Major response was observed to imatinib mesylate in KIT-mutated metastatic rectal melanoma (Hodi FS et al, J Clin Oncol 26:2046-2051, 2008). In the ASCO annual meeting in 2009ar, KIT mutations were reported to be present in 23% of acral and 15.2% of mucosal melanomas (Heinrich MC et al, J Clin Oncol 26:2008 abstr 9016). Nilotinib is a novel tyrosine kinase inhibitor (TKI) targeting KIT, PDGFR, and Bcr-Abl and inhibiting the proliferating of both imatinib-sensitive and imatinib-resistant cells in vitro. Phase I study of nilotinib alone and in combination with imatinib in patients with imatinib-resistant gastrointestinal stromal tumors (GIST) demonstrated significant activity (72% stable disease for nilotinib alone and 56% for nilotinib/imatinib combination) (Blay JY et al, J Clin Oncol 26:2008, abstr 10553).