Long-acting interferon-beta cuts relapse rate in multiple sclerosis

A new long-acting form of interferon-beta has shown significant efficacy versus placebo when used in patients with relapsing–remitting multiple sclerosis (MS), reveal results of a Phase III trial published online in The Lancet Neurology.

In the “ADVANCE” study, pegylated interferon (peginterferon) beta-1a, given every 2 or 4 weeks, was associated with a significantly lower relapse rate after 48 weeks of treatment compared with placebo. Standard interferon-beta is given by injection between one and four times weekly, and its frequent dosing is thought to be a barrier to effective treatment for MS.

“While this isn’t a brand new blockbuster drug, I do think it will improve compliance and tolerability and therefore positively impact the quality of life of people with MS who take interferon beta,” said the study’s lead author Peter Calabresi, a neurologist at Johns Hopkins University, Baltimore, Maryland, USA, in a statement.

He added: “We can make things easier for our patients without dangerous side effects just by tweaking what we know to be a safe, 20-year-old drug.”

ADVANCE was an industry-funded study of 1,512 patients aged 18–65 years with relapsing–remitting MS and an Expanded Disability Status Score of 5 or less. They were randomly assigned to receive subcutaneous peginterferon beta-1a  125 µg every 2 or every 4 weeks or placebo.

The primary endpoint was the relapse rate at week 48. Adjusted annualised relapse rates were 0.256 (confidence interval: 0.206–0.318) with two-weekly and 0.288 (CI: 0.234–0.355) with four-weekly peginterferon versus 0.397 (CI: 0.328–0.481) with placebo.

Hazard ratios confirmed that the risk of relapse after treatment was significantly lower with the study drug relative to placebo. Several secondary endpoints such as the proportion of patients who had 12 weeks of sustained disability progression and the proportion of patients with new or newly enlarging hypertensive lesions on magnetic resonance imaging also favoured active treatment over placebo.

However, the overall incidence of adverse events including relapses was lower in the placebo group (83 per cent) compared with peginterferon (94 per cent with both dosing regimens). Adverse events that were markedly more frequent with peginterferon were injection-site reactions, influenza-like illness, pyrexia and headache.

The study authors admit that longer-term data on the safety and efficacy of the new drug is needed, concluding: “Peginterferon beta-1a, with its less frequent dosing regimen, could address some of the factors that lead to avoidance of treatment or poor adherence, while still providing clinical benefits expected from approved interferon beta therapies.”