Background: Neurotrophic tyrosine receptor kinase (NTRK) gene fusions have been identified as oncogenic drivers in a diverse array of tumor types including lung cancer. Larotrectinib is a first-in-class, highly selective, central nervous system (CNS)-active tropomyosin receptor kinase (TRK) inhibitor approved for the treatment of adult and pediatric patients (pts) with TRK fusion cancer, with an objective response rate (ORR) of 78% across multiple non-CNS cancers (McDermott et al, ESMO 2020). Here, we report the updated data on pts with lung cancer treated with larotrectinib. Methods: Pts with lung cancer harboring a NTRK gene fusion enrolled in two clinical trials (NCT02576431 and NCT02122913) were identified for this analysis. Larotrectinib 100 mg PO BID was administered on a continuous 28-day schedule until disease progression, withdrawal, or unacceptable toxicity. Response was assessed by the investigator per RECIST v1.1. Results: As of July 20, 2020, a total of 20 pts with TRK fusion-positive lung cancer (19 with non-small cell lung cancer and 1 with small cell lung cancer) were enrolled. Median age was 48.5 years (range 25.0–76.0). The gene fusions involved NTRK1 (n = 16; 80%) or NTRK3 (n = 4; 20%). Pts were heavily pre-treated with a median of 3 systemic therapies (range 0–6). Among 15 evaluable pts, the confirmed ORR was 73% (95% CI 45–92): 1 complete response, 10 partial responses (PR), 3 stable disease (SD) and 1 progressive disease (PD). The median time to response was 1.8 months. Among 8 evaluable pts with baseline measurable and non-measurable CNS metastases, the ORR was 63% (95% CI 25–91): 5 PR, 2 SD, and 1 PD. In all evaluable pts, the 12-month rates for duration of response and progression-free survival were 81% and 65%, respectively. Median overall survival was 40.7 months (95% CI 17.2 to not estimable) at a median follow-up of 16.2 months. Duration of treatment ranged from 0.03+ to 51.55+ months. Adverse events (AEs) were predominantly Grade 1–2. Treatment-related AEs were reported in 16 pts, of which 2 experienced Grade 3 events (myalgia, hypersensitivity, weight increase). There were no treatment discontinuations due to AEs. Conclusions: These data confirm that larotrectinib is highly active with rapid and durable responses, extended survival benefit, and a favorable long-term safety profile in pts with advanced lung cancer harboring NTRK gene fusions, including in pts with CNS metastases. These results underscore the importance of screening for NTRK gene fusions in pts with lung cancer. Clinical trial information: NCT02576431 and NCT02122913