GIST cells carrying KIT -del557-558/T670I or KIT -InsAY502-503/V654A mutations were resistant to imatinib, while PKC412 significantly inhibited autophosporylation of these mutants.
Herein, by introducing adaptive elements into the inhibitor core structure, we undertake the structure-based development of type II hybrid inhibitors to overcome gatekeeper drug-resistant mutations in cSrc-T338M, as well as clinically relevant tyrosine kinase KIT-T670I and Abl-T315I variants, as essential targets in gastrointestinal stromal tumors (GISTs) and chronic myelogenous leukemia (CML).
KRAS and KIT Gatekeeper Mutations Confer Polyclonal Primary Imatinib Resistance in GI Stromal Tumors: Relevance of Concomitant Phosphatidylinositol 3-Kinase/AKT Dysregulation.
These were PDX models harboring primary and secondary <i>KIT</i> and additional mutations; <i>KIT</i> exon 11 (p.Y570_L576del), <i>KIT</i> exon 17 (p.D816E), and <i>PTEN</i> (p.T321fs) mutations in GIST-RX1 from a patient who was unresponsive to imatinib, sunitinib, and sorafenib, and <i>KIT</i> exon 11 (p.K550_splice) and <i>KIT</i> exon 14 (p.T670I) mutations in GIST-RX2 and <i>KIT</i> exon 9 (p.502_503insYA) and <i>KIT</i> exon 17 (p.D820E) mutations in GIST-RX4 from patients with imatinib and imatinib/sunitinib resistance, respectively.
Compound 24 displays good antiproliferative effects against c-KIT T670I mutant-driven GIST cell lines (GIST-T1/T670I and GIST-5R) and also exhibits suitable in vivo pharmacokinetic profiles as well as dose-dependent antitumor efficacy.