Long-Acting Formulation of Old MS Drug Shows Promise

A long-acting formulation of pegylated interferon beta was found be much more effective than placebo for people with relapsing-remitting multiple sclerosis (MS). The formulation was also superior to placebo for reducing new or active lesions and was effective even though injections were given every 2 weeks instead of every other day.

Researchers from Johns Hopkins University School of Medicine, whose findings were published in Lancet Neurology on May 1, also said fewer patients develop resistance to the long-acting pegylated interferon beta, suggesting more patients could benefit from the new formulation.

The study followed more than 1,500 patients with MS. One-third of patients received a placebo shot every 2 weeks, one-third got 125 micrograms of pegylated interferon beta shots every 2 weeks, and the third group was given 125 micrograms of pegylated interferon beta-1a once a month with a placebo shot given at every other visit.

After 1 year, those taking pegylated interferon beta-1a every 2 weeks had a 36% reduction in yearly relapse rate compared with placebo; the group taking the formulation every 4 weeks had a 28% reduction. MRI showed 67% fewer new or active lesions in the 2-week group, while those injected every 4 weeks had only 28% fewer lesions.

Researchers believe, if approved, the long-acting formulation will improve compliance and tolerability and, therefore, have a positive effect on the quality of life in people with MS who take interferon beta, said study leader Peter A. Calabresi, MD, of Johns Hopkins University School of Medicine.

“The data are very, very clear,” he noted. “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.”

The new version modifies interferon beta by attaching polyethylene glycol (PEG) polymer chemical chains that stabilize the drug. PEG has been proven safe in other medications and personal care products.