Shares of Opexa Therapeutics, Inc.(NASDAQ: OPXA) were up more than 150 percent from Friday’s close in morning trading on Tuesday, after the company announced that more than 83 percent of patients taking its experimental multiple sclerosis drug, Tovaxin, remained relapse-free after one-year.

In addition, the annualized relapse rate among patients who took Tovaxin fell to 20 percent, a 42 percent reduction compared with the placebo. Tovaxin also showed stabilization and improvement of MS-related disabilities in 73 percent of patients, 16.5 percent of which showed sustained improvement of a least one full point on a standard disability scale.

The data was based on a 52-week Phase IIb clinical study that targeted 150 patients with relapsing, remitting multiple sclerosis, typically the initial stage of the disease. Patients in this stage of multiple sclerosis often experience unpredictable relapses, often followed by months or years of dormancy.

“Clinical benefits include not only reduction in relapses, but a surprising reversal of disability in over 16 percent of Tovaxin-treated patients,” said Dawn McGuire, MD, a board certified neurologist and a member of Opexa’s Clinical Advisory Board.

Opexa said it plans to recruit similar patients for another Phase IIb study of Tovaxin, which is a vaccine tailored to individual patients. The drug helps limit attacks by immune system cells called T-cells on myelin, the protein sheath that protects nerves.

Opexa’s news today carried the Stem Cell Stock Index 9.3 percent higher today. The Index, which is compilation of companies using stem cells to develop treatments, is currently ahead of the S&P 500 by 2.7% over the last month.