Survival without toxicity for cisplatin plus pemetrexed versus cisplatin plus gemcitabine in chemonaïve patients with advanced non-small cell lung cancer: A risk-benefit analysis of a large phase III study

Background: In a large phase III study, cisplatin and pemetrexed had non-inferior efficacy and better tolerability compared with cisplatin and gemcitabine in chemonaïve patients with non-small cell lung cancer (NSCLC). The current analysis characterised the clinical benefit (i.e. survival) relative to clinical risk (i.e. drug-related toxicity) of the doublets. Patients and methods: A total of 1669 patients (of 1725 randomised) received 500 mg/m² pemetrexed IV followed by 75 mg/m² cisplatin IV on day 1 or gemcitabine 1250 mg/m² on days 1 and 8 and 75 mg/m² cisplatin on day 1, administered every 3 weeks for up to 6 cycles. Survival without toxicity (i.e. clinical benefit to risk) was defined as the time from randomisation to the first occurrence of any grade 3 or 4 drug-related toxicity or death, and was analysed using Kaplan-Meier and Cox methods. Results: In the overall patient population, survival without grade 3 or 4 drug-related toxicity was significantly longer for patients treated with cisplatin and pemetrexed versus cisplatin and gemcitabine (HR = 0.70; P < 0.001), as was survival without grade 4 drug-related toxicity (HR = 0.83; P < 0.001). For patients with non-squamous NSCLC, survival without toxicity with cisplatin and pemetrexed was superior to cisplatin and gemcitabine for grade 3 or 4 drug-related toxicity (HR = 0.64; P < 0.001) and for grade 4 drug-related toxicity (HR = 0.77; P < 0.001), whereas no treatment-arm difference was observed in the squamous subgroup. Conclusions: Patients with non-squamous NSCLC treated with front-line cisplatin and pemetrexed have superior survival without toxicity (i.e. clinical benefit-to-risk profile) compared with patients treated with cisplatin and gemcitabine.