Differences in Treatment Outcomes among EGFR Mutations, Fusion Oncogenes, and Other Actionable Alterations in NSCLC: A Large Japanese Real-World Cohort.

e20712 Background: Molecular targeted therapies have transformed the management of non–small cell lung cancer (NSCLC) with actionable genomic alterations. However, direct comparisons of treatment outcomes across different genomic subtypes within a single real-world cohort remain limited. We evaluated the relative efficacy and safety of targeted therapies across major actionable genomic alterations in a large Japanese real-world population. Methods: This multicenter retrospective study included 810 consecutive Japanese patients with advanced or recurrent NSCLC harboring actionable genomic alterations who received molecular targeted therapy between 2017 and 2023. Patients were classified into three genomic groups: EGFR mutations (Group A, n = 659), fusion oncogenes involving ALK/ROS1/RET (Group B, n = 106), and other actionable alterations including MET exon 14 skipping, BRAF V600E, and KRAS G12C (Group C, n = 45). Treatment outcomes, including objective response rate (ORR), progression-free survival (PFS), overall survival (OS), and safety, were analyzed using Kaplan–Meier methods and multivariable Cox regression. Results: The median follow-up was 24.9 months overall (Group A 25.6, Group B 27.3, Group C 16.1). A total of 580 progression events and 398 deaths were observed. ORR differed significantly among groups (74.1% in Group A, 85.8% in Group B, and 68.9% in Group C; P = 0.014). Median PFS was 17.5 months in Group A, 42.5 months in Group B, and 9.2 months in Group C (P < 0.001). Median OS was not reached in Group B, compared with 39.3 months in Group A and 22.7 months in Group C (P < 0.001). In multivariable analyses adjusting for clinical covariates, genomic subgroup remained independently associated with both PFS and OS, with fusion-driven tumors demonstrating consistently superior outcomes. EGFR-mutated tumors showed intermediate outcomes, whereas Group C exhibited limited efficacy and higher treatment discontinuation due to adverse events. Conclusions: In this large Japanese real-world cohort, a clear hierarchy of therapeutic benefit across actionable genomic alterations was observed. Fusion oncogene–driven NSCLC derived exceptional and durable benefit from targeted therapy, EGFR-mutated tumors demonstrated intermediate outcomes, and MET exon 14 skipping, BRAF V600E, and KRAS G12C mutations remained associated with limited efficacy and higher toxicity. These findings underscore the clinical importance of genomic subtype–based treatment strategies and highlight unmet needs in selected molecular subsets.