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.
It was worth noting that 31 inhibited GIST-T1 tumor growth (TGI = 81.5%) and even the BaF3-TEL-cKIT-T670I tumor progression (TGI = 41.9%, 1-resistant GISTs) at a dosage of 100 mg/kg/day without exhibiting apparent toxicity.