Q-TWiST Analysis to Assess Benefit–Risk of Pembrolizumab in Patients with PD-L1–Positive Advanced or Metastatic Non-small Cell Lung Cancer

OBJECTIVES: Pembrolizumab monotherapy showed significantly longer overall survival and fewer treatment-related adverse events compared to chemotherapy in patients with advanced or metastatic non-small cell lung cancer (NSCLC) with programmed death ligand-1 (PD-L1)–positive tumors in the first-line setting in KEYNOTE (KN)-024 and in those previously treated in KN010. The objective of this analysis was to assess the benefit–risk of pembrolizumab in terms of quality-adjusted survival amongst patients in these trials. METHODS: The Quality-adjusted Time Without Symptoms of disease progression or Toxicity of treatment (Q-TWiST) analysis was used to compare treatments. Survival time was partitioned into three health states: with toxicity before disease progression, without toxicity before disease progression, and disease progression until death. Health state utilities were estimated using EuroQol-5 Dimensions, 3 Levels (EQ-5D-3L) data collected in the trials. Q-TWiST was calculated as the utility-weighted sum of the mean health state durations. Trial data analyzed included the primary analysis and subsequent data cutoffs. The base-case analysis was based on the most recent analysis of the trials. RESULTS: Patients randomized to pembrolizumab had 2.49 months greater Q-TWiST (P value < 0.001) compared to those randomized to platinum-based chemotherapy at a follow-up of 24 months in KN024, and 2.29 months greater Q-TWiST (P value < 0.001) compared to docetaxel over 30 months follow-up in KN010. Results across the trial analyses showed an increase in trend for the Q-TWiST improvement of pembrolizumab over time. CONCLUSIONS: Pembrolizumab showed significant improvement in Q-TWiST compared to chemotherapy in advanced or metastatic NSCLC in both previously untreated and treated patients. The benefits of pembrolizumab continued to accrue with longer follow-ups.