VANCOUVER, BC—Switching to natalizumab from other disease-modifying therapies (DMTs) is associated with reduced relapse rates among patients with relapsing-remitting multiple sclerosis (RRMS), according to authors of a safety and efficacy analysis presented as a research poster at the 68th Annual AAN Meeting.
“Regardless of prior DMT usage, natalizumab reduced MS disease activity and showed a favorable benefit risk profile that is consistent with previous assessments,” wrote lead study author Helmut Butzkueven, MD, of the University of Melbourne in Australia, and coauthors.
The researchers analyzed patients who had switched from interferon beta/glatiramer acetate (BRACE) to natalizumab (n=4,688), from fingolimod to natalizumab (n=162), or who started first-line natalizumab (n=552). Annualized relapse rates before and after switch to natalizumab were 1.99 vs. 0.22 for patients switching from BRACE; 2.05 vs. 0.35 for fingolimod; and 2.06 vs. 0.16 for DMT-naïve patients (first-line natalizumab patients; P values for pre- and post-switch values all three groups <0.001).
The results are part of the ongoing international open-label observational TOP trial.
The authors reported no new safety concerns for natalizumab. One-year and two-year cumulative natalizumab-discontinuation probabilities were 15.3% and 29.3% for patients switching from fingolimod, 9.1% and 20.6% for BRACE switchers, and 9.7% and 21.1% for treatment-naïve (first-line natalizumab) patients, the coauthors reported.
The leading cause of discontinuation in all groups was concern about progressive multifocal leukoencephalopathy (PML) risk.
Serious adverse event (SAE) incidences were low, affecting 11% of BRACE switchers, 4.9% of fingolimod switchers, and 10% of first-line natalizumab patients.
Dr. Butzkueven disclosed receiving board-member compensation from Biogen. All of the study authors are past or present employees of Biogen, or have received support from Biogen.