To Örebro University

Background: Cladribine  is  a  deoxyadenosine  analogue  prodrug  that selectively  induces  immune  reconstitution  by  targeting  B-  and  T-lymphocytes. Cladribine  tablets  (CladT)  are  administered  in two courses, 12 months apart, for patients with relapsing multiple sclerosis (RMS). Post-marketing surveillance is important for evaluation  of  long-term  safety  and  effectiveness  in  a  real-world setting. CLADCOMS (CLADribine tablets long-term Control Of MS) is a post-marketing investigator driven study. Here we report one year follow-up data on the first 100 patients included in the study in April 2021.

Objective: 1) To  investigate for how long a full dose treatment with Cladribine 10 mg tablets (3.5 mg/kg over two years) offers freedom of disease activity in relapsing MS patients.2) To collect complete data on safety and effectiveness with the help of the Swedish Neuroregistry to enable future assessment on effectiveness and safety in comparison with other in Sweden commonly used disease modifying treatments.

Methods: CLADCOMS  includes  patients  with  relapsing  MS  from  the  eight academic  clinics  starting  Cladribine  treatment  after  23rd  of  March  2018. Data  is  collected  in  the  Swedish  Neuroregistry  using  highly  structured  yearly follow-up  routines.   Descriptive   data   on   relapses,   MRI   activity,   Patient   Reported   Outcome   Measures   and   Serious   Adverse   events   (SAEs)  from the  first  100  patient  included  in  the  study  are  obtained from the registry.

Results: Up  to  April  2022  1XX  patients  were  included  in  the  study. In April 2021 the first 100 patient entered the study. 40% of patients included were treatment naïve, 29% switched from natalizumab and 13% from rituximab. By April 2022, 5 patients experienced a relapse during the treatment initiation and showed MRT activity with contrast enhancing (CEL)lesions more than six months after initiation of treatment, of which 2 patients showed CEL more than six months after the second treatment course year two. 20% of the patients showed new lesions on the first MRI performed up to 18 months after treatment initiation. Two patients reported SEAs. Analysis of CD19   and   CD27-   B-cells   counts   over   time   will   be   performed.

Conclusions: Cladribine treatment demonstrates clinical stability in patients treated ⩾ 12 months. However, continued follow-up is needed to assess the effectiveness and safety of treatment with Cladribine over a longer time to investigate time to disease reactivation after the second treatment course year two has been administered.