PHILADELPHIA – The rates of new or growing brain lesions slowed in both treatment-naive and relapsed patients with relapse-remitting multiple sclerosis who took the monoclonal antibody alemtuzumab in two phase III trials with follow-up data out to 3 years.
Loss of brain volume also slowed over the 3-year period based on changes in brain parenchymal fraction (BPF), reported Dr. Douglas Arnold, a neurologist at the Montreal Neurological Institute and Hospital of McGill University.
The data are consistent with clinical disease activity endpoints previously reported in the CARE-MS I and II (Comparison of Alemtuzumab and Rebif Efficacy in Multiple Sclerosis) studies indicating that alemtuzumab could be used to reduce relapse rates in patients with first-line treatment-refractory relapsing-remitting multiple sclerosis (RRMS), and in those who are treatment naive.
At 3 years follow-up in the CARE-MS I study, 336 of 370 patients with RRMS who were treatment-naive and had received alemtuzumab 12 mg at baseline and again at 12 months in the randomized, controlled phase III trial were found to have no gadolinium-enhancing (Gd-enhancing) lesions. In this same cohort, 325 patients had no new or enlarging T2 lesions at year 3. Overall, no MRI activity was observed in 354 patients at 2 years and in 326 at 3 years.
The CARE-MS II study included 421 RRMS patients who had relapsed after undergoing another first-line therapy. At year3, 364 patients were free from Gd-enhancing lesions, and 361 had no new or enlarging T2 lesions. No MRI activity could be detected in 402 patients at 2 years and in 361 at 3 years.
In the CARE-MS I trial, 18% were re-treated with alemtuzumab in year 3; 20% of the CARE-MS II patients were re-treated with the monoclonal antibody during the third year, while less than 3% of all participants were treated with another disease-modifying therapy in year 3.
"Given that the majority of patients received no treatment for 2 years, the results support the durable efficacy of alemtuzumab in RRMS," Dr. Arnold said at the annual meeting of the American Academy of Neurology.
The treatment was also associated with a reduction in loss of brain volume over the 3-year study period, according to BPF data. In both patient populations, the median percentage reduction in BPF in the third year was less than observed in years 1 and 2: 0.19% and 0.10%, respectively, for year 3, compared with 0.59% and 0.48%, respectively, for the first year, and 0.25% and 0.22% in the second.
The data "support the positive benefit-risk profile of alemtuzumab in RRMS," Dr. Arnold said. Previous studies have shown that alemtuzumab had a slightly higher risk of infusion-associated reactions when compared with interferon beta-1a treatment: 77% of the alemtuzumab group vs. 66% in the interferon beta-1a group, although the infections were reported as mild to moderate.
Dr. Arnold disclosed he has received compensation from Bayer, Eli Lilly, Genentech, Genzyme, GlaxoSmithKline, Novartis, and others. Genzyme and Bayer supported CARE-MS I and II.
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