Larotrectinib for TRK Fusion–Positive Gastrointestinal Cancer
Posted: Thursday, October 21, 2021
Larotrectinib, a first-in-class, central nervous system–active TRK inhibitor, demonstrated rapid responses with high survival rates and a favorable safety profile in patients with TRK fusion–positive gastrointestinal cancer, according to Jordan D. Berlin, MD, of Vanderbilt University, Nashville, and colleagues. The results from an expanded data set of the phase II NAVIGATE trial, which were published in the journal Annals of Oncology, support testing for NTRK gene fusions in patients with gastrointestinal cancer, particularly in those with microsatellite instability–high (MSI-H) colorectal cancer.
A total of 18 patients with metastatic TRK fusion–positive gastrointestinal cancer who received larotrectinib were enrolled. Of the 10 patients with colorectal cancer, 7 had MSI-H disease, 2 had microsatellite-stable disease, and 1 had an unknown phenotype.
Among all evaluable patients, the objective response rate was 41%; this included one patient with a complete response, six with a partial response (one pending confirmation), seven with stable disease, two with progressive disease, and one with an undetermined response. The median duration of the time to response in the six confirmed responders was 1.9 months. The median duration of response was 5.5 months. At a median follow-up of 20.3 months, the median duration of progression-free survival was 5.4 months. The median duration of overall survival was 14.1 months, at a median follow-up of 7.8 months.
The objective response rate was 50% in patients with colorectal cancer; this included one patient with a complete response, four with a partial response (one pending confirmation), and five with stable disease. The median durations of response, progression-free survival, and overall survival were 15.5, 5.5, and 29.4 months, respectively, in this patient population.
Most adverse events were grade 1 or 2. A total of 11 patients experienced treatment-related adverse events. Grade 3 or 4 treatment-related adverse events were observed in two patients. No treatment discontinuations due to treatment-related adverse events were reported.
Disclosure: For full disclosures of the study authors, visit annalsofoncology.org.