Comparative treatment effectiveness of oral fingolimod and conventional injectable disease modifying agents in multiple sclerosis.

BACKGROUND Fingolimod was the first approved oral Disease Modifying Agent (DMA) to reduce relapses in Multiple Sclerosis (MS). Previous observational studies assessed the effectiveness of DMAs only through relapse and did not consider the treatment switch. OBJECTIVE To compare the effectiveness of oral fingolimod and conventional injectable DMAs using the composite endpoint of relapse or treatment switch in patients with MS. METHODS This retrospective longitudinal study utilized the IBM MarketScan Commercial Claims and Encounters Database from 2010-2012. Adults (≥18 years) with MS diagnosis (ICD-9-CM:340) and newly initiated with a DMA were included. Cox Proportional Hazards (PH) regression model weighted for stabilized Inverse Probability Treatment Weights (IPTW) with robust sandwich estimator was used to evaluate the composite endpoint (time to relapse/treatment switch) between oral fingolimod and injectable DMA users during the one-year follow-up after the treatment initiation. Additional analyses were performed on patients who were adherent (proportion of days covered [PDC]≥0.8) to DMAs during the first three months. RESULTS The incident study cohort consisted of 1,997 MS patients who initiated oral fingolimod (15.6%) or injectable (84.4%) DMAs. The proportion of patients who had a composite endpoint (relapse/DMA treatment switch) in oral fingolimod and injectable DMA users was found to be 16.72% and 27.16%, respectively. The Cox PH regression model with stabilized IPTW revealed that fingolimod is equally effective as injectable DMAs in reducing the risk of experiencing the composite endpoint of relapse or DMA switch (adjusted Hazards Ratio [aHR]: 0.67, 95% CI: 0.43-1.03). Additional analysis among patients who were adherent also found no significant difference in the composite endpoint (aHR: 0.70, 95% CI 0.49-1.15) between oral fingolimod and injectable DMA users. CONCLUSIONS Oral fingolimod has similar effectiveness as injectable DMAs in reducing the risk of experiencing the composite endpoint (relapse or treatment switch). In addition, when assessed independently, oral fingolimod showed no difference in reducing the time to relapse or DMA treatment switch compared to injectable DMA users.