Safety of First-Line Nivolumab Plus Ipilimumab in Patients With Metastatic NSCLC: A Pooled Analysis of CheckMate 227, CheckMate 568, and CheckMate 817.

Introduction: We characterized the safety of first-line nivolumab plus ipilimumab (NIVO+IPI) in a large patient population with metastatic NSCLC and efficacy outcomes after NIVO+IPI discontinuation owing to treatment-related adverse events (TRAEs).

Methods: We pooled data from three first-line NIVO+IPI studies (NIVO, 3 mg/kg or 240 mg every 2 wk; IPI, 1 mg/kg every 6 wk) in metastatic NSCLC (CheckMate 227 part 1, CheckMate 817 cohort A, CheckMate 568 part 1). Safety end points included TRAEs and immune-mediated adverse events (IMAEs) in the pooled population and patients aged 75 years or older.

Results: In the pooled population (N = 1255), any-grade TRAEs occurred in 78% of the patients, grade 3 or 4 TRAEs in 34%, and discontinuation of any regimen component owing to TRAEs in 21%. The most frequent TRAE and IMAE were diarrhea (20%; grade 3 or 4, 2%) and rash (17%; grade 3 or 4, 3%), respectively. The most common grade 3 or 4 IMAEs were hepatitis (5%) and diarrhea/colitis and pneumonitis (4% each). Pneumonitis was the most common cause of treatment-related death (5 of 16). Safety in patients aged 75 years or older (n = 174) was generally similar to the overall population, but discontinuation of any regimen component owing to TRAEs was more common (29%). In patients discontinuing NIVO+IPI owing to TRAEs (n = 225), 3-year overall survival was 50% (95% confidence interval: 42.6-56.0), and 42% (31.2-52.4) of 130 responders remained in response 2 years after discontinuation.

Conclusions: First-line NIVO+IPI was well tolerated in this large population with metastatic NSCLC and in patients aged 75 years or older. Discontinuation owing to TRAEs did not reduce long-term survival.