* Says 83 pct of patients relapse free after a year
* Shares more than triple to $5.66 (Updates share price, volume, adds top shareholders)
NEW YORK, Sept 8 (Reuters) - Opexa Therapeutics Inc OPXA.O said on Tuesday further analysis of clinical data showed that more than 83 percent of patients taking its experimental multiple sclerosis drug remained relapse-free after a year.
The news more than tripled the value of the tiny company in extremely heavy trading. Opexa shares closed up $4.13 at $5.66 on Nasdaq with more than 56 million shares traded, meaning every share in the company has traded nearly five times.
The biotechnology company said the favorable data were seen in a mid-stage study of 150 patients with relapsing remitting multiple sclerosis. Patients with this type of MS -- typically the initial stage of the progressive neurological disease -- have unpredictable relapses followed by months to years of no new signs of disease activity.
The company said the annualized relapse rate among patients who took its Tovaxin drug fell to 20 percent, a 42 percent reduction compared with placebo.
Moreover, the company said 73 percent of Tovaxin-treated patients showed stabilization or improvement in MS disability, including 16.5 percent with a sustained improvement of at least one full point on a standard disability scale.
Opexa, based in The Woodlands, Texas, said it plans to recruit similar patients for another Phase IIb study of the drug, which is a vaccine tailored to individual patients. It helps limit attacks by immune system cells called T-cells on myelin, the protein sheath that protects nerves.
The company’s top shareholders include the Albert and Margaret Alkek Foundation, which held more than 12 percent of outstanding shares, according to Reuters Estimates, and several company board members and officers, including Medivation IncMDVN.O chief executive David Hung. (Reporting by Ransdell Pierson and Bill Berkrot, editing by Dave Zimmerman, Gerald E. McCormick, Leslie Gevirtz)