Natural interferon‐beta in chronic progressive multiple sclerosis: results after 2 years of treatment and 2 years of follow up

Seventeen chronic progressive multiple sclerosis patients were treated with natural interferon-beta (IFN-β) for 2 years, thereafter they were followed up for 2 years. IFN-β was given 1 million IU/day i.m. for 1 week, then 3 million IU daily for 3 weeks followed by a maintenance regimen of 2 million IU twice a week for 23 months. Kurtzke Expanded Disability Status Scale score was 5.5 at entry and did not change at the end of the first year. It increased to 5.8 at the end of the second year and to 6.5 at the end of the follow-up. Three patients worsened after 1 year, six after 2 years and nine at the end of the follow-up. Brain MRI was performed at entry and after 1 year: mean lesion score increased by 13.4%. MRI changes were not correlated with clinical course. Natural IFN-β seemed to have some beneficial effect when high doses were given: this effect tended to disappear after IFN-β was reduced, followed by a more severe disease progression after its withdrawal.