It has been shown that Compound 1 unexpectedly and potently inhibits TRK kinases, including all three forms of TRK: NTRK1, NTRK2, and NTRK3. Additionally it has been shown that Compound 1 potently inhibits oncogenic mutated forms of TRK kinases, including fusion proteins. By way of exemplification, Compound 1 potently inhibits the NTRK1 oncogenic fusion protein TPM3/NTRK1 in cellular assays. Compound 1 inhibits TRK kinase mediated tumor growth in vivo in a TPM3/NTRK1 xenograft model.