Alemtuzumab(ALEM) is an anti-CD52 monoclonal antibody approved for the treatment of active Multiple Sclerosis(MS) which showed an overall high efficacy in clinical trials, also in the highly active subgroup of patients.
The aim of this multicenter obervational study is to evaluate efficacy and safety of ALEM-treatment in a population of aggressive MS naïve-patients at year 2 and 3 after a complete cycle of treatment.
We conducted a multicenter prospective observational study in a cohort of ALEM-naïve MS patients. Clinical and neuroradiological parameters were collected from patients’ clinical records in 26 Italian MS Centers from October 2015 to May 2020.
133 naïve patients were treated with ALEM: 60,2% females, mean age 31,4(± 8,9) years, mean disease duration 18,5(± 22,7) months, mean follow-up(FU) 34,2(± 12,1) months, median EDSS 3(0-6,5), ARR in the year preceding treatment 1,8 (± 0,9), mean number of brain T2/FLAIR-hyperintense lesions 29,8 (± 20,8) and mean number of Gd-enhancing lesions 3,4(± 5,1). Regarding ALEM efficacy, we report data obtained after the first complete cycle of treatment (2 ALEM-courses) because the occurrence of disease activity between the first and second course is not indicative of a therapeutic failure. 99 and 61 over 133 patients have at least 24 and 36 months FU respectively: 97% and 82% were relapse-free, ARR was 0,02 and 0,1, 92.9% and 82% were MRI activity-free and 97,7% and 91,8% progression-free with median EDSS of 2,0 and 1,5 (IQR 1 – 2,5) at year 2 and 3. The mean time to first relapse was 27,6(± 6,4) months 89,2% and 69,4% of patients reached NEDA-3 at year 2 and year 3 respectively. 5,3% of patients needed a third cycle of therapy. Overall 74,4% of patients had adverse events. Infusion-reaction and infections occurred respectively in 70,1% and 9,8% of patients; regarding secondary autoimmune disease the most frequent was thyroid dysfunction (15,8%).
In our very active MS-population after ALEM-treatment a strong reduction of both relapse rate and MRI activity was achieved. These results strengthen the assumption that aggressive naïve patient is an ideal candidate for immune system resetting, likely due to young age, short disease duration and low disability. Furthermore, absence of previous immunomodulating/immunosuppressant drugs altering the immune system could play a key role in determining effectiveness of this powerful drug. However, longer FU is needed to confirm our data and evaluate whether an early induction therapy could be worthy in this specific population, balancing benefit-risk ratio.