Clinical benefit with tebentafusp in a patient with GNAQ mutant metastatic blue nevus-associated melanoma.

Melanoma arising in association with a blue nevus (BN) is rare but has molecular similarities to uveal melanoma (UM), including GNAQ/11 mutations. Tebentafusp was recently approved for UM based on improved overall survival in a phase 3 study. We hypothesized that tebentafusp may be active in BN-associated melanoma. Here, we present a case of metastatic BN-associated melanoma with rapid response and ~1 year of disease control on tebentafusp. We also explore molecular and histological features of secondary resistance. Our case highlights that PD-1-resistant melanomas should be screened for GNAQ/11 mutations, as tebentafusp may be a treatment option in this extremely rare disease.