Abstract

BACKGROUND:

There are no published MRI studies comparing interferon beta 1b (IFNbeta-1b) and glatiramer acetate (GA) for treatment of relapsing multiple sclerosis (MS).

OBJECTIVE:

To compare the efficacy of IFNbeta-1b and GA for suppression of MS disease activity as evidenced on frequent brain MRI.

METHODS:

A total of 75 patients with relapsing-remitting MS or clinically isolated syndromes were randomized to standard doses of IFNbeta-1b or GA and followed by monthly brain MRI for up to 2 years with a protocol optimized to detect enhancement. The primary outcome was the number of combined active lesions (CAL) per patient per scan during the first year, which included all enhancing lesions and nonenhancing new T2/fluid-attenuated inversion recovery (FLAIR) lesions. Secondary outcomes were the number of new lesions and clinical exacerbations over 2 years.

RESULTS:

Baseline characteristics were similar between the groups. The primary outcome showed similar median (75th percentile) CAL per patient per scan for months 1-12, 0.63 (2.76) for IFNbeta-1b, and 0.58 (2.45) for GA (p = 0.58). There were no differences in new lesion or clinical relapses for 2 years. Only 4.4% of CAL on monthly MRI scans were nonenhancing new T2/FLAIR lesions.

CONCLUSION:

Patients with relapsing multiple sclerosis randomized to interferon beta 1b or glatiramer acetate showed similar MRI and clinical activity.