A phase II study of interferon-alpha for the treatment of refractory Churg-Strauss syndrome.

OBJECTIVE: Uncontrolled vasculitis is the major cause of early death in Churg-Strauss syndrome and standard therapy is not always effective. This study was carried out to examine the safety and efficacy of interferon-alpha for induction of remission in patients with refractory Churg-Strauss syndrome.

METHODS: In a prospective open-label trial, seven patients with Churg-Strauss syndrome refractory to cyclophosphamide or methotrexate received interferon-alpha (3 million. I.U. 3 times weekly s.c.) for induction of remission. Primary end point was the successful induction of remission. Prednisolone was tapered according to the study protocol.

RESULTS: All seven patients entered remission after 3 months of treatment. Five patients reached complete remission while in two patients, residual asthmatic complaints persisted. The mean Birmingham Vasculitis Activity Score (BVAS) decreased from 6.4 (+/-2.8) to 0 (+/-0) (p=0.017). Clinical improvement in response to interferon-alpha allowed to taper concomitant prednisolone according to the protocol from a mean dose of 20.4 mg/d (+/-13.3) to 6.9 mg/d (+/-1.9) (p=0.068). During a follow up of 6 months all patients remained in remission. In one patient, leukencephalopathy without clinical symptoms was seen on MRI after 61 months of treatment, as previously reported. In this cohort, no other cases of leukencephalopathy were observed during long-term follow-up. Constitutional symptoms related to the injection of interferon-alpha responded well to paracetamol. A transient leukopenia was found in two patients.

CONCLUSION: Interferon-alpha appears to be an effective and well-tolerated treatment for induction of remission in patients with refractory Churg-Strauss syndrome.