Havrdova E, et al. – Five–year efficacy and safety of alemtuzumab in treatment–naive patients with active relapsing–remitting MS (RRMS) (CARE–MS I) were assessed. The authors concluded that through 5 years in the absence of continuous treatment, alemtuzumab provided durable efficacy, with most patients not receiving additional courses.

• Alemtuzumab-treated patients received treatment courses at baseline and 12 months later.
• They could enter an extension with as-needed alemtuzumab retreatment for relapse or MRI activity after the core study.
• Annualized relapse rate (ARR), 6-month confirmed disability worsening (CDW; ≥1-point Expanded Disability Status Scale [EDSS] score increase [≥1.5 if baseline EDSS = 0]), 6-month confirmed disability improvement (CDI; ≥1-point EDSS decrease [baseline score ≥2.0]), no evidence of disease activity (NEDA), brain volume loss (BVL), and adverse events (AEs) were included as assessments.

• The authors enrolled most alemtuzumab-treated patients (95.1%) completing CARE-MS I in the extension; 68.5% received no additional alemtuzumab treatment.
• In years 3, 4, and 5, ARR remained low (0.19, 0.14, and 0.15).
• 79.7% were free of 6-month CDW over years 0-5; 33.4% achieved 6-month CDI.
• In years 3, 4, and 5, most patients (61.7%, 60.2%, and 62.4%) had NEDA.
• Median yearly BVL improved over years 2-4, remaining low in year 5 (years 1-5: -0.59%, -0.25%, -0.19%, -0.15%, and -0.20%).
• In the extension, exposure-adjusted incidence rates of most AEs declined relative to the core study.
• At year 3, thyroid disorder incidences peaked and subsequently declined.