[Open trial of the effectiveness of interferon beta 1a (Avonex) in multiple sclerosis. Clinical assessment using...

The aim of the study was to evaluate clinical efficacy and safety of interferon beta 1A (Avonex) in the Polish population of remitting-relapsing multiple sclerosis (RR MS) patients.

The study was organized as an open, multi-center trial with 126 RR MS patients. Intramuscular Avonex was administered once a week in the dose of 30 mcg. The treatment duration was 24 months. The annual relapse rate (ARR), proportion of relapse-free patients, the average change in EDSS scores between the baseline and the study completion, and the proportion of patients who deteriorated on the EDSS scale during the treatment were used as evaluation parameters. Additionally, to obtain quantitative data, the 9HPT and 25 FW test results were taken into account.

A significant decrease in the ARR was noted in the course of treatment (from 1.47 in the 2-year period preceding the study to 0.38). The mean EDSS score for the whole group was higher by 0.13 on the study completion. However, patients without motor deficits (EDSS < 2.0) at baseline improved by 0.25 on the EDSS during the treatment, while those with motor deficits (EDSS 2.0 to 4.0)--deteriorated by 0.65. In the period under study 45.8% of the patients remained stable, 26.7% improved and 27.5% deteriorated on the EDSS. The mean duration of the 9HPT test performance increased by 0.67 sec for the dominant, and by 0.97 sec for the non-dominant hand from the baseline to post-treatment evaluation. But again, in patients without any motor deficits the mean time of 9HPT test performance was shorter post-treatment than at baseline for the dominant and non-dominant hand, while in those with motor deficits it was longer for both hands on the study completion. The mean performance time on the 25 FW test was longer by 0.74 sec on the study completion for the whole group, but in patients without motor deficits the increase in the 25 FW performance time was significantly smaller than in those with baseline EDSS scores ranging from 2.0 to 4.0. Avonex did not cause any significant abnormalities in laboratory parameters monitored during the treatment, and no significant side effects were observed except for flu-like symptoms following an Avonex injection.

Results of this study confirmed a beneficial effect of 1FNb 1A (Avonex) in the dose of 30 mcg per week on the clinical status of MS patients. The findings indicate a better treatment outcome in patients with less pronounced neurological deficits at baseline.