Interferon beta-1A: new preparation. A short-term impact on the course of multiple sclerosis

(1) Interferon beta-1a is the second interferon beta to be marketed (after interferon beta-1b) for the treatment of multiple sclerosis. (2) The cornerstone of the clinical file is a single placebo-controlled trial that showed, in the first two years of treatment, that interferon beta-1a slowed disease progression in patients with multiple sclerosis progressing through exacerbations, who were able to walk unaided. The longer-term action is not known. (3) Interferon beta-1a has not been compared with interferon beta-1b, which has no demonstrated action on progression of disability linked to the disease. (4) Like interferon beta-1b, the systemic adverse effects of interferon beta-1a are mainly a 'flu-like syndrome and the onset of neutralising interferon antibodies, the clinical consequences of which are unknown. Indirect comparison suggests that local tolerability at the injection site could be better with interferon beta-1a. (5) Treatment with interferon beta-1a is simpler than with interferon beta-1b, as the former can be kept at room temperature before reconstitution and is given in a single weekly injection instead of three.