KIT and melanoma: Trials conducted with Imatinib mesylate, an inhibitor of KIT and other RTKs, in patients with c-KIT–mutant melanoma, have reported median times to disease progression of approximately 3 months that are significantly lower than the time to progression when Imatinib is used to treat gastrointestinal stromal tumors (GIST) (median time to progression of 18 months).