Summary of Research: Cognition and Employment Status of People with Relapsing Multiple Sclerosis Treated with Cladribine Tablets: Two-Year CLARIFY-MS Study

Brochet B(1), Langdon D(2), Havrdova EK(3), Lechner-Scott J(4)(5), Montalban X(6), Patti F(7), Solari A(8), Alexandri N(9), Lehn A(9), Smyk A(9), Selmaj K(10)(11); CLARIFY-MS Investigators.

Author information:
(1)INSERM U 1215, University of Bordeaux, Bordeaux, France.
.
(2)Department of Psychology, Royal Holloway, University of London, Egham,
Surrey, UK.
(3)First Medical Faculty, Department of Neurology and Center for Clinical
Neuroscience, Charles University, Prague, Czech Republic.
(4)University of Newcastle, Newcastle, NSW, Australia.
(5)Division of Neurology, John Hunter Hospital, Newcastle, NSW, Australia.
(6)Department of Neurology-Neuroimmunology Centre of Multiple Sclerosis of
Catalonia (Cemcat), University Hospital Vall d’ Hebron, Barcelona, Spain.
(7)Department of Medical and Surgical Sciences and Advanced Technologies, GF
Ingrassia, and Azienda Ospedaliero Universitaria Policlinico « G Rodolico »- San
Marco, University of Catania, Catania, Italy.
(8)Unit of Neuroepidemiology, Fondazione IRCCS Istituto Neurologico Carlo Besta,
Milan, Italy.
(9)Merck Healthcare KGaA, Darmstadt, Germany.
(10)Center for Neurology, Lodz, Poland.
(11)Department of Neurology, University of Warmia and Mazury, Olsztyn, Poland.

INTRODUCTION: Cognitive impairment is a common issue for people with multiple
sclerosis (MS), affecting their daily lives and work. This study aimed to report
the cognition and employment status of participants with highly active relapsing
MS (RMS) treated with cladribine tablets (CladT) during the 2-year, open-label,
single-arm, Phase 4 CLARIFY-MS study.
METHODS: In this post hoc analyses, 482 participants with highly active RMS
received at least one dose of CladT. Cognitive function was assessed using the
Brief International Cognitive Assessment for MS (BICAMS) at the start of the
study (baseline [BL]), and at 12 and 24 months (M) after initiating treatment
with CladT (n = 399). Symbol Digit Modalities Test (SDMT) scores were further
analysed to check for clinically meaningful changes (4- and 8-point) from BL to
M24. Employment status was also evaluated.
RESULTS: Cognitive function: BICAMS parameter scores remained stable over 24
months. Most participants showed stable or improved cognitive processing speed,
as measured by clinically meaningful 4- and 8-point changes in the SDMT scores
from BL to M24. Employment status: No major differences in the employment
status of participants were observed over 2 years, with > 40% of participants
being in full-time employment during the study.
CONCLUSIONS: Most CLARIFY-MS participants with highly active RMS treated with
CladT showed clinically meaningful improvements and stability in SDMT scores at
M24 compared to BL, with overall cognitive function (BICAMS scores) remaining
stable over 2 years. Despite the challenges posed by the COVID-19 pandemic, most
participants maintained stable employment over 24 months, supporting the
positive quality-of-life outcomes associated with CladT and supporting its
overall efficacy in treating RMS.

© 2026. The Author(s).

DOI: 10.1007/s40120-026-00952-w
PMID: 42271112

Conflict of interest statement: Declarations. Conflict of Interest: Please see
the original article for full author disclosures. Ethical Approval: The
CLARIFY-MS study was conducted in accordance with the principles outlined in the
Declaration of Helsinki and the International Council for Harmonisation
Guidelines for Good Clinical Practice. This study was approved by independent
ethics committees or institutional review boards at each study site.
Participants provided written informed consent prior to the initiation of any
study-related activities. Details of all institutional review boards and ethics
committees are available in Supplementary Table S5 of the original publication.

Auteurs Bordeaux Neurocampus