Adding a MEK inhibitor to BRAF inhibitor treatment for metastatic melanoma is associated with a significant reduction in the risk of cutaneous squamous cell carcinoma and other cutaneous toxic effects, new data suggests.

A retrospective cohort study in 185 patients with unresectable stage IIIC and IV melanoma showed those treated with BRAF inhibitors dabrafenib or vemurafenib in combination with a MEK inhibitor had zero cases of cutaneous squamous cell carcinoma, verrucal keratosis or Grover disease but a 40% incidence of folliculitis, according to a paper published online July 22 in JAMA Dermatology.

In contrast, the rates of cutaneous squamous cell carcinoma were significantly higher among patients treated with either dabrafenib or vemurafenib alone (26.1% and 36.1%, respectively), as was the incidence of Grover disease (42.9% and 38.9%) and verrucal keratosis (66.4% and 72.2%).

“Recognition of the variety of cutaneous toxic effects associated with these different therapies, including the predisposing risk factors for their development, is important with the purpose of ensuring appropriate rapid intervention and thereby abrogating the need to delay or even withhold these essential treatments,” wrote Dr. Giuliana Carlos of Westmead Hospital, Sydney, and coauthors (JAMA Dermatology 2015, July 22 [doi:10.1001/jamadermatol.2015.1745]).

The study was supported by the Westmead Medical Research Foundation. Three authors reported travel support or consultancies with pharmaceutical companies, but there were no other conflicts of interest declared.