Although it remains unclear how either beta-1a or beta-1b interferons ( IFNs ) work in multiple sclerosis, these therapies have been well established in relapsing remitting multiple sclerosis ( RRMS ). Currently, IFNs' therapies are also the first line treatment for secondary progressive multiple sclerosis ( SPMS ), since other drugs, such as Mitoxantrone, have a worse risk/benefit profile. A major unanswered question is whether and to what extent interferons are really effective in secondary progressive multiple sclerosis.

The main objective of the review was to verify whether IFNs in patients with secondary progressive multiple sclerosis are more effective than placebo in reducing the number of patients who experience disability progression during the 2-3 years follow-up.

Among the pertinent literature, only five studies met the criteria of the inclusion in the review, comprising a total of 3122 participants ( 1829 treated with IFN and 1293 with placebo ).

Overall, these results have shown that interferons are unable to retard the progression once it is established, making INFs not useful in the secondary progressive phase of the disease.

The well known adverse events related to interferons' treatment such as injection site reactions, influenza like syndrome, and leukopenia occurred frequently also in secondary progressive multiple sclerosis patients, while serious and life-threatening adverse events were not increased in the treated group of patients.

Because this review has considered well designed studies with a high number of patients, the authors believe that its results give conclusive evidence on the clinical efficacy of IFN beta versus placebo in patients with secondary progressive multiple sclerosis.

Source: The Cochrane Library, 2012

XagenaMedicine2012