1Alessandra Solari, 2Xavier Montalban, 3,4Jeannette Lechner-Scott, 5Fredrik Piehl, 6Bruno Brochet, 7Dawn Langdon, 8Raymond Hupperts, 9Krzysztof Selmaj, 10Eva K. Havrdova, 11Francesco Patti, 12Luis Brieva, 13Eva Maria Maida, 14Nektaria Alexandri, 14Paul Kamudoni, 14Axel Nolting, 14Birgit Keller

1Unit of Neuroepidemiology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy; 2Department of Neurology-Neuroimmunology Centre of Multiple Sclerosis of Catalonia (Cemcat), University Hospital Vall d’Hebron, Barcelona, Spain; 3University of Newcastle, Newcastle, NSW, Australia; 4Division of Neurology, John Hunter Hospital, Newcastle, NSW, Australia; 5Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; 6INSERM U 1215, University of Bordeaux, Bordeaux, France; 7Department of Psychology, Royal Holloway, University of London, Egham, UK; 8Zuyderland Medisch Centrum Sittard, Maastricht University Medical Center, Maastricht, The Netherlands; 9Center for Neurology, Lodz, Poland; 10Charles University, First Medical Faculty, Prague, Czech Republic; 11Department of Medical and Surgical Sciences and Advanced Technologies, GF Ingrassia, University of Catania, and Azienda Ospedaliero Universitaria Policlinico “G Rodolico”- San Marco, University of Catania, Italy; 12IRBLLEIDA, Hospital Arnau de Vilanova, Lérida, Spain; 13Multiple Sclerosis Center, Vienna, Austria; 14Merck Healthcare KGaA, Darmstadt, Germany


Multiple Sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system affecting young adults. It is considered one of the major causes of disability in adults. The prevalence of MS is increasing globally. In Saudi Arabia (KSA) it is reported that the projected overall prevalence of MS is 40/100,000 for the total population and higher for Saudi nationals at 61.95/100,000 putting Saudi Arabia above the low-risk zone as per Kurtzke classification (1). With this rising prevalence, and the established significance of multidisciplinary team management, there is a growing need for specialist MS nurses. A group of specialized MS nurses formed an advisory group to support the role of the MS nurse in the management of patients with MS in KSA. This is the first advisory board meeting aiming to optimize nursing care for MS patients in KSA.

Design and Method(s):

In CLARIFY-MS (NCT03369665), patients with highly active relapsing MS were assigned to receive CladT 3.5 mg/kg cumulative dose over 2 years. Patients were recruited as per the EU label. Results in this interim analysis, conducted prior to the second year of treatment, were assessed using a mixed-effects linear model. Analyses were also conducted for cohorts separated by treatment naïve/prior disease-modifying therapy (DMT), and MSQoL reporting performed before/after the start of the COVID-19 pandemic, as defined as the first reported fatality within each country.


Of the 482 patients treated with CladT, 70.1% were female and the mean age was 37.4 years. Of the 426 patients who provided MSQoL-54 data, statistically significant (p<0.0001) improvements from Baseline to Month 12 were observed for physical and mental health composite scores with estimated changes of 4.51 (95% confidence interval [CI] 3.24–5.77) and 4.53 (95% CI 3.00–6.05), respectively. Similar trends were apparent for treatment naïve (n=121) and prior DMT (n=305) cohorts. There was no indication that the start of the COVID-19 pandemic had an impact on MSQoL-54 reporting. Regarding safety, 322 patients (66.8%) experienced at least one treatment-emergent adverse event, most commonly headache (16%), nasopharyngitis (9%), and lymphopenia (9%). The majority of observed post-baseline lymphopenia events were grade 1–2; fewer patients reported grade 3 lymphopenia, no grade 4 lymphopenia was observed.


With only half a therapeutic dose of CladT, this interim analysis demonstrates a statistically significant improvement in the physical and mental health composite scores of MSQoL-54 at 1 year. No new safety concerns were found in this 1-year interim analysis, with no new severe or opportunistic infections that could have an impact on the established benefit:risk profile of CladT in MS.