Persistent Ethnicity-Associated Disparity in Antitumor Effectiveness of Immune Checkpoint Inhibitors Despite Equal Access

We reviewed response to immune checkpoint inhibitors (ICI) of 207 patients with diagnoses of lung or head and neck cancer treated with chemotherapy/ICI combination therapy and ICI monotherapy between 2015 and 2020 at one of three clinical pavilions associated with the Dan L. Duncan Comprehensive Cancer Center at Baylor College of Medicine (Houston, TX). Two of these pavilions (Harris Health System and the Michael E. DeBakey Veterans Affairs Medical Center) serve large minority populations and provide equal access to care regardless of means. 174 patients had a diagnosis of lung cancer (non–small cell or small cell) and 33 had a diagnosis of head and neck squamous cell carcinoma (HNSCC). 38% self-identified as Black, 45% as non-Hispanic White, and 18% as Hispanic. The objective response rate (ORR) was similar for patients with lung cancer (35.057%) and HNSCC (30.3%; P = 0.894). The ORR for Hispanic and Black patients was lower compared with non-Hispanic White patients (H 27.0%, B 32.5%, W 38.7%; H vs. W P = 0.209; B vs. W P = 0.398). When considering only patients treated with ICI monotherapy, the ORR for Hispanic patients dropped further to 20.7% while the ORR of Black and non-Hispanic White patients remained about the same (B 29.3% and W 35.9%, H vs. W P = 0.133; B vs. W P = 0.419). Immune-related adverse events were the lowest in the Hispanic population occurring in only 30% of patients compared with 40% of patients in the Black cohort and 50% of the non-Hispanic White cohorts. SIGNIFICANCE: To our knowledge, this report is the first to compare ICI effectiveness within a diverse patient population with a substantial Black and Hispanic NSCLC and HNSCC patient population treated in the context of equal access to care. The data presented in this article suggests reduced effectiveness of ICI monotherapy in Hispanic patients and thereby underscores the need for improved access and representation of racial/ethnic minority patients in ICI clinical trials.