Long-term effectiveness of glatiramer acetate in clinical practice conditions

Abstract

Glatiramer acetate currently represents one of the main treatments for relapsing-remitting multiple sclerosis (RRMS). However, the information available about its long-term effect in clinical practice is still limited. Thus, this multicenter retrospective cohort study aimed to assess the long-term effectiveness of glatiramer acetate in this setting. The study population included RRMS patients treated with glatiramer acetate for at least 5years after its marketing authorization and the primary endpoint was long-term clinical effectiveness, defined as absence of disability progression for at least five consecutive years. A total of 149 patients were included into the study, who had received glatiramer acetate for a mean of 6.9±1.4years (5years, n=149; 6years, n=112; 7years, n=63; 8years, n=32; 9years, n=21). More than 85% of patients remained free from disability progression through years 1 to 9 of glatiramer acetate treatment, and 75.2% showed absence of disability progression for at least five consecutive years. Expanded Disability Status Scale (EDSS) scores were maintained, with most patients showing stable/improved EDSS and 92.6% sustaining EDSS <6. Decreased annual relapse rates and increased proportion of relapse-free patients were maintained during the whole glatiramer acetate treatment compared to the year prior to its authorization (p<0.001). The number of gadolinium-enhanced T1-weighted lesions also decreased from pre-glatiramer-acetate assessment to last follow-up whilst on glatiramer acetate (p<0.05). In conclusion, administration of glatiramer acetate shows long-term clinical effectiveness for RRMS treatment; its effect under clinical practice conditions slowed disability progression and reduced relapse occurrence for up to 9years.