[P06.145] Alemtuzumab Induces a Sustained Reduction in Disability in Patients with Relapsing Remitting Multiple Sclerosis

Alasdair J. Coles, Cambridge, United Kingdom, CAMMS223 Study Group, San Antonio, TX

OBJECTIVE: To assess the effect of alemtuzumab vs. interferon beta-1a (INFB-1a) on sustained reduction in disability (SRD). BACKGROUND: CAMMS223, a randomized, open-label, rater-blinded, phase 2 study, showed alemtuzumab to be significantly more effective than IFNB-1a at reducing risk of sustained accumulation of disability and relapses, as well as improving scores on the Expanded Disability Status Scale (EDSS). SRD assesses the stability of EDSS improvement during the 36 month study period. DESIGN/METHODS: Patients with early, active RRMS (n=334) were randomized 1:1:1 to IFNB-1a (44mcg SC 3x/week); 24mg/day alemtuzumab; or 12mg/day alemtuzumab. Entry criteria included baseline EDSS 3.0, 2 MS episodes within 2 years, and 1 enhancing lesion on MRI. Alemtuzumab was IV administered for 5 days at Month 0, 3 days at Month 12, and in some patients, 3 days at Month 24. A post hoc analysis of patients with an EDSS >0 (94.9% of all patients) assessed the effect of alemtuzumab on SRD. SRD is defined as a 1 point decrease in EDSS score lasting 6 months for patients with EDSS scores >0. RESULTS: The cumulative proportion of alemtuzumab patients attaining SRD by 36 months was 41.5% (95% CI: 35.0, 48.7) compared to 26.9% (95% CI: 18.5, 38.3) of IFNB-1a patients (Kaplan Meier estimation.) Alemtuzumab patients were at least twice as likely to have experienced SRD as IFNB-1a patients at months 12 (p<.05), 24 and 36 (both pvalues<.01 using Cox proportional hazard model.) Notable alemtuzumab adverse events included infusion reactions, secondary autoimmune disorders, and predominantly mild to moderate infections. CONCLUSIONS/RELEVANCE: During the 36 month treatment period, patients who received alemtuzumab were twice as likely to experience a sustained decrease in disability as patients receiving 3x weekly IFNB-1a. These data suggest alemtuzumab may halt progression of disability and stably reverse pre-existing neurological impairment, but further study is needed. Supported by: Genzyme
Category - MS and Related Diseases - Clinical Science

Wednesday, April 29, 2009 4:00 PM

Poster Session VI: Multiple Sclerosis: Therapeutics I (4:00 PM-7:00 PM)