Comparison of Long-Term Survival Between Nivolumab Plus Ipilimumab and Nivolumab Plus Ipilimumab With Chemotherapy in Advanced NSCLC: A Multicenter Retrospective Cohort Study.

Introduction: Pivotal clinical trials have reported the survival benefits of both nivolumab plus ipilimumab (NI) and nivolumab plus ipilimumab with 2 cycles of platinum-based chemotherapy (NICT) compared with chemotherapy. However, real-world evidence comparing NI and NICT with long-term follow-up remains limited. Methods: We retrospectively analyzed 181 patients treated with NICT or NI across 13 institutions in Japan. The primary end points were median overall survival (OS) and the 36-month OS rate. Secondary end points included progression-free survival (PFS), objective response rate, disease control rate, and treatment-related adverse events (TRAEs). To reduce treatment-selection bias, 1:1 propensity score matching was performed using 11 covariates. Results: In the post-propensity score matching cohort (47 pairs; n = 94; median follow-up, 42.6 and 44.1 months), the median PFS was 8.7 months with NICT versus 4.7 months with NI (hazard ratio [HR] 0.86; Conclusions: With more than 40 months of follow-up, NICT was associated with higher response rates and a higher incidence of TRAEs of grade 3 or higher than NI, without a clear PFS or OS advantage. Adding 2-cycles of chemotherapy may enhance early disease control but at the cost of increased toxicity, and this balance should be considered when selecting treatment for patients for whom tolerability is a major concern.