Zeteletinib (BOS-172738; DS-5010) hemiadipate is an orally active, selective RET kinase inhibitor with nanomolar potency against RET and >300-fold selectivity against VEGFR2. Zeteletinib hemiadipate shows exquisite potency for the wild type RET , RET V804M/L gatekeeper mutants, and the most common oncogenic RET mutation M918T. Zeteletinib hemiadipate has potent antitumor activity.