Dr. van Tilburg on Larotrectinib in TRK+ Pediatric Cancers

Cornelis M. van Tilburg, MD, PhD, pediatric oncologist, Heidelberg University Hospital and German Cancer Research Center, discusses the activity of larotrectinib (Vitrakvi) in patients with TRK fusion—positive cancers who have brain metastases or primary central nervous system (CNS) tumors.

In one analysis presented at the 2019 ASCO Annual Meeting, treatment with larotrectinib at either 100 mg or 150 mg twice daily led to an overall response rate of 94% in pediatric patients with TRK fusion-positive cancers, says van Tilburg. Responses were durable, and the treatment was found to be well tolerated, he adds.

Of a subset of 28 children and adolescents with non-CNS TRK fusion—­positive cancer enrolled in 2 larotrectinib clinical trials (NCT02637687 and NCT02576431), 12 patients (35%) achieved a complete response to larotrectinib at the data cutoff of July 30, 2018, while 18 (59%) had a partial response and 2 (6%) had stable disease. The median time to response was approximately 1.8 months with the agent. Thirty-three patients (87%) remained on treatment or underwent surgery with curative intent.

Furthermore, the median duration of response had not been reached at a median follow-up of 8.9 months. At a median follow-up of 10.7 months for progression-free survival (PFS), the median PFS had not been reached. At the median follow-up of 12.3 months for overall survival (OS), median OS had not been reached.