Updated estimates of eligibility and response: Immune checkpoint inhibitors.

e14613 Background: Immune checkpoint inhibitors (ICIs) have notably changed the landscape of systemic treatment of advanced and metastatic cancers in the last decade. We previously estimated the eligibility for and responses to ICIs, but since then, there have been multiple approvals for additional indications. As such, we have updated these estimates to include all approvals, as of December 2023. Methods: For eligibility, we used death data from the American Cancer Society’s Cancer Facts and Figures. Deaths was used as a stand-in for eligibility because these therapies are often given in later lines. Data from the peer-reviewed literature was used to further refine specific tumor type estimates (e.g., the percentage of lung cancers that are non-small cell and small cell lung cancer). For each tumor type, we multiplied the response rates reported in the FDA’s package insert by the number of deaths for each respective tumor type. When multiple drugs were approved for the same indication, we used the highest response rate. Results: Eleven ICI drugs were approved for 88 different indication approvals in the advanced/metastatic setting between 2015 and 2023. These approvals were for 20 general tumor types. The estimated eligibility for ICIs increased from 1.54% in 2011 to 55.47% in 2023. The tumor types with the highest eligibility in 2023 were non-small cell lung cancer with PDL1 status of 50% (13.28%) or less and PDL1 status >50% (4.42%), solid tumors TMB-h (6.81%), and hepatocellular (4.82%). The estimated response to ICIs increased from 0.14% in 2011 to 19.60% in 2023. The tumor types with the highest contribution to response estimates in 2023 were non-small cell lung cancer with PDL1 status of 50% (4.78%) or less and PDL1 status >50% (1.99%), solid tumors TMB-h (2.72%), and renal cell carcinoma (1.95%). Conclusions: We find that the estimated eligibility for and response to ICIs has increased since their introduction in 2011. Our estimates are an upper bound since many people are not eligible due to contraindications or healthcare coverage. Both the response and eligibility were driven by certain tumor types, including non-small cell lung cancer (either PDL1 high or PDL1 low). Patients with these types of tumors made up about one-third of the estimated response and eligibility. Solid tumors TMB-h, hepatocellular and renal cell carcinoma were other tumors with high eligibility and response, but other tumor types had low eligibility and response. While many patients have benefited from ICIs, half of patients with advanced or metastatic cancers are either not eligible or likely do not respond. Table: see text