Why moles disappear with anti-melanoma therapies?

Naevus lightening is a fascinating phenomenon found in patients on BRAF inhibitors and MEK inhibitors combination therapy (BiMiC) and checkpoint immunotherapy.
We have recently published a study unravelling the mystery underlining this phenomenon. We biopsied 7 lightened naevi from metastatic melanoma patients on either BiMiC or checkpoint immunotherapy such as pembrolizumab. Under the microscope, we saw that most of the lightened naevi under immunotherapy showed complete regression, mimicking vitiligo-like lesions. On the other hand, the lightened naevi in those on BiMiC therapy showed incomplete regression, with 2 of 3 cases showing junctional/compound naevus remaining in the biopsied lesions.

If you might be interested in reading more about lightened naevi under systemic anti-cancer therapies, please visit the journal.