Predicting long-term sustained disability progression in multiple sclerosis: application in the CLARITY trial (4063)

Objective: To externally validate the previously developed sustained progression score which established 6-month confirmed disability progression events as indicators of long-term disability worsening in randomized double-blind CLARITY (Cladribine Tablets Treating MS Orally) trials. Background: Prevention of disability over the long-term is the main treatment goal in multiple sclerosis (MS), however, randomized clinical trials provide only short-term (3–6-month) treatment effect on disability. Design/Methods: Data from the CLARITY and CLARITY 2-year Extension study were used. The 3-and 6-month confirmed disability progression events and the time over which progression remained sustained were identified. Clinico-demographic characteristics of patients at the time of progression previously associated with the likelihood of improvement after confirmed progression event were used to calculate the sustained progression score for each progression event. A Cox proportional hazards model was used to validate the association of the score calculated for each 6-month confirmed disability progression event with time to improvement. To demonstrate application of the score in trial setting, effect of cladribine on 3-month confirmed progression events with any score and score>1.5 was evaluated. Results: A total of 667 6-month confirmed disability progression events were identified in the combined dataset, of which only 12 were followed by a 6-month confirmed disability improvement. The external validation of the score illustrated a trend towards a decrease in the likelihood of disability improvement in progression events with higher score (Hazard Ratio HR=0.72, 95% CI: 0.21–2.42). Results confirmed that oral cladribine reduced the risk of disability progression that was likely to be sustained over the long-term (only events with score>1.5; HR: 0.64; 95% CI: 0.47–0.87). Conclusions: The sustained progression score, estimated using the characteristics of confirmed progression events, provides important complementary information that will allow future trials to establish the effect of therapy not only on short-term but also on long-term disability accrual. Disclosure: Dr. Sharmin has nothing to disclose. Francesca Bovis has nothing to disclose. Maria Pia Sormani has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Biogen. Maria Pia Sormani has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Roche. Maria Pia Sormani has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Sanofi. Maria Pia Sormani has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Merck. Maria Pia Sormani has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Celgene. Maria Pia Sormani has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Novartis. Maria Pia Sormani has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Geneuro. Maria Pia Sormani has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Medday. Maria Pia Sormani has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Sanofi. Maria Pia Sormani has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Roche. Dr. Butzkueven has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Oxford Health Policy Forum. The institution of Dr. Butzkueven has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for Biogen. The institution of Dr. Butzkueven has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for Merck. The institution of Dr. Butzkueven has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Novartis. The institution of Dr. Butzkueven has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Roche. Dr. Butzkueven has received personal compensation in the range of $10,000-$49,999 for serving as an officer or member of the Board of Directors for MSBase . The institution of Dr. Butzkueven has received research support from NHMRC. The institution of Dr. Butzkueven has received research support from Biogen. The institution of Dr. Butzkueven has received research support from Roche. The institution of Dr. Butzkueven has received research support from Novartis. Tomas Kalincik has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Roche. Tomas Kalincik has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Sanofi Genzyme. Tomas Kalincik has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Novartis. Tomas Kalincik has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Merck. Tomas Kalincik has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Biogen. Tomas Kalincik has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Biogen. Tomas Kalincik has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Roche. Tomas Kalincik has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Sanofi Genzyme. Tomas Kalincik has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Novartis. Tomas Kalincik has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Merck. Tomas Kalincik has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for WebMD Global. Tomas Kalincik has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for Novartis. Tomas Kalincik has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for Biogen. Tomas Kalincik has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for Sanofi Genzyme. Tomas Kalincik has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for Teva. Tomas Kalincik has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for BioCSL. Tomas Kalincik has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for Merck. The institution of Tomas Kalincik has received research support from Biogen. The institution of Tomas Kalincik has received research support from Novartis. The institution of Tomas Kalincik has received research support from Genzyme. The institution of Tomas Kalincik has received research support from Roche. The institution of Tomas Kalincik has received research support from Celgene. The institution of Tomas Kalincik has received research support from Merck. The institution of Tomas Kalincik has received research support from MSBase Foundation. The institution of Tomas Kalincik has received research support from ARSEP and EDMUS Foundations. The institution of Tomas Kalincik has received research support from MS Research Australia. The institution of Tomas Kalincik has received research support from National Health and Medical Research Council. The institution of Tomas Kalincik has received research support from Australian Research Council. The institution of Tomas Kalincik has received research support from MS Society.