Association of immune-related adverse events and improved treatment outcomes across race/ethnicity in a diverse patient population

e21220 Background: The development of immune-related adverse events (irAEs) in patients treated with immune checkpoint inhibitors (ICIs) has been associated with improved clinical outcomes in advanced non-small cell lung cancer (NSCLC). However, how this association extends across race and ethnicity remains uncertain. In this study, we evaluated the association between the development of irAEs and treatment outcomes across different racial and ethnic groups treated at a single institution. Methods: We performed a retrospective chart review to identify irAEs and treatment outcomes in patients with advanced NSCLC who had received treatment with ICIs at our institution between 2015-2020. The incidence of irAEs across racial subgroups was compared using logistic regression analysis. Cox regression analysis was carried out to evaluate the associations between the development of irAEs and treatment outcomes [Overall Survival (OS) and Progression Free Survival (PFS)] in these subgroups. Results: We identified a total of 138 NSCLC patients who received treatment with ICIs, of whom 50% (69) identified as non-Hispanic Black (NHB) and 50% (69) as others, including 34% (47) as non-Hispanic White. The overall incidence of irAEs in the cohort was 28%, with no significant difference between NHB and other racial groups (29% vs. 27.5%). However, females [OR 2.3 (1.1-4.8)] and patients who did not have Medicare or private insurance (i.e had Medicaid or MassHealth) were found to have a higher incidence of irAEs [OR 2.7 (1.2-5.7)]. With a median follow-up time of 363 days, the proportion of patients who were progression-free was greater in patients who had experienced irAEs than in those who did not experience irAEs [HR for time to progression 0.46 (0.23 – 0.92)]. The association between irAEs and improved PFS in NHB patients was similar to the overall population [median PFS 246 vs. 181; HR 0.87 (0.58-1.29)]. Higher ECOG status, higher Charlson Comorbidity Index and receiving ICIs as 2 nd or subsequent line therapy were independently associated with worse PFS. Conclusions: Our single-institution study demonstrated a similar incidence of irAEs in patients with NSCLC across different racial and ethnic groups. As in prior studies, patients undergoing treatment with ICIs and experiencing irAEs had significantly better outcomes. We found that the association between the development of irAEs and improved treatment outcomes was independent of race and ethnicity, supporting the importance of making unbiased treatment recommendations without regard to these factors. [Table: see text]