FCN-098

FCN-098 is a highly active, selective, oral second-generation small-molecule inhibitor targeting tropomyosin receptor kinases TRKA, TRKB, and TRKC. These kinases are encoded by the NTRK1, NTRK2, and NTRK3 genes. FCN-098 is designed to inhibit both wild-type and drug-resistant mutant forms of these kinases by competitively binding to their kinase domains at the ATP-binding site. This action blocks phosphorylation of the TRK fusion protein and downstream signaling (notably ERK1/2), thereby inhibiting tumor cell proliferation and survival. The drug was developed as a response to resistance mutations that arise with first-generation TRK inhibitors in patients with solid tumors harboring NTRK gene fusions[1][4][6]. FCN-098 has been investigated primarily for advanced solid tumors with NTRK fusions[3][6].