Usage of nivolumab and ipilimumab for recurrent or advanced malignant vaginal melanoma: a two-case series.

Immune checkpoint inhibitors help treat malignant melanoma, but show limited use in treating malignant vaginal melanoma, an aggressive, rare gynecological malignancy. We identified two patients treated with ipilimumab and nivolumab for vaginal melanoma; both were immunonegative for programmed cell death-ligand 1 and wild-type BRAF. Case 1, a 56-year-old female who underwent radical surgery for stage 1 malignant vaginal melanoma, experienced recurrence 15 months postoperatively. She briefly responded to ipilimumab and nivolumab combination therapy before showing disease progression. Tumor shrinkage occurred with nivolumab and local radiotherapy and, 45 months postoperatively, she survives with the melanoma. Case 2, a 50-year-old female, presented with a 4-cm blackish polypoid vaginal tumor with metastatic pelvic lymph nodes. She received ipilimumab and nivolumab combination therapy for stage III unresectable malignant vaginal melanoma. The vaginal tumor shrank after the third course of treatment, and the lymphadenopathy disappeared. The patient underwent radical surgery and is currently disease-free, using nivolumab for maintenance therapy. Both patients had immune-related adverse events coinciding with periods of high therapeutic efficacy of immune checkpoint inhibitors. Neoadjuvant therapy with immune checkpoint inhibitors and radiotherapy for immune checkpoint inhibitor resensitization may effectively treat advanced or recurrent vaginal melanoma.