Abstract A087: Clinical outcomes in Black patients with EGFR-mutated NSCLC treated with osimertinib

Abstract Introduction: Epidermal growth factor receptor (EGFR) gene mutations are present in about 15% of non–small cell lung cancer (NSCLC) cases in the U.S. The FLAURA study, in which the tyrosine kinase inhibitor (TKI) Osimertinib demonstrated a median PFS of 18.9 months, set the current standard in the U.S. for front-line treatment of advanced NSCLC with sensitizing EGFR mutations. However, Black patients were greatly underrepresented in the FLAURA study (<1% of trial population) and two retrospective single-institution studies suggest inferior survival in Black patients with EGFR-mutant NSCLC treated with TKIs versus (vs.) other races. Research is needed using large real-world cohorts to evaluate real-world progression-free survival (rwPFS) and overall survival (OS) in Black patients with EGFR-mutant NSCLC to determine whether they derive comparable benefit from Osimertinib as other races. Methods: The nationwide Flatiron Health Electronic Health Record (EHR)-derived de-identified database was used to analyze data from 1503 patients with advanced NSCLC bearing an EGFR exon 19 deletion or L858R mutation who received front-line Osimertinib. The de-identified data originated from 280 US cancer clinics (∼800 sites of care). Patients were stratified by race (Black vs. White) and characteristics were compared using chi-square, Fisher’s exact, and t-tests. Kaplan-Meier curves estimated rwPFS (based on clinician documentation of progression) and OS in months (m). Differences in survival were assessed between Black and White patients using multivariable Cox proportional hazards models that adjusted for age, gender, EGFR subtype, histology, diagnosis year, smoking history, performance status, insurance status, and socioeconomic index. Results: In our cohort, comprised of 179 Black and 1324 White patients with EGFR-mutant NSCLC, median age and percentage with a smoking history did not differ by race. However, Black patients were more likely to be female (74.3% vs. 66.4%, p=0.03), possess an exon 19 deletion tumor (74.3% vs. 58.3%, p<0.001) or be in a low socioeconomic index category (30.2% vs. 8.7%, p<0.001) than White patients. Median rwPFS did not significantly differ between Black and White patients treated with Osimertinib (15.1 m vs. 14.1 m, HR 0.91, p=0.39). Similarly, no significant difference in OS was observed among Black patients treated with Osimertinib as compared to Whites (29.2 m vs. 32.5 m, HR 1.07, p=0.57). Conclusion: This real-world analysis of one of the largest cohorts of Black patients with EGFR-mutant NSCLC to date, did not observe differences in rwPFS and OS as compared to White patients following front-line Osimertinib therapy. Efforts should be made to ensure all patients receive mutational testing upfront so they can receive optimal first line therapy. Citation Format: Neel Belani, Farsha Rizwan, Jill Hasler, Jessica Bauman, Khadijah Mitchell, Hossein Borghaei, Joseph N Bodor. Clinical outcomes in Black patients with EGFR-mutated NSCLC treated with osimertinib [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr A087.