The incidence of new primary melanomas in patients treated with checkpoint inhibitors for prior metastatic melanoma is low, Sydney dermatologists and oncologists report after a review of cases.

Even when they do occur, new primary melanomas (NPMs) are usually detected at an early stage and tend to have features associated with favourable prognosis, according to the Melanoma Institute Australia and University of Sydney-led team.

In a retrospective analysis, the researchers examined the frequency and clinicopathologic characteristics of NPMs in long-term survivors of high-risk melanoma treated with immune checkpoint inhibitors.

Among 1047 patients identified from two databases, just 14 NPMs were detected in 13 patients — a cumulative incidence rate of 1.3%.