BACKGROUND: BRAF inhibitor-based therapies have been shown to induce cutaneous 
toxicities, with onset generally in the first 8-26 weeks of therapy.
OBJECTIVES: To determine whether cutaneous toxicities persist in patients who 
have remained on BRAF inhibitor-based therapies for longer than 52 weeks, and 
therefore whether ongoing dermatology assessment is required.
METHODS: All patients treated with the BRAF inhibitors vemurafenib or dabrafenib 
or combination BRAF inhibitor and mitogen-activated protein kinase kinase (MEK) 
inhibitor therapy at Westmead Hospital, Sydney, Australia underwent regular 
dermatological assessments for the duration of therapy. All patients enrolled in 
a clinical trial, and 18% of patients in the compassionate access scheme 
underwent a baseline assessment prior to commencement of therapy and every 
4-8 weeks thereafter. Patients' adverse events were recorded in a specific 
database.
RESULTS: Patients continued to develop cutaneous adverse events after 52 weeks 
of continuous therapy. Patients on single-agent BRAF inhibitor therapy suffered 
from Grover disease (45%), plantar hyperkeratosis (45%), verrucal keratosis 
(18%) and even cutaneous squamous cell carcinoma (16%). The most frequent 
adverse event seen in patients in the combination BRAF and MEK inhibitor group 
was an acneiform eruption (40%).
CONCLUSIONS: Patients on BRAF inhibitor-based therapies need to continue to have 
regular dermatological follow-up independent of the duration of their therapy.