T-cell vaccination technology for the treatment of multiple sclerosis.

 

THE WOODLANDS, Texas, USA—

 

Opexa Therapeutics, Inc.  (NASDAQ:OPXA), a company involved in the development and  commercialization of cell therapies, made a poster presentation at  the 2007 Annual Meeting of the Federation of Clinical Immunology 

The presentation covered laboratory and clinical data from the 
Company’s proprietary T-cell vaccination technology for the 
treatment of multiple sclerosis. Key highlights of research detailed 
in the poster presentation include:

     * Data accumulated from over 173 assays (using a T-cell Epitope 
Analysis Assay (EAA)) have allowed Opexa to identify several myelin 
protein peptides from myelin basic protein (MBP), myelin proteolipid 
protein (PLP) and myelin oligodendrocyte glycoprotein (MOG) as being 
immunodominant, including some peptides never before reported, and 
others as being non-reactive,
     * The EAA can be utilized to screen additional or combinations 
of peptides that have biological significance and;
     * These results have permitted Opexa to optimize the number of 
myelin peptides across the lengths of MBP, PLP and MOG in the 
screening assay for Tovaxin™ vaccine production to qualify subjects 
for Opexa’s current 150-patient Phase IIb safety and efficacy 
clinical trial (TERMS).

“These findings mark an important development for Tovaxin, which is 
a patient-specific autologous T-cell vaccine, because it helps us 
qualify subjects for our current clinical trial and improves 
production of the vaccine. The EAA is an important assay for further 
refinement of the T-cell vaccination technology, which is truly 
personalized, to make the therapy as efficacious as possible for each 
patient,” said Jim Williams, PhD, chief operating officer.

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 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, 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.