Safety and Efficacy Outcomes of Early Cessation of Anti-PD1 Therapy in Patients 80 Years or Older: A Retrospective Cohort Study

Abstract

Older patients have similar immune checkpoint inhibitor efficacy and rates of adverse events as younger patients, but appear to have decreased tolerability, particularly in the oldest patient cohort (>80 years), often leading to early cessation of therapy. We aimed to determine whether early discontinuation impacts efficacy of anti-PD-1 therapy in patients ≥80 years old. In this retrospective, multicenter, international cohort study, we examined 773 patients with 4 tumor types who were at least 80 years old and treated with anti-PD-1 therapy. We determined response rate, overall survival (OS), and progression-free survival (PFS) in patients who discontinued therapy early (<12 months) for reasons other than progression or death. We used descriptive statistics for demographics, response, and toxicity rates. Survival statistics were described using Kaplan Meier curves. Median (range) age at anti-PD-1 initiation was 83.0 (75.8-97.0) years. The cancer types included were melanoma (n = 286), non-small cell lung cancer (NSCLC) (n = 345), urothelial cell carcinoma (UCC) (n = 108), and renal cell carcinoma (RCC) (n = 34). Of these, 102 met the primary endpoint of <12 months to discontinuation for reasons other than death or progression. Median PFS and OS, respectively, for these patients were 34.4 months and 46.6 months for melanoma, 15.8 months and 23.4 months for NSCLC, and 10.4 months and 15.8 months for UCC. This study suggests geriatric patients who have demonstrated therapeutic benefit and discontinued anti-PD-1 therapy at less than 12 months of duration for reasons other than progression may have durable clinical benefit without additional therapy.