Vitiligo, an autoimmune skin disorder, was evaluated in 49 metastatic melanoma patients treated with an immunotherapy regimen of maintenance biotherapy (mBT) following induction concurrent biochemotherapy (cBCT). Patients receiving mBT demonstrated a stable or better response to cBCT. The mBT regimen consisted of outpatient subcutaneous injections of low-dose IL-2 (1 MIU/m(2)) 5/7 days weekly, GM-CSF (125 mcg/m(2)) 14 days monthly, and high-dose pulses of in-patient continuous infusion decrescendo IL-2 (54 MIU/m(2)) over 48 hours monthly for the first 6 months and every 2 months thereafter. The majority of patients had poor prognostic features. Forty-nine patients were without evidence of vitiligo at the start of mBT. Of these, 21 patients (43%) developed vitiligo during mBT and had a median overall survival from the start of mBT of 18.2 months (95% CI, 12.3-N/A) compared to 8.5 months (95%CI <6.7-12.7) for 28 non-vitiligo patients (P=0.027). Six of 21 vitiligo patients (29%) expressed IgG antibody titers to tyrosinase-related protein-2 compared to four of 28 non-vitiligo patients (14%) (P=NS). The development of vitiligo in metastatic melanoma patients on cBCT/mBT immunotherapy correlates with a better therapeutic outcome.