Biogen's novel MS drug shows promise of repairing nerve tissue

Biogen's ($BIIB) latest treatment for multiple sclerosis helped repair damaged nerve tissue in a Phase II study, an incremental victory for a novel therapy that has a long way to go.

The treatment, anti-LINGO-1, met its main goal in a study on 82 patients with acute optic neuritis (AON), a disease in which inflammation erodes the layers of protein that protect nerve fibers. Biogen designed the study to measure nerve function by clocking how fast a signal moved from the retina to the brain, with a primary endpoint of improving reaction times compared with placebo. In the study, patients who got at least 5 doses of the antibody demonstrated a 34% improvement on that measure compared at week 24. At 32 weeks, that number jumped to 41%, Biogen said, and both results were statistically significant.

However, anti-LINGO-1 had no effect on the actual thickness of the protein layers, called myelins, and it didn't help improve patients' visual function in the study. Looking at imaging results, Biogen notes that some of the myelins in question had significantly thinned before treatment, meaning the antibody may not have had the chance to prove itself on that measure. And the study's investigators are heralding the results as the first ever demonstration of myelin repair by any metric.

AON has no causal relationship with MS, but both diseases are characterized by the slow destruction of healthy nerve tissue, and Biogen figures any positive results in the former indication have a strong read-through for the latter. Despite the miss on secondary endpoints, the company is counting its Phase II effort, called RENEW, as a net positive for anti-LINGO-1.

"RENEW studied two distinct mechanisms of action--remyelination and neuroprotection," Biogen Chief Medical Officer Alfred Sandrock said in a statement. "We believe that the opportunity to impact neuroprotection was limited by the rapidity with which retinal ganglion cells and their nerve fibers were damaged by the disease. This insight offers valuable information on the speed of axonal loss following an AON attack, and combined with the positive primary endpoint results, will help inform future studies."

Biogen is at work on a separate Phase II trial, called SYNERGY, that is studying the antibody's ability to slow the progression of MS, measuring composite change in cognitive function over 84 weeks. Data from that study are expected in 2016 and will likely make or break the treatment's potential.

- read the statement