Health economic outcomes of switching to alemtuzumab from other disease-modifying therapies in people with multiple sclerosis in the USA.

Aim: Describe demographics, clinical characteristics, healthcare resource utilization (HCRU) and costs in people with multiple sclerosis (pwMS) switching to alemtuzumab from other disease-modifying therapies (DMTs). Patients &

Methods: Retrospective, observational study of IBM®MarketScan® claims database. PwMS previously treated with DMTs and initiating alemtuzumab (1 January 2013 to 31 December 2019) were identified. "Index" was date of alemtuzumab initiation (prescription filled).

Results: The study cohort (n = 341) was primarily female (72%) with (mean ± standard deviation) age 45.1 ± 9.5 years. At index, duration of MS was 5.3 ± 2.8 years. HCRU (inpatient/outpatient services), outpatient costs (including MS-specific MRI and emergency room visits) and annualized relapse rate significantly reduced over the 2 years following initiation of alemtuzumab. DMT costs reduced over the same period.

Conclusion: Health economic and clinical benefits were seen following switching to alemtuzumab from other DMTs for treatment of MS, in this cohort from the USA.