Larotrectinib in TRK Fusion–Positive Cancers: Long-Term Follow-up
Posted: Sunday, August 1, 2021
The first-in-class, central nervous system–active TRK inhibitor larotrectinib demonstrated anticancer activity with durability and extended survival benefits in adult and pediatric patients with TRK fusion–positive cancer, according to Alexander Drilon, MD, of the Memorial Sloan Kettering Cancer Center and Weill Cornell Medical College, New York, and colleagues. These long-term follow-up data from a pooled analysis of three clinical trials presented during the virtual edition of the American Association for Cancer Research (AACR) Annual Meeting 2021 (Abstract CT020) highlight the importance of identifying NTRK gene fusions in patients with cancer.
“NTRK gene fusions are oncogenic drivers in various tumor types,” the investigators commented. “Larotrectinib was approved by the [U.S.] Food and Drug Administration in 2018 based on efficacy and safety outcomes in a primary analysis cohort of patients with [TRK fusion–positive] cancer from three clinical trials.”
Using data from these trials, the investigators identified patients with TRK fusion–positive cancer treated with larotrectinib twice daily. The primary analysis cohort comprised 55 patients with 17 different tumor types harboring NTRK1 (45%), NTRK2 (2%), or NTRK3 (53%) gene fusions. A total of 279 patients were enrolled in the expanded safety population.
The objective response rate was 80%, with 13 complete responses, 31 partial responses, 5 cases of stable diseases, and 6 cases of progressive diseases. With a longer follow-up, the best response improved from a partial to complete response in four patients. The median durations of response and progression-free survival were 35.2 and 25.8 months, respectively. The median duration of overall survival was not reached after a median follow-up of 32.5 months. The 36-month overall survival rate was 76%. In the expanded safety population, the majority of treatment-related adverse events were grade 1 or 2.
Disclosure: For full disclosures of the study authors, visit abstractsonline.com.