Assessing the impact of persistency for disease-modifying therapies in a German registry for multiple sclerosis

Aim: To identify, characterize, and compare outcomes of patients with high persistency (HP) and low persistency (LP). Methods: Study data came from MS disease registry of the doctors-run German NeuroTransData(NTD) network of neurologists and psychiatrists capturing demographic, clinical history, and clinical variables during outpatient visits. Inclusion criteria were patients with RRMS, treatment naïve or 1 switch, and with one future visit after therapy start. Only patients with an index date (i.e., therapy start) after 1 January 2009 were retained.From patient distribution, HP was defined as continuous exposure time of at least two years, while LP was less than two years. Propensity Score Matching was performed on age, sex, relapses, baseline EDSS, and time since MS manifestation for 1 year pre-index. Cox regression was used to compare time to first relapse and time to 12-week confirmed disability progression (CDP). Results: In total, 2,367 patients were matched for HP and LP cohorts. The mean [standard deviation (SD), interquartile range (IQR)] for age was 38.3 (10.7; 29.9-46.4) years, 0.7 relapses in the past year (0.8; 0-1), mean baseline EDSS was 2.0 (1.5;1-3), and symptoms manifestation time was 6.6 years (sd:7.2; 0.96-10.3); 76.2% were females. Mean (SD; IQR) DMT exposure time in years was 0.78 years (0.57;0.29-1.2) for the LP cohort and 4.7 (2.2;2.9-6.2) for the HP cohort.The use of DMTs was: 49.1% on injectables, 40.5% on orals, 2.2% on infusions (excluding monoclonal antibodies) and 8.2% on monoclonal antibodies. Using Cox Regression, the hazard ratio (95% CI) on time to relapse for LP versus HP cohort was 1.4 (1.3-1.5) (Wald p value: < 0.001). For time to first CDP, it was 1.2 (1.0-1.3) (Wald p value: 0.011). Conclusion: HP had better outcomes on time to first relapse than matched LP cohort. The minor difference in CDP risk between two cohorts may be due to 2 years limited follow-up. These findings support the importance of identifying appropriate DMTs for individual patients with due consideration to their underlying disease characteristics in maintaining treatment persistency and improved outcomes