RESUMEN
Alemtuzumab, a humanized monoclonal antibody, has shown efficacy for relapsing-remitting multiple sclerosis (MS) in phase 2 and phase 3 trials. Compared with subcutaneous interferon beta-1a, alemtuzumab significantly reduced the risk for accumulation of disability and the rate of relapse, and improved mean disability level from baseline. Notable safety and tolerability concerns include infusion-associated reactions, infections of predominantly mild-to-moderate severity, and autoimmune adverse events, principally thyroid disorders and immune thrombocytopenia. As emerging therapies such as alemtuzumab are approved for the treatment of MS, nurses specializing in the care of MS patients will make increasingly significant contributions to the education of patients, caregivers, and other health-care providers about these therapies' efficacy, tolerability, safety, and administration. This article reviews the phase 2 and phase 3 efficacy and safety results for alemtuzumab, with an emphasis on the role of nurses in communication about this treatment option for those with MS.
RESUMEN
BACKGROUND: Alemtuzumab is a humanised monoclonal antibody that depletes lymphocytes, causing long-term immunomodulation. In a 3-year, rater-blinded phase 2 study (the CAMMS223 study) in patients with relapsing-remitting multiple sclerosis (RRMS), alemtuzumab reduced relapse rate and the risk of sustained accumulation of disability compared with subcutaneous interferon beta-1a, and the mean expanded disability status scale (EDSS) score of the alemtuzumab cohort improved compared with baseline. Adverse events included infusion-associated reactions, predominantly mild to moderate infections, thyroid disorders, and immune thrombocytopenia. In this study, we further analysed the CAMMS223 data with the aim of determining whether demographic and baseline disease-related characteristics affect the beneficial effects of alemtuzumab. Additionally, we aimed to describe a new outcome measure in multiple sclerosis research: sustained reduction in disability. METHODS: 334 treatment-naive patients with active, early RRMS were randomly assigned in a 1:1:1 ratio to receive interferon beta-1a (44 µg subcutaneously three times per week), or 24 mg per day or 12 mg per day alemtuzumab intravenously for 2 or 3 annual cycles. We analysed freedom from clinical disease activity (CDA; defined as no relapses and no sustained accumulation of disability) and occurrence of sustained reduction in disability (SRD; a ≥1 point decrease on the EDSS sustained for 6 consecutive months for patients with a baseline EDSS ≥2), and analysed efficacy outcomes for subgroups based on age, sex, geographic region, MRI-T1 brain volume, MRI-T2 lesion volume, disease duration, number of previous relapses within 2 years, and EDSS. FINDINGS: 322 patients were analysed. 161 of 215 patients treated with alemtuzumab were free of CDA at 36 months (Kaplan-Meier estimate 71·8%, 95% CI 63·1-78·8%) compared with 52 of 107 patients treated with interferon beta-1a (42·6%, 32·4-52·4%; hazard ratio [HR]=0·31, 0·20-0·46; p<0·0001). For the 199 patients with a baseline EDSS score greater than or equal to 2, SRD was more likely (HR=2·61, 1·54-4·43; p=0·0004) among patients treated with alemtuzumab (66 of 133 patients, Kaplan-Meier estimate 51·6%, 95% CI 43·2-60·7%) than patients treated with interferon beta-1a (15 of 66 patients, 27·2%, 17·2-41·4%). All disability and relapse outcomes showed evidence of beneficial effects of alemtuzumab compared with interferon beta-1a across all analysed patient subsets, and no subgroup of patients consistently responded better than others to alemtuzumab. INTERPRETATION: Alemtuzumab reduced disease activity compared with interferon beta-1a in most of the analysed subgroups. Significantly greater numbers of patients experienced sustained improvement in disability after treatment with alemtuzumab than interferon beta-1a. The efficacy offered by alemtuzumab is a substantial advance in the treatment of multiple sclerosis. FUNDING: Genzyme and Bayer Schering Pharma.
