Quality-adjusted time without symptoms or toxicity (Q-TWiST) analysis of a Phase III randomized trial to compare the benefit of gefitinib versus pemetrexed/carboplatin for epidermal growth factor receptor-mutated non-small cell lung cancer

Abstract

Background:> In an open-label, Phase III randomized study, gefitinib was found to be superior to pemetrexed-platinum in terms of progression-free survival in patients with epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer. In this analysis, we have assessed the efficacy of gefitinib over pemetrexed-platinum using quality-adjusted time without symptoms or toxicity (Q-TWiST) of treatment analysis method. Methods: The overall survival in each arm was partitioned into the following three health states: time spent in Grade 2 or above toxicity after randomization and before progression (TOX state), time spent after randomization and before progression without Grade 2 or above toxicity (TWiST state), and time spent after progression (REL state). The mean Q-TWiST was calculated for each arm using utility coefficients of 0.65 for TOX, 0.71 for TWiST, and 0.67 for REL states. The difference in Q-TWiST and the 95% confidence interval (CI) of the difference were calculated using a nonparametric bootstrap.P= 0.05 was considered statistically significant. Results: The mean TOX duration (37.6 vs. 16.2 days,P Conclusion: The mean Q-TWiST of patients in the gefitinib arm was similar to that of patients in the pemetrexed-carboplatin arm. These results challenge the superiority of sequencing gefitinib followed by chemotherapy over pemetrexed-carboplatin followed by gefitinib in terms of Q-TWiST.