Randomized study of interferon beta-1a, low-dose azathioprine,and low-dose corticosteroids in multiple sclerosis

BackgroundStudies evaluating interferon beta (IFNβ) for multiple sclerosis (MS) showed only partial efficacy. In many patients, IFNβ does not halt relapses or disability progression. One strategy to potentially enhance efficacy is to combine IFNβ with classical immunosuppressive agents, such as azathioprine (AZA) or corticosteroids, commonly used for other autoimmune disorders.ObjectiveThe Avonex–Steroids–Azathioprine study was placebo-controlled trial and evaluated efficacy of IFNβ-1a alone and combined with low-dose AZA alone or low-dose AZA and low-dose corticosteroids as initial therapy.MethodsA total of 181 patients with relapsing–remitting MS (RRMS) were randomized to receive IFNβ-1a 30 μg intramuscularly (IM) once weekly, IFNβ-1a 30 μg IM once weekly plus AZA 50 mg orally once daily, or IFNβ-1a 30 μg IM once weekly plus AZA 50 mg orally once daily plus prednisone 10 mg orally every other day. The primary end point was annualized relapse rate (ARR) at 2 years. Patients were eligible for enrollment i...