Treatment Patterns of Real-World Patients with TRK Fusion Cancer Treated by US Community Oncologists

Neurotrophic tyrosine receptor kinase (NTRK) gene fusions are present across various tumor types with an estimated overall prevalence of less than 1%. Tropomyosin receptor kinase inhibitors (TRKis) block the constitutively activated tyrosine receptor kinase (TRK) fusion protein produced in cancers with NTRK gene fusions (NTRK+) from downstream signaling. Many treatment guidelines now include TRKis as first-line (1L) or subsequent treatment options for TRK fusion cancer.

This study aimed to assess treatment patterns subsequent to a finding of NTRK+ status among patients with TRK fusion cancer.

This was a one-time, retrospective, multi-site patient chart abstraction by oncology practices in the USA from June to September 2020. US medical oncologists from the Oncology Provider Extended Network (OPEN) who had treated patients with NTRK+ advanced/metastatic solid tumors abstracted information into electronic case report forms (eCRFs) for adult patients with advanced/metastatic solid tumors and a NTRK+ tumor test result with a known fusion partner. Data abstracted into eCRFs by oncologists included demographic, clinical, and treatment characteristics of patients with advanced/metastatic TRK fusion solid tumors. Responses were summarized using descriptive statistics. Median treatment durations across the lines of therapy were estimated by Kaplan-Meier time to discontinuation.

A total of 19 medical oncologists abstracted data from 110 patient charts. Median patient age at advanced/metastatic diagnosis was 62 years. The majority of patients were male (58.2%) and White (79.1%). Solid tumor types reported in at least 10% of the study cohort were lung (24.5%), cholangiocarcinoma (13.6%), pancreatic (10.9%), and colorectal (10.0%). Results for patients with hepatobiliary cancers (i.e., cholangiocarcinoma, pancreatic cancer, hepatocellular carcinoma) and colorectal cancer, and appendiceal cancer are also included. Median duration of 1L TRKi therapy was 16.8 months across all solid tumor types, whereas median duration of 1L was 5.6 months among patients receiving non-TRKi therapies (p = 0.017). Among the solid tumor types represented by at least 10% of the study population, median duration of 1L TRKi therapy was only reached in patients with pancreatic cancer (3.3 months). Median duration of TRKi in the second-line (2L) setting was 7.9 months overall, relative to 5.3 months among patients receiving non-TRKi therapies (p = 0.003). Across lung, cholangiocarcinoma, pancreatic, and colorectal cancers, the median durations of 2L TRKi therapy were 14.1, 6.0, 6.1, and 4.1 months, respectively.

Among patients with advanced/metastatic TRK fusion solid tumors, medical oncologists reported that approximately two-thirds initiated a TRKi during the study period. Treatment with a TRKi was longer in duration compared to non-TRKi treatment in 1L and 2L therapy. Additional research is needed to gain insight into the association between early TRKi therapy initiation and clinical outcomes in the real-world setting.