Cross sectional analysis of long-term overall survival among patients taking immune checkpoint inhibitor drugs.

[BACKGROUND] Immune checkpoint inhibitors (ICIs) have transformed the landscape of tumor therapy. Yet, little is known about the collective long-term survival from these therapies. We sought to characterize long-term survival.

[METHODS] In a cross-sectional analysis of US FDA oncology ICI drug approvals (2011-2023), we retrieved data from supporting registration trials. We examined the percentage of study participants surviving at 12-, 24-, 36-, and 60-months follow-up; the American Society of Clinical Oncology (ASCO) Value Framework Tail of the Curve calculation; and the correlation between the longest time with 10 % of patients still at-risk and the difference in the percentage of patients in each treatment group alive.

[RESULTS] Out of 88 included approvals, 20 (22.7 %) qualified for ASCO's tail of the curve bonus. Twenty-seven studies (30.7 %) did not report OS at 12 months; 44 (50.0 %) did not report OS at 24 months; 60 (68.2 %) did not report OS at 36 months; and 78 (88.6 %) did not report OS at 60 months. We found no correlation between the last time that at least 10 % of patients were still at-risk and the difference in the percentage of patients in each group still alive at that time-point (R=0.1; p = 0.30). Among 81 studies that reported an OS curve, the longest time with at least 10 % of participants at-risk was a median of 30 months. The median difference in survival was 8 %.

[CONCLUSIONS] Few registration trials testing ICI oncology therapies report long-term overall survival data. The gathering and reporting of this information should be incentivized so that the value of these drugs for patients can be more readily assessed.