Opexa Provides Additional Promising Data Including Statistically Significant Reduction in Disability With Tovaxin® for the Treatment of Multiple Scle

Tovaxin Also Demonstrates Reduction in Relapse Risk and Myelin T-cell Reactivity in Patients With More Active Disease

THE WOODLANDS, Texas--(BUSINESS WIRE)--Opexa Therapeutics, Inc. (NASDAQ:OPXA), a company dedicated to the development of patient-specific cellular therapies for the treatment of autoimmune diseases such as multiple sclerosis (MS) and diabetes, today announced additional positive data from the company’s Phase IIb TERMS clinical trial (Tovaxin® for Early Relapsing Multiple Sclerosis). The latest analysis focused on a prospective group of patients (n=50) with an annualized relapse rate (ARR) of greater than 1 at study entry which is comparable to ARR baselines of patients in previous Tovaxin studies. These findings demonstrate a statistically significant improvement in disability as measured by the Expanded Disability Status Scale (EDSS) (p=0.045) for patients treated with Tovaxin as compared to those receiving placebo. In this group, 28.1 percent of patients treated with Tovaxin showed an improvement in EDSS as compared to only 5.6 percent in the placebo group. Additionally, there was an 88 percent reduction in the level of brain atrophy and a more than 20 percent reduction in the number of gadolinium (Gd) lesions progressing to black holes in the Tovaxin group, which may suggest a beneficial neuroprotective effect. Overall, the analysis shows that patients treated with Tovaxin demonstrated a benefit across all clinical and magnetic resonance imaging (MRI) endpoints (primary, secondary and tertiary) in this patient population. Immunology data also appears to support Tovaxin’s mechanism of action, indicating that patients with less myelin T-cell reactivity have a lower risk of relapse. Additional quality of life measurements, such as the Timed 25 foot Walk, also showed a benefit for Tovaxin over placebo (0.14 vs. -0.02, as measured by respective Z scores).

The data shows that these patients when treated with Tovaxin demonstrate an ARR of 0.28 which represents a 55 percent reduction compared to those patients on placebo. This relapse rate is on par with the lowest relapse rates observed with currently available MS treatments which range from 0.2 to 0.9. Study findings also show Tovaxin possesses an impressive safety and tolerability profile. Opexa expects to conduct a Phase II close-out meeting with the United States Food and Drug Administration during the first half of 2009 to discuss next steps for the further clinical development of Tovaxin. Opexa is actively engaged in discussions with potential strategic partners for the Tovaxin program.

The TERMS study provided Opexa the opportunity to create a comprehensive database of clinical immunology and epitope data in MS patients that may significantly advance the understanding and treatment of the disease. This type of information is particularly important for Opexa as Tovaxin’s dual mechanism of action involves the depletion of myelin-reactive T-cells in the peripheral blood and the regulation of anti-inflammatory T-cells to rebalance an MS patient’s immune system. Previous studies show that if the myelin-peptide reactivity in a patient’s peripheral blood is reduced, the clinical symptoms associated with MS will also be reduced. The initial analysis of the study’s immunology and epitope database has shown that patients treated with Tovaxin appeared to have less myelin-peptide reactivity over the course of the study than those on placebo. This was measured using Opexa’s proprietary Epitope Analysis Assay (EAA) which assessed reactivity across all three key myelin proteins at several time points throughout the 52-week study. Additionally, over the full course of treatment, more patients on Tovaxin remained in the lower quartile of peptide reactivity (56 percent) than those on placebo (39 percent). This epitope data appears to correlate with the study’s MRI and clinical endpoints which, among other findings, showed that following the full course of treatment (weeks 28-52), the ARR in the Tovaxin group dropped to 0.065 (0.749 for placebo).

The pattern emerging from the analysis of the immunology and epitope database suggests that those patients exhibiting a higher T-cell reactivity often demonstrated a worsening of at least one MRI endpoint (Gd lesion, Gd volume, new T2 count or progression to black holes) and one clinical endpoint (either relapse or EDSS). The converse also appears true with less T-cell reactivity implying less or no worsening of certain MRI and clinical endpoints.

Additionally, the immunology data shows that reactivity to all three of the key myelin proteins (MOG, PLP and MBP) was broadly present in study patients, which may be an important finding for the future treatment of MS. Opexa is also assessing which specific peptides from each of the proteins may provide the most relevant targets for the company to enhance its manufacturing process and further strengthen its intellectual property portfolio.

“Tovaxin seems to be demonstrating a benefit to these patients as indicated by immunology, MRI and clinical parameters,” stated Dr. Clyde Markowitz, associate professor of neurology and director of the MS center at the University of Pennsylvania School of Medicine. “This is interesting data and additional trials are certainly warranted to further explore the potential of this novel treatment.”

Previously reported top-line results from the TERMS study demonstrated that Tovaxin was safe and well tolerated with no serious adverse events related to treatment. The most common adverse event related to Tovaxin was mild injection site reaction. Continued analysis of safety and tolerability data has confirmed these top-line results with no serious adverse events observed in any Tovaxin-treated patients during the entire study.

“This landmark first-in-class study has yielded impressive results for Tovaxin in MS patients with high disease burden, including a marked reduction in disability, relapse risk and levels of T-cell reactivity. These findings are very encouraging and we are eager to continue the clinical development of this novel therapeutic,” commented Neil K. Warma, president and chief executive officer of Opexa Therapeutics. “There remains a tremendous unmet medical need for MS patients, and we believe a safe and effective patient-specific treatment may generate considerable interest among regulatory authorities, patients, physicians and potential strategic partners. With this in mind, we remain committed to aggressively pursuing our two primary objectives: the continued development of Tovaxin towards a pivotal Phase III trial and a high-value partnership for the Tovaxin program. With the MS market exceeding $6 billion and growing, we believe Tovaxin is very competitively positioned from a safety, efficacy and patient compliance perspective.”

About Tovaxin

Tovaxin is an individualized T-cell therapeutic vaccine that consists of attenuated patient-specific myelin-reactive T-cells (MRTCs) against peptides of proteins from Myelin basic protein (MBP), Myelin oligodendrocyte glycoprotein (MOG) and Proteolipid protein (PLP) or combinations thereof. Tovaxin’s dual mechanism of action combats the demyelination of the nerve fibers in the central nervous system, the underlying cause of MS. Clinical results have demonstrated that Tovaxin produces the following therapeutic effects:

* Anti-idiotypic effect – Induces an immune response that depletes and regulates the circulating pathogenic myelin-reactive T-cells that attack the myelin sheath of nerve fibers.
* Anti-ergotypic effect – Rebalances the overall immune system by causing a shift from pathogenic inflammatory T-cells to anti-inflammatory T-cells.

Tovaxin is manufactured in Opexa’s in-house cGMP facility.

About the TERMS Study

The TERMS study was a Phase IIb multi-center, randomized, double blind, placebo-controlled trial in 150 patients with Relapsing-Remitting Multiple Sclerosis or high risk Clinically Isolated Syndrome (CIS). The study involved 2:1 randomization with 100 patients receiving Tovaxin and 50 receiving placebo. According to the study protocol, patients received a total of five subcutaneous injections at weeks 0, 4, 8, 12 and 24. The primary efficacy endpoint of the TERMS trial was the cumulative number of gadolinium-enhanced brain lesions (CELs) using MRI scans summed over weeks 28, 36, 44 and 52. The trial’s secondary efficacy endpoints included annualized relapse rate (ARR), new CELs at weeks 28 through 52 and T2-weighted lesion volume compared to baseline.


About Opexa

Opexa Therapeutics develops and commercializes cell therapies to treat autoimmune diseases such as multiple sclerosis, rheumatoid arthritis and diabetes. The Company is focused on autologous cellular therapy applications of its proprietary T-cell and stem cell therapies. The Company's lead product is Tovaxin, a T-cell therapy for multiple sclerosis is in Phase IIb trials. The Company holds the exclusive worldwide license for adult multipotent stem cells derived from mononuclear cells of peripheral blood. The technology allows large quantities of monocyte-derived stem cells to be produced efficiently for use in autologous therapy, thus circumventing the threat of rejection. The Company is in preclinical development for diabetes mellitus. For more information visit the Opexa Therapeutics website at www.opexatherapeutics.com.

Cautionary Statement Relating to Forward - Looking Information for the Purpose of "Safe Harbor" Provisions of the Private Securities Litigation Reform Act of 1995

This press release contains forward-looking statements which are made pursuant to the safe harbor provisions of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. The forward-looking statements in this release do not constitute guarantees of future performance. Investors are cautioned that statements in this press release which are not strictly historical statements, including, without limitation, statements regarding current or future financial performance and position, management's strategy, plans and objectives for future operations, plans and objectives for product development, plans and objectives for present and future clinical trials and results of such trials, plans and objectives for regulatory approval, litigation, intellectual property, product development, manufacturing plans and performance, constitute forward-looking statements. Such forward-looking statements are subject to a number of risks and uncertainties that could cause actual results to differ materially from those anticipated, including, without limitation, risks associated with: the success of collaborative relationships, our ability to compete with larger, better financed pharmaceutical and biotechnology companies, new approaches to the treatment of our targeted diseases, our expectation of incurring continued losses, our uncertainty of developing a marketable product, our ability to raise additional capital to continue our treatment development programs, the success of our clinical trials, our ability to develop and commercialize products, our ability to obtain required regulatory approvals, our compliance with all Food and Drug Administration regulations, our ability to obtain, maintain and protect intellectual property rights for our products, the risk of litigation regarding our intellectual property rights, our limited manufacturing capabilities, our dependence on third-party manufacturers and value added resellers, our ability to hire and retain skilled personnel, our volatile stock price, and other risks detailed in our filings with the Securities and Exchange Commission. We assume no obligation to update any forward-looking information contained in this press release or with respect to the announcements described herein.

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Opexa Announces Top-Line Results from Phase IIb Clinical Trial of Tovaxin® for the Treatment of Multiple Sclerosis

September 19, 2008 02:55 PM Eastern Daylight Time

Tovaxin Shows Favorable Annualized Relapse Rate and Excellent Safety Profile

MONTREAL--(BUSINESS WIRE)--Opexa Therapeutics, Inc. (NASDAQ:OPXA), a company dedicated to the development of patient-specific cellular therapies for the treatment of autoimmune diseases such as multiple sclerosis (MS) and diabetes, today announced top-line data from the company’s Phase IIb TERMS (Tovaxin® for Early Relapsing Multiple Sclerosis) study. Top-line results from the study demonstrated a positive trend in the reduction in annualized relapse rate (ARR) 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 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 percent 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 percent 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. The most common adverse event related to Tovaxin was mild injection site reaction. 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 MS treatments.

It is important to note that 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.

“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,” stated Neil K. Warma, president and chief executive officer of Opexa. “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.”

Top-line data from the TERMS study were presented today by Edward J. Fox, M.D., Ph.D., director of the Multiple Sclerosis Clinic of Central Texas and the study’s principal investigator, at the World Congress on Treatment and Research in Multiple Sclerosis in Montreal, Canada.

“Multiple sclerosis is a disease that affects individual patients in distinctly different ways, highlighting the desire for a safe, effective and patient-specific therapy such as Tovaxin. With this in mind, we are pleased with the positive efficacy trend and excellent safety results witnessed in the TERMS study,” stated Dr. Fox. “The Tovaxin-induced reduction in ARR is particularly exciting as it suggests a reduction of clinical activity associated with MS. These study results are encouraging and supportive of further analysis of Tovaxin.”

About the TERMS Study

The TERMS study was a Phase IIb multi-center, randomized, double blind, placebo-controlled trial in 150 patients with Relapsing-Remitting Multiple Sclerosis or high risk Clinically Isolated Syndrome (CIS). The study involved 2:1 randomization with 100 patients receiving Tovaxin and 50 receiving placebo. According to the study protocol, patients received a total of five subcutaneous injections at weeks 0, 4, 8, 12 and 24. The primary efficacy endpoint of the TERMS trial was the cumulative number of gadolinium-enhanced brain lesions (CELs) using MRI scans summed over weeks 28, 36, 44 and 52. The trial’s secondary efficacy endpoints included annualized relapse rate (ARR), new CELs at weeks 28 through 52 and T2-weighted lesion volume compared to baseline.

Top-line data from the TERMS trial is as follows:

* ARR for Tovaxin-treated patients was 0.214 as compared to 0.339 for placebo-treated patients. Consistent with ARRs seen in previously conducted clinical trials for Tovaxin, this result is at the lower end of the spectrum of documented relapse rates demonstrated in controlled two-year clinical studies of currently marketed products (range from 0.2 to 0.9).

* For patients who had an ARR > 1 in the year prior to the study, Tovaxin demonstrated a 55 percent reduction in ARR as compared to placebo.

* Tovaxin was safe and well tolerated with no serious adverse events related to Tovaxin treatment. The most common adverse event was injection site irritation.

* Only 18 patients (12 percent) withdrew from the study prior to completion. The dropout percentage was identical for the Tovaxin and placebo arms of the study, providing further evidence of Tovaxin’s excellent safety and tolerability.

“We are especially pleased with the TERMS study’s ARR results, as this represents the most common efficacy endpoint evaluated by the FDA when approving MS therapeutics. Opexa expects that ARR will serve as the primary endpoint in any pivotal Phase III Tovaxin study,” commented Mr. Warma.

Opexa intends to complete a comprehensive analysis of all data from the TERMS study over the next several months. Based on the TERMS study results, Opexa expects to conduct a Phase II close-out meeting with the United States Food and Drug Administration during the first half of 2009. This meeting, along with the comprehensive results of the TERMS study, will provide important guidance as Opexa plans to advance Tovaxin into Phase III development.

Additionally, Opexa is conducting a one-year, open-label extension trial of the TERMS study called OLETERMS. Approximately 90 percent of patients in the TERMS study have elected to enroll in the OLETERMS trial.

Investigator Q&A Session

Opexa will host an investigator Q&A session following the conclusion of today’s programs at the World Congress on Treatment and Research in Multiple Sclerosis. A live webcast of the Q&A session will be available on Opexa’s web site at www.opexatherapeutics.com beginning at 6:00pm Eastern. The webcast will be archived until October 19, 2008.

Conference Call and Webcast

Opexa will host a conference call and webcast with company management to discuss the Phase IIb TERMS data and provide a corporate update on Monday, September 22, 2008, at 8:30 a.m. Eastern. The conference call can be accessed by dialing 800-230-1074 from the U.S. and 612-332-0228 internationally. Additionally a live webcast of the call will be available on Opexa’s web site at www.opexatherapeutics.com. The webcast will be archived until October 22, 2008.

A replay of the call can be accessed until September 29, 2008 at 11:59 p.m., by dialing 800-475-6701 from the U.S. and 320-365-3844 internationally, and entering the following access code: 960761.

About Tovaxin

Tovaxin is developed using Opexa’s proprietary method for the production of patient-specific T-cell vaccines. To produce the Tovaxin vaccine, Opexa isolates disease-causing T-cells from blood taken from an MS patient and expands them in the laboratory to create an appropriate therapeutic dose. The attenuated T-cells, which comprise the Tovaxin vaccine, are reintroduced into the patient via subcutaneous injection to trigger a therapeutic immune system response. Tovaxin is manufactured in Opexa’s in-house cGMP facility.

Opexa believes that Tovaxin may possess the following competitive advantages:

* Efficacy – Clinical trials conducted to date demonstrate that Tovaxin may result in a reduction in ARR (a key measure of MS treatment effectiveness) for patients with Clinically Isolated Syndrome (CIS), Relapsing-Remitting MS (RRMS) and Secondary-Progressive MS (SPMS) patients comparable to currently available MS therapeutics.
* Safety and Tolerability – Tovaxin treatment selectively targets and depletes the pathogenic T-cell population. It is not a general immune suppressant and accordingly, is not associated with the serious side effects seen with those MS treatments that function by systemically suppressing the immune system. In clinical trials conducted to date, including the 150-patient Phase IIb study, there have been no serious adverse events associated with Tovaxin treatment.

* Improved Compliance – In clinical trials, Tovaxin is administered only five times per year. This patient-friendly treatment regimen may provide significant compliance benefits compared to currently available MS treatments (at least once per month and, in some cases, as frequently as every day.

* Customized Therapy – Using the company’s proprietary Epitope Analysis Assay (EAA) to profile an individual’s disease profile, Opexa can continually customize treatments to specifically target an individual’s disease progression and/or modification.

About Opexa Therapeutics

Opexa Therapeutics is a biotechnology company dedicated to the development of patient-specific cellular therapies for the treatment of autoimmune diseases. The company’s leading therapies currently in development have the potential to address significant unmet medical needs in several large patient populations including multiple sclerosis (MS) and diabetes. The company's lead product is Tovaxin, a T-cell therapy for MS which recently completed a Phase IIb trial. The company also holds an exclusive worldwide license for adult multi-potent stem cells derived from mononuclear cells of peripheral blood. The technology provides means to differentiate these stem cells into other tissue types such as pancreatic islets. By using an individual’s own cells, this approach may minimize threat of treatment rejection. This technology serves as the basis for Opexa’s preclinical diabetes program, which is focused on the generation of insulin-secreting pancreatic-like cells. For more information visit the Opexa Therapeutics website at www.opexatherapeutics.com.

Cautionary Statement Relating to Forward - Looking Information for the Purpose of "Safe Harbor" Provisions of the Private Securities Litigation Reform Act of 1995

This press release contains forward-looking statements which are made pursuant to the safe harbor provisions of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. The forward-looking statements in this release do not constitute guarantees of future performance. Investors are cautioned that statements in this press release which are not strictly historical statements, including, without limitation, statements regarding current or future financial performance and position, management's strategy, plans and objectives for future operations, plans and objectives for product development, plans and objectives for present and future clinical trials and results of such trials, plans and objectives for regulatory approval, litigation, intellectual property, product development, manufacturing plans and performance, constitute forward-looking statements. Such forward-looking statements are subject to a number of risks and uncertainties that could cause actual results to differ materially from those anticipated, including, without limitation, risks associated with: the success of collaborative relationships, our ability to compete with larger, better financed pharmaceutical and biotechnology companies, new approaches to the treatment of our targeted diseases, our expectation of incurring continued losses, our uncertainty of developing a marketable product, our ability to raise additional capital to continue our treatment development programs, the success of our clinical trials, our ability to develop and commercialize products, our ability to obtain required regulatory approvals, our compliance with all Food and Drug Administration regulations, our ability to obtain, maintain and protect intellectual property rights for our products, the risk of litigation regarding our intellectual property rights, our limited manufacturing capabilities, our dependence on third-party manufacturers and value added resellers, our ability to hire and retain skilled personnel, our volatile stock price, and other risks detailed in our filings with the Securities and Exchange Commission. We assume no obligation to update any forward-looking information contained in this press release or with respect to the announcements described herein.
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Opexa Conducts Additional Analysis on Phase I/II Extension Study with Tovaxin® for Multiple Sclerosis

July 22, 2008

Annual treatments with patient specific vaccine appear beneficial

THE WOODLANDS, Texas--(BUSINESS WIRE)--Opexa Therapeutics, Inc. (NASDAQ:OPXA), a company leading in the development of cell therapies for multiple sclerosis (MS) and diabetes, has completed an internal assessment of data from its Phase I/II two year extension study with Tovaxin in patients with MS. While confirming the favorable safety and efficacy profile of Tovaxin, further analysis also confirms both the benefit of consecutive annual treatments with Tovaxin and the advantage of tailoring each vaccination to the patient’s changing disease profile.

The extension study evaluated 22 intent-to-treat patients that had enrolled in two Phase I/II open-label clinical studies with Tovaxin. 13 patients were enrolled with Relapse Remitting Multiple Sclerosis (RRMS) and 9 with Secondary Progressive Multiple Sclerosis (SPMS). After the first annual course of treatment the company conducted an analysis of each patient’s specific disease profile and myelin peptide epitope profile using Opexa’s proprietary Epitope Analysis Assay (EAA). The analysis showed that 19 of the 22 patients (86%) had undergone an epitope shift, or change in disease pattern since the original course of treatment. Based on the epitope analysis, Opexa manufactured a new and specific vaccine for each of these patients for their second course of treatment. This enabled Opexa to tailor each vaccine to the individual’s current disease profile, thereby maximizing the effect.

The treatment regimen of five subcutaneous injections per year for each of the two years with two different vaccines tailored to each patient’s disease profile produced promising results. Pooled data from the RRMS and SPMS patients showed that, as a group, 73% remained relapse free after two years and 86% demonstrated no worsening of disease (27% of these showed sustained improvement). Additionally, there was an overall decrease in the Annualized Relapse Rate (ARR) of 82% (from 1.38 to 0.21 relapses/patient/year). Each of these endpoints was compared to the patient’s own baseline reading, taken prior to enrollment in the trials.

A further analysis of several effectiveness parameters showed that Tovaxin effectively decreased the number of circulating Myelin Reactive T-Cells (MRTCs) but did not cause any detectable reduction in the general lymphocyte populations. The lack of generalized immune suppression observed at this stage of development is one important aspect that distinguishes the safety of Tovaxin from certain marketed drugs. Side effects observed over the two year treatment period have been limited to moderate injection site reactions. There have been no serious adverse events related to treatment.

“The results from this extension study support our clinical strategy for Tovaxin of annual treatments tailored to each patient’s clinical disease state,” commented Dr. Jim Williams, Opexa’s Chief Operating Officer. “And although the safety and efficacy data from the two year Tovaxin studies are based on a limited MS patient sample across two open-label clinical studies, comparing the annualized relapse rates of the RRMS patient population treated with Tovaxin at 0.2, places this treatment at the lower end of documented relapse rates of the major marketed drugs which range from 0.2-0.9. We believe Tovaxin’s safety profile and a treatment regimen of five subcutaneous injections per year will also position the therapy favorably from a patient compliance perspective,” added Dr. Williams.

The company is currently completing a larger Phase IIb study in 150 patients in a multi-center, randomized, double blind, and placebo-controlled study in patients with RRMS or Clinically Isolated Syndrome (CIS). The company expects to announce top line results in September 2008.

About Tovaxin

Tovaxin is an autologous attenuated whole T-cell vaccine manufactured by specifically selecting MRTCs from a patient’s blood, and expanding them ex-vivo to a therapeutic dose. In this way, the vaccine is tailored to each patient’s disease state. The reintroduction of the attenuated T-cells via subcutaneous inoculation induces an immune response against the MRTCs, thereby triggering the immune system to attack the pathogenic T-cells in the body.

Treatment with Tovaxin results in a decrease in the number of pathogenic T-cells by anti-idiotypic mechanisms and restores the immune regulatory network by anti-ergotypic immune responses. Although Tovaxin administration results in the depletion and regulation of pathogenic T-cells, there is no generalized immune suppression.

About Opexa

Opexa Therapeutics develops and commercializes cell therapies to treat autoimmune diseases such as multiple sclerosis, rheumatoid arthritis and diabetes. The Company is focused on autologous cellular therapy applications of its proprietary T-cell and stem cell therapies. The Company's lead product is Tovaxin, a T-cell therapy for multiple sclerosis which is in Phase IIb trials. The Company holds an exclusive worldwide license for adult multipotent stem cells derived from mononuclear cells of peripheral blood. The technology allows large quantities of monocyte-derived stem cells to be produced efficiently for use in autologous therapy, thus circumventing the threat of rejection. The Company is in the preclinical stages of the development of insulin-producing monocyte-derived islets as a replacement therapy for diabetes mellitus. For more information visit the Opexa Therapeutics website at www.opexatherapeutics.com.

Cautionary Statement Relating to Forward-Looking Information for the Purpose of "Safe Harbor" Provisions of the Private Securities Litigation Reform Act of 1995

This press release contains "forward-looking statements," including statements about Opexa Therapeutics' growth and future operating results, discovery and development of products, strategic alliances and intellectual property, as well as other matters that are not historical facts or information. These forward-looking statements are based on management's current assumptions and expectations and involve risks, uncertainties and other important factors, specifically including those relating to Opexa Therapeutics' ability to obtain additional funding, develop its stem cell technologies, obtain FDA approval for its therapeutic products, achieve its operational objectives, and obtain patent protection for its discoveries, that may cause Opexa Therapeutics' actual results to be materially different from any future results expressed or implied by such forward-looking statements. Opexa Therapeutics undertakes no obligation to update or revise any such forward-looking statements, whether as a result of new information, future events or otherwise.

Opexa’s Phase IIb Study of Tovaxin® Receives Positive Review from Data Safety Monitoring Board

THE WOODLANDS, Texas--(BUSINESS WIRE)--Opexa Therapeutics, Inc. (NASDAQ:OPXA), a company leading in the development of cell therapies for multiple sclerosis announced today that the Data Safety Monitoring Board (DSMB) overseeing the on-going Phase IIb clinical study of Tovaxin has recommended that the trial continue unmodified. This positive recommendation follows a regularly scheduled meeting of the DSMB in June and is based upon an evaluation of clinical, magnetic resonance imaging (MRI) and safety data that had been recorded for all patients to date.

The TERMS trial (Tovaxin for Early Relapsing Multiple Sclerosis) is nearing completion and the DSMB has two additional scheduled meetings in July and August of this year. Tovaxin is being evaluated in a multi-center, randomized, double blind, placebo controlled study in 150 patients suffering from Relapse Remitting Multiple Sclerosis (RRMS) or Clinically Isolated Syndrome (CIS).

The trial was initiated in the third quarter of 2006 and enrollment was completed in the second quarter of 2007. Dosing was completed in the first quarter of 2008 and currently patients are completing their final weeks 44 and 52 follow-up visits. The primary endpoint being evaluated in this trial is the cumulative number of contrast (gadolinium) enhancing brain lesions (CEL) using MRI, an important and objective measure of MS disease activity. Secondary endpoints include Annualized Relapse Rate (ARR) and additional MRI measurements.

Opexa expects to announce top line results in September 2008.

About Tovaxin

Tovaxin is an individualized T-cell therapeutic vaccine that consists of attenuated patient-specific myelin-reactive T-cells (MRTCs) against peptides of proteins from Myelin basic protein (MBP), Myelin oligodendrocyte glycoprotein (MOG) and Proteolipid protein (PLP) or combinations thereof. Recently announced two-year follow up data from Phase I/II clinical studies of 22 patients showed 73% of patients on Tovaxin remained relapse free after two years with 86% experiencing no disease progression. Tovaxin is manufactured in Opexa’s in-house cGMP facility.

About Opexa

Opexa Therapeutics develops and commercializes cell therapies to treat autoimmune diseases such as multiple sclerosis, rheumatoid arthritis and diabetes. The Company is focused on autologous cellular therapy applications of its proprietary T-cell and stem cell therapies. The Company's lead product is Tovaxin, a T-cell therapy for multiple sclerosis is in Phase IIb trials. The Company holds the exclusive worldwide license for adult multipotent stem cells derived from mononuclear cells of peripheral blood. The technology allows large quantities of monocyte-derived stem cells to be produced efficiently for use in autologous therapy, thus circumventing the threat of rejection. The Company is in preclinical development for diabetes mellitus. For more information visit the Opexa Therapeutics website at www.opexatherapeutics.com.

Cautionary Statement Relating to Forward - Looking Information for the Purpose of "Safe Harbor" Provisions of the Private Securities Litigation Reform Act of 1995

This press release contains "forward-looking statements," including statements about Opexa Therapeutics' growth and future operating results, discovery and development of products, strategic alliances and intellectual property, as well as other matters that are not historical facts or information. These forward-looking statements are based on management's current assumptions and expectations and involve risks, uncertainties and other important factors, specifically including those relating to Opexa Therapeutics' ability to obtain additional funding, develop its stem cell technologies, obtain FDA approval for its therapeutic products, achieve its operational objectives, and obtain patent protection for its discoveries, that may cause Opexa Therapeutics' actual results to be materially different from any future results expressed or implied by such forward-looking statements. Opexa Therapeutics undertakes no obligation to update or revise any such forward-looking statements, whether as a result of new information, future events or otherwise.

Opexa Therapeutics Reports Favorable Two-Year Data in Phase I/II Retreatment Studies of Tovaxin® for Multiple Sclerosis

73% of patients remained relapse-free at two years

THE WOODLANDS, Texas--(BUSINESS WIRE)--Opexa Therapeutics, Inc. (NASDAQ:OPXA), a cell therapy development and commercialization company, today announced favorable safety and efficacy data for Tovaxin®, the Company’s investigational T-cell vaccination therapy for multiple sclerosis (MS), in the second year of open-label clinical retreatment studies in patients with MS.

The “intent to treat” population of 22 patients included 13 with relapsing remitting multiple sclerosis (RRMS) and nine with secondary progressive multiple sclerosis (SPMS). An analysis of disease progression of disability over a two year period, as measured by a 1.0 or greater change in Expanded Disability Scoring Scale (EDSS), showed that 27.3% of patients demonstrated sustained improvement, 59.1% had no disease progression and 13.6% experienced sustained worsening of disability. The improvement in the EDSS scores ranged from 1.0 to 4.5 (average 2.41). During the two-year study period 72.7% of patients remained relapse-free.

Brian Loftus, M.D., of Bellaire Neurology and the principal investigator of the studies, commented, “I’m pleased to see that subjects in the study experienced sustained positive clinical outcomes over the two-year period. It was especially encouraging to see a lack of disease progression in more than 86% of the patients after two years, given the later stage of disease of this subject population.”

The annualized relapse rate analysis of 17 patients (which excludes five patients with no prior relapses in their two-year pre-study baseline) showed Tovaxin therapy achieved an 82% reduction in annualized relapse rate (ARR) in patients over a two-year period (p<0.0001) to 0.21 relapses per year, compared with 1.38 relapses per year in the patients’ prior two-year baseline. For RRMS patients (n=12) the ARR over a two-year period was 0.26 relapses per year, compared with 1.63 relapses per year in the patients’ prior two-year baseline; for SPMS patients (n=5) the ARR over a two-year period was 0.10 relapses per year, compared with 0.80 relapses per year in the patients’ prior two-year baseline.

“Approximately three out of four patients re-treated in the second year exhibited a change in their myelin-reactive T-cell profile, which was the basis for producing their individualized T cell vaccine,” said David McWilliams, president and chief executive officer of Opexa. “We believe this new data supports the continuation of our development strategy of individually monitoring patients with our proprietary epitope analysis assay and re-treating them with a patient-specific therapeutic vaccine that associates with their clinical status.”

The combined analysis included patients participating in second-year extension protocols from the Phase I/II dose-escalation study and the Phase I/II re-treatment study, and 19 of 22 patients were re-treated with Tovaxin during the study period. Patients did not receive any other disease modifying therapies during the two-year study period.

Tovaxin was well-tolerated throughout the two-year study period. The safety profile revealed only mild-to-moderate injection site reactions and no serious adverse reactions related to T-cell vaccination.

About Multiple Sclerosis

In the U.S. approximately 400,000 people suffer from MS, a chronic progressive autoimmune disease of the central nervous system that is caused by myelin autoreactive T-cells progressively eroding the myelin that surrounds and insulates nerve fibers of the brain and spinal cord resulting in varying amounts of disability. Globally, there are approximately 2.5 million MS patients representing a drug therapy market believed to be approximately $5 billion in 2005. The US markets accounted for slightly more than half of global MS sales in 2005.

MS remains a challenging autoimmune disease to treat because the pathophysiologic mechanisms are diverse, and the chronic, unpredictable course of the disease makes it difficult to determine whether the favorable effects of short-term treatment will be sustained. Therapies that are easy to use and can safely prevent or stop the progression of disease represent the greatest unmet need in MS. The most common phase of MS at the time of diagnosis is relapsing-remitting, which affects approximately 70% of MS patients. This group experiences clearly defined flare-ups (relapses), followed by partial or complete remissions between attacks that are free of disease progression. Approximately 50% of the relapsing-remitting patients develop the secondary-progressive form of the disease within 10 years of diagnosis. This phase is characterized by an initial period of relapsing-remitting disease followed by steady worsening with or without flares or minor remissions.

About Tovaxin for Multiple Sclerosis

Tovaxin is an individualized T-cell therapeutic vaccine that consists of attenuated patient-specific myelin-reactive T-cells (MRTCs) against peptides of proteins from Myelin basic protein (MBP), Myelin oligodendrocyte glycoprotein (MOG) and Proteolipid protein (PLP) or combinations thereof. Patient-specific MRTCs are expanded in culture with specific peptides identified by assaying peripheral blood mononuclear cell reactivity against peptides derived from the three myelin proteins. Studies have shown that T-cell vaccination resulted in the in vivo induction of CD8+ cytotoxic T-cells and CD4+CD25+FoxP3 Tregs specific for T-cell vaccine. The induction of anti-idiotypic cytotoxic CD8+ effector T-cells and anti-ergotypic CD4+CD25+FoxP3 positive Tregs is believed to provide a therapeutically effective dual mechanism of protection to patients treated with Tovaxin. The observed regulatory immune responses have been shown to collectively relate with clinical improvement in treated patients. Tovaxin has been previously studied in two Phase I/II open-label trials. A 150-patient Phase IIb one-year double blind placebo controlled study to evaluate the efficacy, safety and tolerability of Tovaxin in subjects with clinically isolated syndrome (CIS) or relapse-remitting multiple sclerosis (RR-MS) is nearing completion.

About Opexa Therapeutics

Opexa Therapeutics develops and commercializes cell therapies to treat autoimmune diseases such as multiple sclerosis, rheumatoid arthritis and diabetes. The Company is focused on autologous cellular therapy applications of its proprietary T-cell and stem cell therapies. The Company's lead product is Tovaxin, a T-cell therapy for multiple sclerosis is in Phase IIb trials. The Company holds the exclusive worldwide license for adult multipotent stem cells derived from mononuclear cells of peripheral blood. The technology allows large quantities of monocyte-derived stem cells to be produced efficiently for use in autologous therapy, thus circumventing the threat of rejection. The Company is in preclinical development for diabetes mellitus. For more information visit the Opexa Therapeutics website at www.opexatherapeutics.com.

Cautionary Statement Relating to Forward-Looking Information for the Purpose of "Safe Harbor" Provisions of the Private Securities Litigation Reform Act of 1995

This press release contains "forward-looking statements," including statements about Opexa Therapeutics' growth and future operating results, discovery and development of products, strategic alliances and intellectual property, as well as other matters that are not historical facts or information. These forward-looking statements are based on management's current assumptions and expectations and involve risks, uncertainties and other important factors, specifically including those relating to Opexa Therapeutics' ability to obtain additional funding, develop its stem cell technologies, obtain FDA approval for its therapeutic products, achieve its operational objectives, and obtain patent protection for its discoveries, that may cause Opexa Therapeutics' actual results to be materially different from any future results expressed or implied by such forward-looking statements. Opexa Therapeutics undertakes no obligation to update or revise any such forward-looking statements, whether as a result of new information, future events or otherwise.

Opexa Therapeutics Presents Tovaxin Phase I/II Data at the American Academy of Neurology 60th Annual Meeting

THE WOODLANDS, Texas--(BUSINESS WIRE)--Opexa Therapeutics, Inc. (NASDAQ:OPXA), a company involved in the development and commercialization of cell therapies, today announced that Brian Loftus, M.D., of Bellaire Neurology and the Principal Investigator of the Tovaxin Phase I/II studies, presented data titled “Autologous Attenuated T-Cell Vaccine (Tovaxin®) Dose Escalation in Multiple Sclerosis Relapse-Remitting and Secondary Progressive Patients Nonresponsive to Approved Immunomodulatory Therapies” at the American Academy of Neurology meeting today. The AAN meeting is taking place at the McCormick Place West Convention Center in Chicago, IL.

The objective of the Tovaxin Phase I/II dose escalation study was to assess the safety and effectiveness of T cell vaccine (Tovaxin®) in MS patients non-responsive to approved immunomodulatory therapies. The trial results indicate statistically significant improvements from baseline observed using the annualized relapse rate and myelin-reactive T-cell count effectiveness measurements.

“The positive therapeutic effects of safety, early effectiveness and tolerability observed in this study suggest that depletion of myelin-reactive T-cells using Tovaxin, a trivalent T-cell vaccine, may be an appropriate treatment strategy for patients with MS and warrants further study,” said Dr. Loftus.

About T-cell Vaccination

For a T-cell vaccine to be effective, it should be able to induce T-cell cytotoxic and/or regulatory immune responses against the pathogenic T-cells. Studies of T-cell vaccine have indicated that T-cell vaccination with peripheral blood-derived autologous myelin-peptide selected T-cells in multiple sclerosis patients resulted in the in vivo induction of CD8+ cytotoxic T-cells and CD4+CD25+FoxP3 Tregs specific for T-cell vaccine. The induction of anti-idiotypic cytotoxic CD8+ effector T-cells and anti-ergotypic CD4+CD25+FoxP3 positive Tregs is believed to provide a therapeutically effective dual mechanism of protection to patients treated with Tovaxin. The observed regulatory immune responses have been shown to collectively correlate with clinical improvement in some patients treated in earlier clinical studies.

About Opexa Therapeutics

Opexa Therapeutics develops and commercializes cell therapies to treat autoimmune diseases such as MS, rheumatoid arthritis, and diabetes. The Company is focused on autologous cellular therapy applications of its proprietary T-cell and stem cell therapies. The Company's lead product, Tovaxin, a T-cell therapy for multiple sclerosis is in Phase IIb trials. The Company holds the exclusive worldwide license for adult multipotent stem cells derived from mononuclear cells of peripheral blood. The technology allows large quantities of monocyte derived stem cells to be produced efficiently for use in autologous therapy, thus circumventing the threat of rejection. The Company is in preclinical development for diabetes mellitus. For more information, visit the Opexa Therapeutics website at www.opexatherapeutics.com.

Cautionary Statement Relating to Forward - Looking Information for the Purpose of "Safe Harbor" Provisions of the Private Securities Litigation Reform Act of 1995

This press release contains "forward-looking statements," including statements about Opexa Therapeutics' growth and future operating results, discovery and development of products, strategic alliances and intellectual property, as well as other matters that are not historical facts or information. These forward-looking statements are based on management's current assumptions and expectations and involve risks, uncertainties and other important factors, specifically including those relating to Opexa Therapeutics' ability to obtain additional funding, develop its stem cell technologies, obtain FDA approval for its therapeutic products, achieve its operational objectives, and obtain patent protection for its discoveries, that may cause Opexa Therapeutics' actual results to be materially different from any future results expressed or implied by such forward-looking statements. Opexa Therapeutics undertakes no obligation to update or revise any such forward-looking statements, whether as a result of new information, future events or otherwise.

Opexa Therapeutics Receives European Patent Notification for T-Cell Vaccine

THE WOODLANDS, Texas--(BUSINESS WIRE)--Opexa Therapeutics, Inc. (NASDAQ:OPXA), a company involved in the development and commercialization of cell therapies, today announced that it has received notification under Rule 51(4) from the Examining Division of the European Patent Office (EPO) that the EPO intends to issue a patent for “Autologous T Cell Vaccine Materials and Method.” The European patent application is related to a unique method-specific approach for generating a T-cell vaccine that attacks what is believed to be the underlying cause of multiple sclerosis (MS). Rule 51(4) EPC notification is equivalent to a “Notice of Allowance” by the United States Patent and Trademark Office. It is expected that the patent will be granted within the next six months.

David McWilliams, president and chief executive officer of Opexa Therapeutics, commented, “This is an important step in advancing our intellectual property strategy for Tovaxin®, T-cell vaccine for the treatment of MS. Europe represents a significant market as we move forward with our clinical development of Tovaxin and we are pleased that our method has been recognized as being unique.”

About T-cell Vaccination

For a T-cell vaccine to be effective, it should be able to induce T-cell cytotoxic and/or regulatory immune responses against the pathogenic T-cells. Studies of T-cell vaccine have indicated that T-cell vaccination with peripheral blood-derived autologous myelin-peptide selected T-cells in multiple sclerosis patients resulted in the in vivo induction of CD8+ cytotoxic T-cells and CD4+CD25+FoxP3 Tregs specific for T-cell vaccine. The induction of anti-idiotypic cytotoxic CD8+ effector T-cells and anti-ergotypic CD4+CD25+FoxP3 positive Tregs is believed to provide a therapeutically effective dual mechanism of protection to patients treated with Tovaxin. The observed regulatory immune responses have been shown to collectively correlate with clinical improvement in treated patients. Tovaxin is currently in a Phase IIb clinical trial. Patients treated in Opexa’s Phase I/II open-label studies have experienced an approximately 90% average reduction in annualized relapse rate, minimal side effects and observed improvement in average disability (EDSS) scores.

About Opexa Therapeutics

Opexa Therapeutics develops and commercializes cell therapies to treat autoimmune diseases such as MS, rheumatoid arthritis, and diabetes. The Company is focused on autologous cellular therapy applications of its proprietary T-cell and stem cell therapies. The Company’s lead product, Tovaxin®, a T-cell therapy for multiple sclerosis, is in Phase IIb trials. The Company holds the exclusive worldwide license for adult multipotent stem cells derived from mononuclear cells of peripheral blood. The technology allows large quantities of monocyte derived stem cells to be produced efficiently for use in autologous therapy, thus circumventing the threat of rejection. The Company is in preclinical development for diabetes mellitus. For more information, visit the Opexa Therapeutics website at www.opexatherapeutics.com.

Safe Harbor Statement

This press release contains "forward-looking statements," including statements about Opexa Therapeutics' growth and future operating results, discovery and development of products, strategic alliances and intellectual property, as well as other matters that are not historical facts or information. These forward-looking statements are based on management's current assumptions and expectations and involve risks, uncertainties and other important factors, specifically including those relating to Opexa Therapeutics' ability to obtain additional funding, develop its stem cell technologies, achieve its operational objectives, and obtain patent protection for its discoveries, that may cause Opexa Therapeutics' actual results to be materially different from any future results expressed or implied by such forward-looking statements. Opexa Therapeutics undertakes no obligation to update or revise any such forward-looking statements, whether as a result of new information, future events or otherwise.

Opexa Therapeutics Reports Positive Top-line Data in Phase I/II Extension Trial with Tovaxin(TM) for Multiple Sclerosis

Jun 21 2007, 9:19 AM EST

Business Wire

Opexa Therapeutics, Inc. (NASDAQ:OPXA), a company involved in the development and commercialization of cell therapies, today announced positive top-line data in an open-label Phase I/II extension clinical trial of the investigational T-cell vaccine, Tovaxin(TM), for multiple sclerosis (MS). In this one-year, 8-subject extension clinical trial of relapsing remitting (RRMS) and secondary progressive (SPMS) subjects, Tovaxin therapy was shown to be safe and effective. The "per-protocol" analysis of Tovaxin therapy achieved a 92% reduction in annualized relapse rate (ARR) in subjects who received two treatment doses of 30 - 45 x 10(6) attenuated T-cells eight weeks apart and were monitored for an additional 44 weeks. Subjects in the extension study had previously been treated an average of 5.2+/-1.8 (1, 8; median 5.4) years earlier at Baylor College of Medicine under the direction of Jingwu Zhang, M.D., Ph.D with a T-cell vaccine developed from myelin basic protein (MBP) reactive T-cells. The safety profile revealed only injection site mild reactions and no severe adverse reactions related to T-cell vaccination.

Both Phase I/II clinical studies have demonstrated that T-cell vaccination depletes myelin reactive T-cells in peripheral blood. In the extension study patient population, the myelin reactive T-cell frequencies were reduced by 84% and 72% at 6 and 12 months on study, respectively. Reductions in myelin reactive T-cell frequencies in the dose escalation study were 76.7% and 64.8% at 6 and 12 months on study, respectively.

All subjects currently are enrolled in a retreatment extension study to collect longitudinal safety and effectiveness data.

Effectiveness data for the 13 RRMS subjects across the two Phase I/II trials showed an 80% reduction in ARR. The Expanded Disability Scoring Scale (EDSS) for the RRMS subjects for a 0.5 point effect was improved, unchanged and worsened by 64.3%, 21.4% and 14.3%, respectively. The EDSS for a 0.5 point sustained (no change over 3 months) effect was improved, unchanged and worsened by 42.9%, 42.9% and 14.2%, respectively. The EDSS for a 1.0 sustained effect was improved, unchanged and worsened by 28.6%, 57.1% and 14.3%, respectively.

Brian Loftus, M.D. of Bellaire Neurology, the Principal Investigator of these Tovaxin studies, commented, "This data, combined with prior data presented on myelin reactive T-cell frequencies and ARR reductions, laid the ground work for the placebo-controlled Tovaxin IIb clinical trial (TERMS). We have shown that myelin reactive T-cells can be identified and used to produce T-cell vaccine which effectively induces the depletion of an individual's autoreactive T-cells and results in positive clinical outcomes. I anticipate Tovaxin will usher in the age of personalized therapy for MS."

David McWilliams, president and chief executive officer of Opexa, said, "We are particularly encouraged by the data from this extension trial which indicates that subjects previously treated with T-cell vaccine can be safely and effectively retreated with Tovaxin. This outcome is important to our planned extension trial for subjects currently enrolled in our TERMS trial following the one year core study time period." In addition, the effectiveness data in RRMS subjects across the two Phase I/II trials indicate strongly positive outcomes in both ARR and EDSS improvements following Tovaxin therapy."

About TERMS

The Tovaxin Phase IIb clinical study will include 150 patients in a multicenter, randomized, double blind, placebo-controlled trial designed primarily to evaluate the efficacy, safety and tolerability of the Tovaxin T-cell vaccination with clinically isolated syndrome (CIS) and relapsing-remitting MS (RR-MS) patients. A total of 100 patients will receive Tovaxin, while 50 will receive placebo. The study is designed as a two-arm, 52-week, parallel-group study, whereby patients will be given five subcutaneous injections at 0, 4, 8, 12 and 24 weeks. The analyses will be performed at the end of the 52-week study to assess the safety and efficacy of Tovaxin. The primary efficacy variable is the cumulative number of gadolinium-enhancing lesions on T1-weighted MRI scans summed over the Week 28, 36, 44, and 52 MRIs. The secondary efficacy variables are the cumulative number of new gadolinium-enhancing lesions at Weeks 28-52, the change in T2-weighted lesion volume, and the annualized relapse rate. As of May 17, 2007, Opexa announced the completion of patient enrollment in a 150-patient Phase IIb safety and efficacy study (TERMS). All patients who complete the trial will be eligible to participate in an optional one-year extension study, in which they will receive Tovaxin under an open-label protocol. The open-label study is being planned under a different protocol that will be submitted to the FDA.

The TERMS study is being conducted at 36 U.S. sites to evaluate the safety and effectiveness of Tovaxin. The TERMS study is registered on the U.S. National Institutes of Health-sponsored website, www.clinicaltrials.gov, where pharmaceutical companies are required to register trials for medicines that will treat serious or life-threatening diseases or conditions. For more information, visit the TERMS website at www.tovaxin.com.

About T-cell Vaccination

For a T-cell vaccine to be effective, it should be able to induce T-cell cytotoxic and/or regulatory immune responses against the pathogenic T-cells. Studies of T-cell vaccine have indicated that T-cell vaccination with peripheral blood-derived autologous myelin-peptide selected T-cells in multiple sclerosis patients resulted in the in vivo induction of CD8+ cytotoxic T-cells and CD4+CD25+FoxP3 Tregs specific for T-cell vaccine. The induction of anti-idiotypic cytotoxic CD8+ effector T-cells and anti-ergotypic CD4+CD25+FoxP3 positive Tregs is believed to provide a therapeutically effective dual mechanism of protection to patients treated with Tovaxin(TM). The observed regulatory immune responses have been shown to collectively correlate with clinical improvement in treated patients.

About Opexa Therapeutics

Opexa Therapeutics develops and commercializes cell therapies to treat autoimmune diseases such as MS, rheumatoid arthritis, and diabetes. The Company is focused on autologous cellular therapy applications of its proprietary T-cell and stem cell therapies. The Company's lead product, Tovaxin(TM), a T-cell therapy for multiple sclerosis is in a Phase IIb trial. The Company holds the exclusive worldwide license for adult multipotent stem cells derived from mononuclear cells of peripheral blood. The technology allows large quantities of monocyte derived stem cells to be produced efficiently for use in autologous therapy, thus circumventing the threat of rejection. The Company is in preclinical development for diabetes mellitus. For more information, visit the Opexa Therapeutics website at www.opexatherapeutics.com.

Safe Harbor Statement

This press release contains "forward-looking statements," including statements about Opexa Therapeutics' growth and future operating results, discovery and development of products, strategic alliances and intellectual property, as well as other matters that are not historical facts or information. These forward-looking statements are based on management's current assumptions and expectations and involve risks, uncertainties and other important factors, specifically including those relating to Opexa Therapeutics' ability to obtain additional funding, develop its stem cell technologies, achieve its operational objectives, and obtain patent protection for its discoveries, that may cause Opexa Therapeutics' actual results to be materially different from any future results expressed or implied by such forward-looking statements. Opexa Therapeutics undertakes no obligation to update or revise any such forward-looking statements, whether as a result of new information, future events or otherwise.

Opexa Therapeutics Completes Patient Enrollment in Phase IIb Trial of Tovaxin™ for Treatment of Multiple Sclerosis

THE WOODLANDS, Texas--(BUSINESS WIRE)--Opexa Therapeutics, Inc. (NASDAQ:OPXA), a company involved in the development and commercialization of cell therapies, today announced the completion of patient enrollment in a 150-patient Phase IIb safety and efficacy study (TERMS). The trial design is a U.S. multicenter, randomized, double-blind, placebo-controlled study of subcutaneous Tovaxin™ in subjects with Clinically Isolated Syndrome (CIS) or Relapsing/Remitting Multiple Sclerosis (RRMS).

Patients participating in the study, which is being conducted under Opexa’s U.S. Investigational New Drug (IND) application filed with the U.S. Food and Drug Administration (FDA), will receive 52 weeks of treatment and will undergo safety and efficacy assessments using primary criterion of gadolinium-enhancing lesions and secondary criterion of annualized relapse rate. The Company will collect descriptive analysis data on the first 75 subjects to reach 6 months evaluable later this year. This trial was specifically designed, with the assistance of well-known multiple sclerosis experts, to address three important objectives: to rigorously assess the safety and efficacy of Tovaxin, to maintain a robust clinical effect for the full study, and to provide a scientific and clinical database for advancement to Phase III.

David McWilliams, president and chief executive officer of Opexa Therapeutics, stated, "Full enrollment in this Phase IIb study is an important milestone in the commercialization of Tovaxin. With this milestone achieved, we now look forward to reporting a descriptive analysis in the fourth quarter of 2007 and the full data results in the second half of 2008." McWilliams continued, "I am convinced that the ability to rapidly enroll this study across 35 U.S. centers reflects the high level of interest by multiple sclerosis patients in new safe and effective treatments."

Edward Fox, MD, PhD and lead principal investigator for the Phase IIb study, commented, "If the results of this study can replicate the safety and effectiveness demonstrated in earlier studies, I believe Tovaxin could be an important advance in treating patients with MS. I’m pleased that the positive response from physicians and their MS patients across the country has resulted in the rapid enrollment of this study."

About T-cell Vaccination

For a T-cell vaccine to be effective, it should be able to induce T-cell cytotoxic and/or regulatory immune responses against the pathogenic T-cells. Studies of T-cell vaccine have indicated that T-cell vaccination with peripheral blood-derived autologous myelin-peptide selected T-cells in multiple sclerosis patients resulted in the in vivo induction of CD8+ cytotoxic T-cells and CD4+CD25+FoxP3 Tregs specific for T-cell vaccine. The induction of anti-idiotypic cytotoxic CD8+ effector T-cells and anti-ergotypic CD4+CD25+FoxP3 positive Tregs is believed to provide a therapeutically effective dual mechanism of protection to patients treated with Tovaxin™. The observed regulatory immune responses have been shown to collectively correlate with clinical improvement in treated patients.

About TERMS

The Tovaxin Phase IIb clinical study will include 150 patients in a multicenter, randomized, double blind, placebo-controlled trial designed primarily to evaluate the efficacy, safety and tolerability of the Tovaxin T Cell vaccination with clinically isolated syndrome (CIS) and relapsing-remitting MS (RR-MS) patients. A total of 100 patients will receive Tovaxin, while 50 will receive placebo. The study is designed as a two-arm, 52-week, parallel-group study, whereby patients will be given five subcutaneous injections at 0, 4, 8, 12 and 24 weeks. The analyses will be performed at the end of the 52-week study to assess the safety and efficacy of Tovaxin. The primary efficacy variable is the cumulative number of gadolinium-enhancing lesions on T1-weighted MRI scans summed over the Week 28, 36, 44, and 52 MRIs. The secondary efficacy variables are the cumulative number of new gadolinium-enhancing lesions at Weeks 28-52, the change in T2-weighted lesion volume, and the annualized relapse rate.

All patients who complete the trial will be eligible to participate in an optional one-year extension study, in which they will receive Tovaxin under an open-label protocol. The open-label study is being planned under a different protocol that will be submitted to the FDA.

About Opexa Therapeutics

Opexa Therapeutics develops and commercializes cell therapies to treat autoimmune diseases such as MS, rheumatoid arthritis, and diabetes. The Company is focused on autologous cellular therapy applications of its proprietary T-cell and stem cell therapies. The Company's lead product, Tovaxin(TM), a T-cell therapy for multiple sclerosis is in Phase IIb trials. The Company holds the exclusive worldwide license for adult multipotent stem cells derived from mononuclear cells of peripheral blood. The technology allows large quantities of monocyte derived stem cells to be produced efficiently for use in autologous therapy, thus circumventing the threat of rejection. The Company is in preclinical development for diabetes mellitus. For more information, visit the Opexa Therapeutics website at www.opexatherapeutics.com.

Safe Harbor Statement

This press release contains "forward-looking statements," including statements about Opexa Therapeutics' growth and future operating results, discovery and development of products, strategic alliances and intellectual property, as well as other matters that are not historical facts or information. These forward-looking statements are based on management's current assumptions and expectations and involve risks, uncertainties and other important factors, specifically including those relating to Opexa Therapeutics' ability to obtain additional funding, develop its stem cell technologies, achieve its operational objectives, and obtain patent protection for its discoveries, that may cause Opexa Therapeutics' actual results to be materially different from any future results expressed or implied by such forward-looking statements. Opexa Therapeutics undertakes no obligation to update or revise any such forward-looking statements, whether as a result of new information, future events or otherwise.

Opexa Therapeutics Reports Positive Top-line Data in Phase I/II Dose Escalation Trial with TovaxinTM for Multiple Sclerosis

Opexa Therapeutics Reports Positive Top-line Data in Phase I/II Dose Escalation Trial with TovaxinTM for Multiple Sclerosis

THE WOODLANDS, Texas--(BUSINESS WIRE)--Opexa Therapeutics, Inc. (NASDAQ: OPXA), a company involved in the development and commercialization of cell therapies, today announced positive top-line data in an open-label Phase I/II dose escalation clinical trial of the investigational T-cell vaccine, Tovaxin™, for multiple sclerosis. In this one-year, 10-subject dose escalation clinical trial, Tovaxin therapy was shown to be safe and effective. The “per-protocol” analysis of Tovaxin therapy achieved a 90% reduction (p = 0.0039) in annualized relapse rate (ARR) in subjects who received one of the three dosage levels; the doses were 6 – 9 x 106, 30 – 45 x 106 or 60 – 90 x 106 attenuated T-cells. Subjects in the study received subcutaneous injections of Tovaxin over a period of 20 weeks (0, 4, 12 and 20 weeks) and were monitored for an additional 32 weeks.

The safety profile for all dosage levels revealed no severe adverse reactions related to T-cell vaccination. With increasing dosage, an increase in mild injection site reactions was observed and these resolved within 48 hours.

All subjects currently are enrolled in an extension study to collect longitudinal safety and effectiveness data.

David McWilliams, president and chief executive officer of Opexa, commented, “We are particularly encouraged by the data from this dose escalation trial. While all three dosage levels were safe and effective, the group treated with the 30 – 45 x 106 T-cell dose achieved a 100% reduction in ARR. The currently enrolling Tovaxin IIb clinical trial is being conducted with the 30 – 45 x 106 T-cell dose.”

About TERMS

The Tovaxin Phase IIb clinical study will include 150 patients in a multicenter, randomized, double blind, placebo-controlled trial designed primarily to evaluate the efficacy, safety and tolerability of the Tovaxin T- cell vaccination with clinically isolated syndrome (CIS) and relapsing-remitting MS (RR-MS) patients. A total of 100 patients will receive Tovaxin, while 50 will receive placebo. The study is designed as a two-arm, 52-week, parallel-group study, whereby patients will be given five subcutaneous injections at 0, 4, 8, 12 and 24 weeks. The analyses will be performed at the end of the 52-week study to assess the safety and efficacy of Tovaxin. The primary efficacy variable is the cumulative number of gadolinium-enhancing lesions on T1-weighted MRI scans summed over the Week 28, 36, 44, and 52 MRIs. The secondary efficacy variables are the cumulative number of new gadolinium-enhancing lesions at Weeks 28-52, the change in T2-weighted lesion volume, and the annualized relapse rate. As of March 19, 2007, Opexa reported that more than 110 patients have been enrolled in the TERMS clinical trial and the Company expects enrollment to be complete by mid 2007.

All patients who complete the trial will be eligible to participate in an optional one-year extension study, in which they will receive Tovaxin under an open-label protocol. The open-label study is being planned under a different protocol that will be submitted to the FDA.

The TERMS study is being conducted at 36 U.S. sites to evaluate the safety and effectiveness of Tovaxin It is registered on the U.S. National Institutes of Health-sponsored website, www.clinicaltrials.gov, where pharmaceutical companies are required to register trials for medicines that will treat serious or life-threatening diseases or conditions. For more information, visit the TERMS website at www.tovaxin.com.

About T-cell Vaccination

For a T-cell vaccine to be effective, it should be able to induce T-cell cytotoxic and/or regulatory immune responses against the pathogenic T-cells. Studies of T-cell vaccine have indicated that T-cell vaccination with peripheral blood-derived autologous myelin-peptide selected T-cells in multiple sclerosis patients resulted in the in vivo induction of CD8+ cytotoxic T-cells and CD4+CD25+FoxP3 Tregs specific for T-cell vaccine. The induction of anti-idiotypic cytotoxic CD8+ effector T-cells and anti-ergotypic CD4+CD25+FoxP3 positive Tregs is believed to provide a therapeutically effective dual mechanism of protection to patients treated with Tovaxin™. The observed regulatory immune responses have been shown to collectively correlate with clinical improvement in treated patients.

About Opexa Therapeutics

Opexa Therapeutics develops and commercializes cell therapies to treat autoimmune diseases such as MS, rheumatoid arthritis, and diabetes. The Company is focused on autologous cellular therapy applications of its proprietary T-cell and stem cell therapies. The Company's lead product, Tovaxin(TM), a T-cell therapy for multiple sclerosis is in Phase IIb trials. The Company holds the exclusive worldwide license for adult multipotent stem cells derived from mononuclear cells of peripheral blood. The technology allows large quantities of monocyte derived stem cells to be produced efficiently for use in autologous therapy, thus circumventing the threat of rejection. The Company is in preclinical development for diabetes mellitus. For more information, visit the Opexa Therapeutics website at www.opexatherapeutics.com.

Safe Harbor Statement

This press release contains "forward-looking statements," including statements about Opexa Therapeutics' growth and future operating results, discovery and development of products, strategic alliances and intellectual property, as well as other matters that are not historical facts or information. These forward-looking statements are based on management's current assumptions and expectations and involve risks, uncertainties and other important factors, specifically including those relating to Opexa Therapeutics' ability to obtain additional funding, develop its stem cell technologies, achieve its operational objectives, and obtain patent protection for its discoveries, that may cause Opexa Therapeutics' actual results to be materially different from any future results expressed or implied by such forward-looking statements. Opexa Therapeutics undertakes no obligation to update or revise any such forward-looking statements, whether as a result of new information, future events or otherwise.

Editor's Note:

In first and fourth paragraphs of this release, T-cell dosage levels include the figure 10(6), which should be read as ten to the sixth power.

Opexa Therapeutics to Be Featured in Live MN1.com Interview

Mar 19 2007, 6:30 AM EST

Business Wire

Opexa Therapeutics, Inc. (NASDAQ:OPXA), a company involved in the development and commercialization of cell therapies, announced that its chief executive officer, David McWilliams, will be featured in a live Market News First interview on Tuesday, March 20, 2007 at 9:30 am Central Time. The interview can be heard live on Market News First's website at www.mn1.com.

The interview will also be available in a podcast which can be downloaded from the Market News First website within 48 hours of the interview.

Mr. McWilliams will discuss the Company's ongoing clinical trials for its novel therapeutic, Tovaxin(TM), for multiple sclerosis as well as the innovative therapies the Company is developing to treat rheumatoid arthritis and diabetes.

About Opexa Therapeutics

Opexa Therapeutics develops and commercializes cell therapies to treat autoimmune diseases such as MS, rheumatoid arthritis, and diabetes. The Company is focused on autologous cellular therapy applications of its proprietary T-cell and stem cell therapies. The Company's lead product, Tovaxin(TM), a T-cell therapy for multiple sclerosis is in Phase IIb trials. The Company holds the exclusive worldwide license for adult multipotent stem cells derived from mononuclear cells of peripheral blood. The technology allows large quantities of monocyte derived stem cells to be produced efficiently for use in autologous therapy, thus circumventing the threat of rejection. The Company is in preclinical development for diabetes mellitus.

About MN1.com

Market News First is an online, market news provider that brings investors current news on the market. Market News First is the only online, live radio web site that brings real market news to investors and features live interaction with companies from the Bulletin Board to NYSE.

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Safe Harbor Statement

This press release contains "forward-looking statements," including statements about Opexa Therapeutics' growth and future operating results, discovery and development of products, strategic alliances and intellectual property, as well as other matters that are not historical facts or information. These forward-looking statements are based on management's current assumptions and expectations and involve risks, uncertainties and other important factors, specifically including those relating to Opexa Therapeutics' ability to obtain additional funding, develop its stem cell technologies, achieve its operational objectives, and obtain patent protection for its discoveries, that may cause Opexa Therapeutics' actual results to be materially different from any future results expressed or implied by such forward-looking statements. Opexa Therapeutics undertakes no obligation to update or revise any such forward-looking statements, whether as a result of new information, future events or otherwise.