Sulfasalazine is a well-established, safe drug with known anti-inflammatory and immunomodulatory properties. It has been used as a treatment for inflammatory bowel disease for a number of decades. More recently, it also proved to have a favourable impact on rheumatoid arthritis. The results of a large Mayo Clinic–Canadian cooperative, double-blind, placebo-controlled, phase III trial of sulfasalazine in active MS have been reported. A total of 199 ambulatory MS patients with active disease were treated with sulfasalazine up to two grams a day or placebo and were evaluated for a minimum of three years (mean follow-up 3.7 years). Even though the short-term (two-year) response seemed to be favourable, the drug ultimately failed to slow or prevent disability progression as measured by the primary outcome (confirmed worsening of the EDSS score by at least 1 point on two consecutive three-month visits).

In the opinion of the Committee, sulfasalazine does not have benefit in MS.