VANCOUVER, BC—Early administration of subcutaneous interferon (sc IFN) β-1a is associated with better rates of no-evidence-of-disease-activity (NEDA) status than delayed treatment among patients with clinically isolated syndrome (CIS), according to a research-poster presentation at the 68th AAN Annual Meeting. 

“Early treatment with scIFN β-1a was associated with more patients achieving NEDA status, compared with delayed treatment, for up to 5 years,” wrote Patricia K. Coyle, MD, of Stony Brook University, Stony Brook, NY, and coauthors. 

Previous research has shown that early scIFN β-1a treatment (44µg) significantly improves clinical and magnetic resonance imaging (MRI) patient outcomes for up to 5 years, the authors noted. NEDA is a composite clinical and MRI endpoint used to measure disease-modifying treatment efficacy for patients with multiple sclerosis (MS). 

In order to compare NEDA status following early and delayed scIFN β-1a administration, the researchers conducted post-hoc analysis of NEDA status among a total of 517 intent-to-treat patients who had participated in the REFLEX and REFLEXION (REFLEX extensION) studies (NCT00813709).

“NEDA was defined as no relapses, no confirmed disease worsening (no increase in EDSS [Expanded Disability Status Scale] score), and no MRI activity (no new or enlarging T2 or gadolinium-enhancing lesions),” they wrote. 

Patients in the REFLEX trial were randomly assigned after CIS diagnosis to an early-treatment group (scIFN β-1a 44µg three times weekly or once weekly) or placebo, for 24 months. Patients diagnosed with clinically-definite MS (CDMS) were switched to open-label scIFN β-1a 44µg three times weekly. Placebo group patients and patients diagnosed with CDMS in the REFLEXION study, were switched to scIFN β-1a 44µg three times weekly; these patients represented the delayed-treatment study group.

“A dose-dependent, higher proportion of early treatment vs. delayed treatment patients achieved NEDA at each time point,” the authors reported. “At up to 1 year, patients receiving early treatment [three-times-weekly or once-weekly] were more likely to achieve NEDA than those receiving delayed treatment.” 

The odds ratios (OR) for early administration of scIFN β-1a three times weekly vs. delayed treatment was 3.32 (95% CI: 1.93–5.69) and the OR for once-weekly early treatment vs. delayed treatment was 1.95 (95% CI: 1.12–3.40), the authors wrote.

“scIFN β-1a 44µg three times weekly was more likely to lead to NEDA at Years 2, 3 and 5 than delayed treatment,” they reported. “Overall, more patients treated early with scIFN β-1a 44µg three times weekly than those with delayed treatment had radiological activity-free status at 5 years (P=0.001).”

The study was funded by Merck KGaA.