Tcelna
Tovaxin is a novel anti-T-cell therapeutic vaccine that parallels the concept of autologous cancer vaccines. Instead of modifying cancerous cells, TovaxinTM consists of attenuated autoreactive T cells. Tovaxin is being developed by Opexa Therapeutics in Houston, Texas
Method of Action
Tovaxin takes a patient's own T-cells from a blood sample drawn in the clinic. Attenuation of the patient's T-cells during the vaccine production process renders the cells non-replicating but viable and causes them to elicit an immune response when injected subcutaneously (under the skin) into the patient. This immune response is directed against T-cells within the patient that are self-reactive with myelin. Myelin is the sheath that covers the neurons that are affected in Multiple Sclerosis. This immune response, directed against a specific subset of autoreactive T cells, greatly reduces the number of these autoreactive cells in MS patients.
During the latest study, treatment has consisted of four injections spaced four weeks apart followed by one injection at 24 weeks. Biannual booster shots will follow. Only minimal side effects have resulted from the use of the treatment — these consisting of mild injection site reactions, typically clearing within a day.
As with any other disease modifying therapy, Tovaxin attacks the underlying cause of MS rather than just addressing its symptoms.
Status of FDA Trials
In October 2005, the Company presented positive interim research findings of its Phase I/II clinical trials of Tovaxin at the 21st European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) and the 10th Americas Committee for Treatment and Research in Multiple Sclerosis (ACTRIMS) congress held in Thessaloniki, Greece. The trial results indicated that the treatment appeared safe and well tolerated with no dose-limiting toxicities, and that Tovaxin depletes the myelin-peptide reactive T cells that may contribute to the Multiple Sclerosis (MS) disease processes.
PharmaFrontiers, currently named Opexa Therapeutics, announced in late 2005 that the U.S. Food and Drug Administration's Center for Biologics Evaluation and Research (FDA's CBER) had approved the protocol for its Phase IIb clinical trial of Tovaxin. PharmaFrontiers conducted Phase IIb with its clinical development partner, INC Research, Raleigh, North Carolina.
That multicenter, randomized, double blind, placebo-controlled Phase IIb clinical study was designed primarily to evaluate the efficacy, safety and tolerability of the Tovaxin T Cell therapy with clinically isolated syndrome (CIS) and early relapsing-remitting MS (RR-MS) patients. Additionally, the study of these patients will evaluate biomarkers of Tovaxin's efficacy and to evaluate the effect of Tovaxin on immune deviation and epitope spreading.
The clinical trial finished in March 2008[1]. All patients who completed the trial were to be eligible to participate in an optional one-year extension study, OLTERMS, in which they were to receive Tovaxin open-label—without a placebo group; however, OLTERMS was terminated suddenly in order to conserve funding and seek a financial partner.[2]
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