September 22, 2008

Opexa Reports Top-Line Data From Phase IIb Multiple Sclerosis Study

Opexa Therapeutics has announced top-line data from the company's Phase IIb Tovaxin for early relapsing multiple sclerosis, or Terms, study. Top-line results from the study demonstrated a positive trend in the reduction in annualized relapse rate for patients treated with Tovaxin as compared to placebo.

However, this finding did not achieve statistical significance. In addition, the study did not achieve statistical significance with its primary endpoint, the cumulative number of gadolinium-enhanced brain lesions.

Top-line results from the study showed that Tovaxin-treated patients experienced an annualized relapse rate (ARR) of 0.214 as compared to 0.339 for placebo-treated patients. Despite the low relapse rate in the placebo arm, this still represented a 37% decrease in ARR for Tovaxin as compared to placebo in the general population. Additionally, in the group of patients who had an ARR>1 at study entry, Tovaxin demonstrated a 55% reduction in ARR as compared to placebo.

The study also demonstrated that Tovaxin was safe and well tolerated with no serious adverse events related to treatment. Opexa believes that this favorable safety profile may be an important advantage as patient compliance represents a significant challenge due to serious side effects associated with many currently available multiple sclerosis (MS) treatments.

The initial review of data revealed that patients in the study's Tovaxin arm, on average had a substantially greater number of MRI brain lesions and corresponding lesion volumes at baseline compared to the average number of MRI brain lesions and lesion volumes per patient in the placebo group. The company believes that this unexpected imbalance may have contributed to the study not achieving its primary and secondary endpoints as patients in the Tovaxin arm began the study with greater disease burden and increased severity of disease.

Neil Warma, president and CEO of Opexa, said: "The annualized relapse rate of 0.214 seen in the Tovaxin treatment arm is on par with the lowest relapse rates observed with currently available MS treatments which range from 0.2 to 0.9. This rate is also consistent with ARRs that we have seen in the Tovaxin treatment arms in each of the three previously conducted Tovaxin clinical studies.

"Findings further showed Tovaxin to possess an impressive safety profile with no serious adverse events related to treatment. This level of safety and tolerability addresses a critical unmet need for MS patients. We believe that these positive ARR results combined with an excellent safety profile and convenient dosing place Tovaxin in a very favorable position for continued development as an innovative MS therapy."

Opexa intends to complete a comprehensive analysis of all data from the Terms study over the next several months.