Systemic vasculitis associated with vemurafenib treatment

RATIONALE Vemurafenib, an inhibitor of mutated B-rapidly accelerated fibrosarcoma, is frequently used in the treatment of melanoma and Erdheim-Chester disease (ECD) patients. Inflammatory adverse effects have been increasingly reported after vemurafenib treatment. PATIENT CONCERNS AND DIAGNOSE We report 6 cases of vemurafenib-associated vasculitis, of whom a personal case of a 75-year-old man with history of ECD who developed purpura and rapidly progressive pauci-immune glomerulonephritis during treatment with vemurafenib. INTERVENTION In the 5 others cases from the literature, all patients presented skin vasculitis, and with joint involvement in 60% of them. Vemurafenib treatment was stopped (n = 3), continued at reduced doses (n = 1), or continued at the same dose (n = 2). OUTCOMES Three patients (50%) received corticosteroids combined with cyclophosphamide (n = 1), and all achieved remission of vasculitis. One patient experienced vasculitis relapse after vemurafenib therapy was restarted. LESSONS Systemic vasculitis is a rare vemurafenib-associated adverse event that may be life-threatening.