherapy such as cisplatin (Platinol) or carboplatin (Paraplatin) is effective against such conditions but has several side effects. Previously, pembrolizumab improved HRQOL in patients with mNSCLC compared to platinum-based chemotherapy. Recently, pembrolizumab also improved survival in such patients in combination with pemetrexed plus platinum, compared to placebo. However, the effects of this combination on patients’ HRQOL are unknown.

The study included 602 adult patients with previously untreated mNSCLC. 402 patients received pemetrexed–platinum chemotherapy with pembrolizumab. 206 patients received pemetrexed-platinum chemotherapy with a placebo. Patients were followed up for 10.5 months on average. Patients' HRQOL was analyzed through questionnaires. It was scored by the GHS/QOL scale where higher scores denoted better HRQOL.

GHS/QOL scores at the start of therapy were similar between both groups. They were also maintained after 12 weeks in both groups. At week 21, GHS/QOL score was improved in the pembrolizumab group and worsened in the placebo group, compared to the beginning.

Worsening in scores occurred among 26% of patients on pembrolizumab compared to 38% of patients on placebo during this time. Whereas, score improvements happened in 30% of patients on pembrolizumab and 23% on placebo. Worsening of cough, chest pain and breathing trouble happened in 7 months on average in patients on placebo. The pembrolizumab group faced no such symptoms as of the time of analysis. The placebo group had 19% higher risks of worsening such symptoms compared to pembrolizumab.

The study concluded that combing pembrolizumab with pemetrexed-platinum maintained HRQOL in patients with previously untreated mNSCLC. It improved GHS/QOL scores compared to placebo-chemotherapy at 21 weeks.

This study was funded by Merck Sharp & Dohme, the manufacturer of pembrolizumab. Long-term effects of this combination therapy on PROs were not discussed.