Dasatinib in Treating Patients With Locally Advanced or Metastatic Mucosal Melanoma, Acral Melanoma, or Vulvovaginal Melanoma That Cannot Be Removed By Surgery

Inclusion Criteria for Pre-Registration (Step 0): * Histologically or cytologically confirmed melanoma of 1 of the following subtypes: * Acral melanoma (defined as occurring on the palms, soles, or subungual sites) * Melanoma arising from the vagina and/or vulva * Melanoma arising on other mucosal surface (not vagina or vulva) * Unresectable locally advanced or metastatic disease * c-KIT mutation identified by polymerase chain reaction (PCR) and sequencing meeting 1 of the following criteria: * At least 1 mutation in exon 9, 11, 13, 17, or 18 * At least 1 mutation in an exon not listed above and approved by central reviewer * Metastatic tumor blocks are required for the evaluation of KIT mutations or amplifications * Prior radiotherapy to a measurable lesion allowed provided there is radiographic evidence of progression of that lesion * No other concurrent malignancies except basal cell or squamous cell skin cancer, carcinoma in situ of the cervix, ductal or lobular carcinoma in situ of the breast, or other malignancies from which the patient has been continuously disease-free for ≥ 5 years * ECOG performance status 0-1 Exclusion Criteria for Pre-Registration (Step 0): * Prior treatment with targeted therapies directed to c-KIT/PDGFR (e.g., imatinib or sunitinib) * Ocular melanoma * Evidence of bleeding diathesis * Clinically significant psychiatric illness or social situations that would limit compliance with study requirements * Clinically significant cardiov…