Enhanced Survival Associated with Vitiligo Expression during Maintenance Biotherapy for Metastatic Melanoma

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/m2) 5/7 days weekly, GM-CSF (125 mcg/m2) 14 days monthly, and high-dose pulses of in-patient continuous infusion decrescendo IL-2 (54 MIU/m2) 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.