Discovery of the Next-Generation Pan-TRK Kinase Inhibitors for the Treatment of Cancer

The neurotrophic receptor tyrosine kinase (NTRK) genes including NTRK1, NTRK2, and NTRK3 encode the tropomyosin receptor kinase (Trk) proteins TrkA, TrkB, and TrkC, respectively. So far, two TRK inhibitors, larotrectinib sulfate (LOXO-101 sulfate) and entrectinib (NMS-E628, RXDX-101), have been approved for clinical use in 2018 and 2019, respectively. To overcome acquired resistance, next-generation Trk inhibitors such as selitrectinib (LOXO-195) and repotrectinib (TPX-0005) have been developed and exhibit effectiveness to induce remission in patients with larotrectinib treatment failure. Herein, we report the identification and optimization of a series of macrocyclic compounds as potent pan-Trk (WT and MT) inhibitors that exhibited excellent physiochemical properties and good oral pharmacokinetics. Compound 10 was identified via optimization from the aspects of chemistry and pharmacokinetic properties, which showed good activity against wild and mutant TrkA/TrkC in in vitro and in vivo studies.