Annexon's neurological disease drug succeeds in late-stage study

By Sneha S K

(Reuters) -Annexon said on Tuesday a late-stage study showed its experimental drug helped improve motor functions in patients with Guillain-Barre syndrome, a neurological disease in which the body's immune system attacks the nerves and can cause paralysis and even death.

Shares of the company rose 29% to $5.93. The drug, ANX005, was tested in 241 patients with GBS and met the main goal of the study.

The study was conducted in Bangladesh and the Philippines due to the high prevalence of the disease and limited access to standard of care treatment in both the countries, the drug developer said. Annexon has begun another trial to confirm the results in U.S. patients.

A single infusion of the drug achieved a statistically significant 2.4-fold improvement, compared to the placebo, on a disability scale that measures motor functions, such as walking, at eight weeks, Annexon said.

The drug also showed improvements versus placebo on secondary goals of the trial, including early gains in muscle strength and fewer days on artificial ventilation.

An estimated 3,000 to 6,000 people develop GBS in the United States. While most fully recover, some have permanent nerve damage.

Currently, there are no approved treatments for GBS by the U.S. Food and Drug Administration.

The current standard of care for the disease is intravenous infusion of immunoglobulin, a treatment that helps increase antibody levels.

Annexon's drug appears "be at least as equivalent to existing therapies and possibly better," said Hugh Willison, professor emeritus of neurology at the University of Glasgow, while noting that details on the trial were scarce.

If approved, the company plans to supply the drug through a manufacturing partnership with Swiss pharmaceutical supplier Lonza.

(Reporting by Sneha S K; Editing by Shilpi Majumdar and Krishna Chandra Eluri)