Decreased Relapse Activity for those who Switch to Natalizumab from Alternative Disease Modifying Therapies: An Observational Study (P3.272)

OBJECTIVE: To examine the impact of switching from disease modifying therapies (DMTs), such as interferons or glatiramer acetate (GA), to persistent natalizumab use on claims-based relapse rates. Secondary objectives examined the impact of switching from persistent natalizumab use to other DMTs on claims-based relapse rates. BACKGROUND: Natalizumab for relapsing-remitting multiple sclerosis (MS) has shown to be effective in reducing relapse activity after switching from other DMTs. DESIGN/METHODS: Using the IMS PharMetrics Plus claims database (years 2006-2012), we identified MS subjects who initiated natalizumab (no natalizumab claims in year prior) and had at least two years of follow-up. Persistence in annual follow-up periods was defined as no 90 day or greater gap in natalizumab therapy. Relapse was an MS-related hospitalization or outpatient visit with intravenous or oral steroid burst claim within 7 days. Analyses compared patient observations (i.e., within subject) based on changes in natalizumab persistence and switching status from one year to the next (e.g. transitioning from GA to persistent on natalizumab), and estimated differences in annualized relapse rates. RESULTS: A total of 107 patient observations switched DMTs in the year prior; 25 (23[percnt]) of these transitioned to persistence on natalizumab. 2,723 patient observations were persistent on natalizumab in the year prior; 267 (10[percnt]) of these switched to another DMT. Patient observations switching from alternative DMTs and transitioning to persistent natalizumab use were associated with a relapse-rate decrease of -0.44 (95[percnt] CI: -0.76, -0.13). Patient observations transitioning from persistent on natalizumab to alternative DMTs were associated with a relapse-rate increase of 0.34 (95[percnt] CI: 0.17, 0.52). CONCLUSIONS: Findings suggest those who transition from other DMTs to persistent on natalizumab have statistically significant reductions in annual relapse rates. Alternatively, real-world persistent natalizumab users who switch to another DMT have statistically significant increases in annual relapse rates. Study Supported by: Biogen Idec. Disclosure: Dr. McQueen has received personal compensation for activities with Health Economics Consulting Group LLC. Dr. Livingstone has received personal compensation for activities with Biogen Idec as an employee. Dr. Vollmer has received personal compensation for activities with Acorda Therapeutics, Biogen Idec, Genentech, Inc., Novartis, Ono Pharmaceutical, Teva Neuroscience, and XenoPort as a consultant. Dr. Corboy has received personal compensation for activities with ProCE, Celgene, Teva, Novartis, and Biogen Idec. Dr. Nair has received compensation from Janssen Pharmaceuticals and Biogen Idec as a consultant. Dr. Campbell has received personal compensation for activities with PEcon LLC as a consultant.