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.
To assess the safety and tolerability of cladribine in MS patients a real-world clinical setting, during treatment follow-up.
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, imaging monitoring and adverse reactions during treatment.
Eighty-five included patients, 54 (63.5%) female, mean age 42±12 years old, mean disease duration 9±7 years. Seventy-seven (90.6%) had relapsing-remitting MS, and the remaining had secondary progressive MS. Median pre-treatment EDSS was 2,0 (1,5-4,0). 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 naïve. 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. Most frequent adverse reactions were lymphocytopenia (43,5%), infections (20,8%) and fatigue (18,1%). After two months of first dose, CD19+ lymphocyte count showed greater reduction compared with CD4+ and CD8+. There were no grade 4 lymphocytopenia cases registered. Four (5.5%) serious adverse reactions were recorded. There were no cases of cladribine withdrawal because of adverse reactions.
This cohort has similar characteristics to the CLARITY trial study population. Registered adverse reactions were comparable to previously described, showing higher incidence of fatigue and lower incidence of infections. This study confirms the short-term tolerability and safety profile of cladribine in real life scenarios.