Introduction

Encorafenib (BraftoviTM) is indicated for the treatment of adult patients with unresectable or metastatic melanoma with a BRAF V600 mutation, in combination with binimetinib (Mektovi ®) (1). Encorafenib, as a BRAF inhibitor, blocks the MAPK signaling pathway of the V600-mutated constitutively active BRAF molecule. Binimetinib, as a MEK inhibitor, blocks the downstream signaling pathway through the MEK molecule. In addition, MEK inhibitors reduce side effects by reduction of paradoxical activation of the MAPK pathway by BRAF inhibition (2). Approximately 40% of all metastatic melanoma tumors harbour an oncogenic BRAF V600 mutation (3). Encorafenib combined with binimetinib, slows or stops the enhanced cell growth and has shown to improve overall and progression-free survival among patients with metastatic melanoma (4). When combined, the recommended dose of encorafenib is 450 mg once daily, and of binimetinib 45 mg twice daily. The management of adverse reactions may require dose reduction, temporary interruption or treatment discontinuation of both or either one of the drugs (1). Although the product label provides recommendations in case of adverse events, there is no specific treatment recommendation in case of an overdose (1). We describe the course of a case with a chronic toxicity during 16 days of double dose of encorafenib as well as the followed approach, which could be taken into account when treating a patient with an encorafenib intoxication.