RET-IN-22 (compound 17b) is a potent, selective and orally active RET inhibitor with an IC 50 of 20.9 nM and 18.3 nM for wild-type RET and RET-V804M , respectively. RET-IN-22 shows highly selective profile to most kinases, especially to EGFR and VEGFR2. RET-IN-22 has anticancer effects.