ABSTRACT
Since 1993, the field of multiple sclerosis (MS) therapeutics has changed dramatically. Positive results of well-designed and well-conducted prospective multicenter, randomized, double-blind, placebo-controlled phase III trials have been published. This led to approval by North American and European regulatory agencies of interferon beta1b,[1-3] interferon beta-1a[4,5] and glatiramer acetate[6] for relapsing-remitting MS. The same process has led to approval in Europe of interferon beta-1b for secondary progressive MS.[7]
Thousands of patients have already used one or more of these disease-modifying agents. The experience has not always been positive. This may not be surprising, considering that the level of efficacy of the interferons is limited to a one-third reduction in relapse rate and an approximately 10% absolute reduction of the proportion of patients with sustained worsening by at least 1 point on the Kurtzke expanded disability status score (EDSS).[1,3-8] In daily practice, it appears that some patients respond well to current therapies, while others are much less responsive. Current therapies are also limited by the need for parenteral administration and by local and systemic adverse effects. Consequently, there is a clear and urgent need for more effective, more convenient, and better tolerated therapies.
