Toxic epidermal necrolysis in a patient receiving vemurafenib for treatment of metastatic malignant melanoma

Funding sources: none. Conflicts of interest: M.R.M. has received research funding and honoraria from Roche for consultancy and for speaking at sponsored meetings. L.F. has received honoraria to speak at a Roche‐sponsored meeting. Dear Editor, Vemurafenib is a specific inhibitor of V600‐mutant BRAF and is indicated as monotherapy for the treatment of adults with BRAF V600 mutation‐positive unresectable or metastatic melanoma. In the short time that it has been available, it has developed a well‐recorded adverse event profile, specifically of cutaneous toxic effects.1 2 Toxic epidermal necrolysis (TEN) is a dermatological emergency with a predicted mortality rate of 3–90% dependent on a well‐documented illness severity score (SCORTEN).3 We describe the first case report in the literature of TEN associated with vemurafenib, and its management. A 73‐year‐old woman was diagnosed with metastatic melanoma (Breslow thickness 7·6 mm) of the plantar aspect of her left foot in June 2011. She underwent primary surgical excision and left inguinal lymphadenectomy (one of seven lymph nodes involved). Mutation analysis (cobas® 4800; Roche Diagnostics Limited, Burgess Hill, U.K.) showed a V600E mutation in BRAF, and the patient was started on vemurafenib at the standard dose of 960 mg twice daily. In addition to vemurafenib the patient was taking sodium valproate (200 mg daily) for a previous seizure unrelated to her melanoma.