Background on an Retrospective Analysis of Larotrectinib in TRK-Fusion Thyroid Cancers

Theodore W. Laetsch, MD, an attending physician at the Cancer Center at Children’s Hospital of Philadelphia, discusses which trials were used for the retrospective study of the TRK inhibitor larotrectinib (Vitrakvi) for the treatment of TRK-fusion cancers, including thyroid cancers.

According to Laetsch, data was pulled primarily from the adult phase 1 trial (NCT02122913) of larotrectinib with general patients, with or without the presence of a TRK fusion, the pediatric SCOUT study (NCT02637687), and the adult and adolescent phase 2 NAVIGATE (NCT02576431) trial. Both the SCOUT and NAVIGATE trials are ongoing. Patients included in the retrospective ranged from pediatric patients to elderly patients. Additionally, according to Laetsch, the safety analysis was not limited to only patients with TRKfusions.

0:08 | It's pulled from 3 different trials. So, the adult phase 1 trial of larotrectinib with general patients, with or without the presence of a TRK fusion, and then the pediatric SCOUT study which enrolled patients, again initially with or without the presence of a TRK fusion but was subsequently amended to only enroll patients with TRK fusions for the phase two portion. And then the adult and adolescent phase 2 trial called NAVIGATE. Both of those latter trials are still ongoing with patients. And so, this has included a group of patients that ranged from very young, less than a month of age until elderly adults, and with a wide variety of different histologies. Looking at the safety outcome, it didn't restrict the analysis to patients with TRK fusions and included patients with or without TRK fusions, all patients who enrolled on those trials.