A tropomyosin receptor kinase (TRK) inhibitor with potential antineoplastic activity. Upon administration, utatrectinib binds to TRK, thereby preventing the neurotrophin-TRK interaction and subsequent TRK activation. This may eventually result in an inhibition of tumor cell proliferation in TRK-expressing tumor cells. TRK, a receptor tyrosine kinase activated by neurotrophins, is mutated in a variety of cancer cell types and plays an important role in tumor cell growth, invasion and survival.