Safety and effectiveness of cladribine in multiple sclerosis - clinical experience of five tertiary centers

Background: Cladribine is a selective and oral immunological reconstitution treatment, approved in Europe in 2017 and in Portugal in 2018 for very active multiple sclerosis (MS) with relapses Its safety and efficacy profile were assessed in phase III CLARITY (2005-2009) trial Post-commercialization studies in real life conditions, are essential to confirm this profile Objectives: To assess the efectiveness of cladribine in multiple sclerosis patients a real-world clinical setting, during treatment follow-up Methods: Observational, multicentric, prospective study Consecutive MS patients treated with cladribine were included in two tertiary hospitals in Lisbon and followed during treatment Demographic and clinical aspects, EDSS, previous disease-modifying drugs (DMD) and annual relapse rate (ARR) were recorded, as well as laboratory and imaging monitoring during treatment Results: Eighty-five included patients, 54 (63 5%) female, mean age 42±12 years old, mean disease duration 9±7 years Seventyseven (90 6%) had relapsing-remitting MS, and the remaining had secondary progressive MS Median pre-treatment EDSS was 2,0 (1,5-4,0), and 40 (47 1%) patients had at least one relapse in previous year Most (65 9%) patients had been submitted to more than one DMD before, 43 (51 2%) with first-line therapies and 9 (10 7%) were naive Cladribine was started in 57 (68 7%) patients due to inefficacy of previous drug Mean follow-up time was 13±6 months, and 54 (63 5%) completed first year of treatment Second year of treatment was delayed in some patients due to global COVID-19 pandemic Fifteen relapses were registered in 12 patients Five (5 9%) stopped treatment because of disease activity in the first year After 12 months of follow-up (n=54), no difference was found between previous and 12-month EDSS medians (2 (IQR 1,5-4,0) vs 2 (IQR 1,25-4) p=0 606) Mean 12-month ARR (0,1±0,4) was significantly inferior to previous year ARR (0,6±1,0), p\u003c0 001 Conclusions: At pivot trial, the efficacy of cladribine was proved after two annual treatment cycles In this population, short follow-up period is a limitation, but after mean follow-up of one year, clinical estabilization was found in MS patients treated with cladribine