Pan-Cancer Survival Impact of Immune Checkpoint Inhibitors in a National Healthcare System

Area of Science:

• Oncology
• Immunotherapy
• Real-world evidence

Background:

• The overall survival benefit of immune checkpoint inhibitors (ICIs) in real-world populations, especially those with limited life expectancy or underrepresented in clinical trials, remains unclear.
• Assessing the health system-wide impact of ICIs is crucial for understanding their broad utility.

Purpose of the Study:

• To determine the health system-wide survival impact of immune checkpoint inhibitors (ICIs).
• To evaluate ICI effectiveness across diverse patient subgroups within a national healthcare system.

Main Methods:

• A retrospective cohort study identified patients receiving ICIs (PD-1/PD-L1 or CTLA-4 inhibitors) from 2010-2023 in the Veterans Health Administration (VHA) system.
• Matched historical controls who received non-ICI systemic therapy prior to ICI approval were used for comparison.
• Overall survival was analyzed using Cox regression with matching weights, and cumulative life-years gained were calculated based on restricted mean survival times.

Main Results:

• The study included 27,322 patients in the ICI cohort and 69,801 in the historical control cohort.
• ICIs demonstrated a significant overall survival benefit across most cancer types, including non-small cell lung cancer (NSCLC) and melanoma, with notable heterogeneity.
• The benefits of ICIs were consistent across patient age, comorbidity, and racial subgroups, contributing to an estimated 15,859 life-years gained system-wide within 5 years.

Conclusions:

• Immune checkpoint inhibitors have led to a substantial increase in survival across a national health system.
• These findings extend to patient subgroups often underrepresented in clinical trials, highlighting the broad applicability of ICIs.