title: Cladribine tablets for relapsing-remitting multiple sclerosis: Efficacy across patient subgroups from the phase III CLARITY study.
abstract: BACKGROUND
  In the phase III CLARITY study, treatment with cladribine tablets at cumulative doses of 3.5 or 5.25mg/kg over 96 weeks led to significant reductions in annualized relapse rates (ARR) versus placebo in patients with relapsing-remitting multiple sclerosis. Further post hoc analyses of CLARITY study data were conducted to determine the efficacy of cladribine tablets across patient subgroups stratified by baseline characteristics.
  
  
  METHODS
  Relapse rates over the 96-week CLARITY study were analyzed in cohorts stratified by demographics; disease duration; treatment history and disease activity at baseline.
  
  
  RESULTS
  In the intent-to-treat population (n=437, 433 and 456 in the placebo, cladribine 3.5 and 5.25mg/kg groups, respectively), treatment with cladribine tablets 3.5 and 5.25mg/kg led to consistent improvements in ARR versus placebo in patients stratified by gender; age (≤40/>40 years); disease duration (<3/3-10/>10 years); prior disease-modifying drug treatment (treated/naïve); relapses in the prior year (≤1/2/≥3); Expanded Disability Status Scale score (<3.5/≥3.5); T1 gadolinium-enhancing lesions (presence, absence); and T2 lesion volume (≤median/>median) at baseline (all P≤0.05 for reduction in the relative risk of relapse [cladribine tablets versus placebo]). Significant effects were also observed in patients who had only one relapse in the year prior to study entry (n=306, 303 and 323 in the placebo, cladribine 3.5 and 5.25mg/kg groups, respectively) and who were further stratified according to other measures of disease activity at baseline.
  
  
  CONCLUSIONS
  Treatment with cladribine tablets provides consistent reductions in ARR compared with placebo across the spectrum of baseline demographics and disease characteristics represented in the CLARITY study.
authors: Multiple Sclerosis Center, Department of Neurology, Clinical Research Building, 1120 NW 14th Street, 13th Floor, Miami, FL 33136, USA. Electronic address: KRammohan@med.miami.edu.
authors: Kottil
authors: K
authors: Rammohan
authors: Queen Mary University London, Blizard Institute of Cell and Molecular Science, Barts and The London School of Medicine and Dentistry, 4 Newark Street, Whitechapel, London E1 2AT, UK. Electronic address: g.giovannoni@qmul.ac.uk.
authors: Gavin
authors: G
authors: Giovannoni
authors: Department of Neurology and Institute of Experimental Neurology Università Vita-Salute San Raffaele, Via Olgettina 48, 20132 Milan, Italy. Electronic address: comi.giancarlo@hsr.it.
authors: Giancarlo
authors: G
authors: Comi
authors: University of Medicine and Dentistry, New Jersey Medical School, 65 Bergen Street, Newark, NJ 07101, USA. Electronic address: cooksd@umdnj.edu.
authors: Stuart
authors: S
authors: Cook
authors: Bamberg Academic Hospital, University of Erlangen, Buger Strasse 80, D-96049 Bamberg, Germany. Electronic address: peter.rieckmann@sozialstiftung-bamberg.de.
authors: Peter
authors: P
authors: Rieckmann
authors: Copenhagen University Hospital, Rigshospitalet, 9, Blegdamsvej, DK-2100 Copenhagen, Denmark. Electronic address: pss@rh.dk.
authors: Per
authors: P
authors: Soelberg Sørensen
authors: University of Lille-Nord de France, Pole de Neurolgie, Hopital R Salergro, CHU de Lille 59037, Lille, France. Electronic address: PVERMERSCH@CHRU-LILLE.FR.
authors: Patrick
authors: P
authors: Vermersch
authors: Merck Serono SA-Geneva, 9 Chemin de Mines,1202 Geneva, Switzerland. Electronic address: anthony.hamlett@emdserono.com.
authors: Anthony
authors: A
authors: Hamlett
authors: Merck Serono SA-Geneva, 9 Chemin de Mines,1202 Geneva, Switzerland. Electronic address: nuwan.kurukulasuriya@emdserono.com.
authors: Nuwan
authors: N
authors: Kurukulasuriya
keywords: Administration; Cladribine; Disease-modifying drug; Oral; Relapsing-remitting multiple sclerosis; Treatment outcome