Real World Analysis on Lymphocyte Reconstitution After Lymphopenia in Participants Treated by Tecfidera

A Retrospective Analysis in Real World on Lymphocyte Reconstitution After Lymphopenia in Patients Treated by Tecfidera and Description of Management Strategies in France

The primary objective of the study is to describe absolute lymphocyte count (ALC) reconstitution after Dimethyl fumarate (DMF) discontinuation, in Relapsing-Remitting Multiple Sclerosis (RRMS) participants with lymphopenia.

The secondary objectives of the study are characterization of lymphopenia in overall population; characterization of lymphopenia in participant with DMF discontinuation ; description of the evolution of ALC during DMF treatment; description of the time to reach a discontinuation of DMF treatment; exploration of the time to reach clinical outcomes (Expanded Disability Status Scale [EDSS] and relapse) according to lymphopenia; description of the event rate of the serious or opportunistic infections in overall population from DMF initiation and according to DMF discontinuation and lymphopenia; description of the event rate of serious and opportunistic infections in overall population from DMF initiation and according to lymphopenia; estimation of the associations between the baseline demographic and clinical characteristics and the risk to reach a lymphopenia; estimation of the associations between the baseline demographics and clinical characteristics and the risk to reach an ALC reconstitution after DMF discontinuation in participants with lymphopenia; and investigation of the changes of absolute cluster of differentiation 4 (CD4) and cluster of differentiation 8 (CD8) count in overall population on DMF if available.

The study will select participants initiating treatment from 01 Jan 2016 to 15 Dec 2020.

Inclusion Criteria:

• Clinical diagnosis of RRMS at DMF initiation

• Minimum of 3 months of continuous treatment with DMF*

• Initiation of DMF between January 1st, 2016 and December 15th, 2020

• Minimum of 2 ALC assessments:

  1. 1 ALC at DMF initiation (or within 6 months before DMF initiation); or under DMF treatment

  2. 1 ALC before the database extraction (15/06/2021).

     • to avoid the early DMF discontinuations for reasons other than lymphopenia.

Exclusion Criteria:

• Participants will be excluded from the study entry if they express their opposition to collect the data upon the information.