Patti et al. Subcutaneous Interferon β-1a May Protect against Cognitive Impairment in Patients with Relapsing-Remitting Multiple Sclerosis: 5-Year Follow-up of the COGIMUS Study.PLoS One. 2013 Aug 30;8(8):e74111.
OBJECTIVE: To assess the effects of subcutaneous (sc) interferon (IFN) -1a on cognition over 5 years in mildly disabled RRMSers.
METHODS: MSers aged 18-50 years with RRMS (Expanded Disability Status Scale score ≤4.0) who had completed the 3-year COGIMUS study underwent standardized magnetic resonance imaging, neurological examination, and neuropsychological testing at years 4 and 5. Predictors of cognitive impairment at year 5 were identified using multivariate analysis.
RESULTS: Of 331 MSers who completed the 3-year COGIMUS study, 265 participated in the 2-year extension study, 201 of whom (75.8%; sc IFN β-1a three times weekly: 44 µg, n = 108; 22 µg, n = 93) completed 5 years’ follow-up. The proportion of MSers with cognitive impairment in the study population overall remained stable between baseline (18.0%) and year 5 (22.6%). The proportion of MSers with cognitive impairment also remained stable in both treatment groups between baseline and year 5, and between year 3 and year 5. However, a significantly higher proportion of men than women had cognitive impairment at year 5 (26.5% vs 14.4%, p = 0.046). Treatment with the 22 versus 44 µg dose was predictive of cognitive impairment at year 5 (hazard ratio 0.68; 95% confidence interval 0.48-0.97).