Etoposide: more effective and less bone-marrow toxic than standard immunosuppressive therapy in systemic vasculitis?

In two patients suffering from ANCA-positive systemic vasculitis (one from Wegener's granulomatosis, the other from microscopic polyangiitis), who were both resistant to or could not tolerate standard immunosuppressive therapy, complete clinical and biochemical remission was obtained within few months, treating with cyclic etoposide. Etoposide therapy was found to be significantly less bone marrow toxic than standard immunosuppressive therapy.