Immune Response BioPharma, Inc.'s proprietary technology seeks to identify these unique T cell receptor proteins and determine their peptide sequence. These peptides can then be artificially synthesized and used to vaccinate the patient. The Company believes that by vaccinating with T cell receptor peptides specific to the autoreactive T cells, the therapy may induce the immune system to down-regulate turn off the aberrant T cells without affecting other normal cells. Vaccination holds the appeal of not only providing a specific therapy without global immunosuppression, but also utilizing normal pathways of immune system self regulation.
Rationale: The observation of elevated expression and clonality of certain T cell receptors (TCR) in the rheumatoid synovium has led to clinical trials of TCR peptide vaccines for the treatment of rheumatoid arthritis (RA). IR501 Therapeutic Vaccine (IR501) consists of a combination of three, 17-20 amino acid peptides derived from TCRs (Vb17, Vb14 and Vb3) emulsified in incomplete Freunds adjuvant (IFA). A prior phase II study of IR501 in RA ) has shown it to be safe, well tolerated and effective. IR703 Therapeutic Vaccine (IR703) consists of three, 40 amino acid peptides which encompass the IR501 peptides. We report here the results of a double-blind placebo controlled phase IIb trial of IR501 and IR703 Therapeutic Vaccines in RA.
Methods: 340 patients with active RA were randomly assigned to five treatment groups: IR501: 30 mg; 90 mg; IR703: 30 mg; 90 mg; or IFA control. IM injections were given at weeks 0, 4, 8 and 20. Patients were assessed monthly for 24 weeks.
Results: Using ACR ³ 20% criteria, a statistically significant clinical response was found in the IR501 30 mg group compared with placebo (34% vs 18%, p< 0.05) at 16 weeks. The IR501 90 mg and IR703 90 mg groups also demonstrated significant improvement but did not reach statistical significance. Patients receiving 7.5 mg prednisone daily showed greater treatment effect. Patients with disease duration 3 years treated with IR501 30 mg and IR703 90 mg showed a statistically significant treatment effect at endpoint (50%, 50% vs 8%). In all but the IFA and IR703 30 mg treatment groups, improvement was seen after the initial 3 injections, but waned by week 20. In the IR501 30 mg and IR703 90 mg groups, dosing at week 20 boosted the clinical response.
Conclusions: These data suggest that IR501 and IR703 are safe, well tolerated and effective treatments for RA, particularly in early disease and in patients on physiologic low doses of prednisone. Enhancement of the clinical response may require monthly injections. These observations require confirmation in future clinical trials.
The double-blind trial enrolled 340 patients who received either 30 > micrograms (n=67) or 90 micrograms (n=68) of IR501 Therapeutic Vaccine or 30 micrograms (n=73) or 90 micrograms (n=66) of IR703 Therapeutic Vaccine or adjuvant alone (n=65) as a control. Treatments were administered as a single 1.0 mL intramuscular injection at Weeks 0, 4, 8, and 20, and patients were followed for 24 weeks. The results of the trial suggest that the treatment may be safe and well > tolerated. Patients receiving both doses of IR501 and the higher dose of IR703 appeared to have clinically meaningful improvement in their disease condition after three injections. A statistically significant (p patients with improvement in their disease condition was observed after the third injection of IR501 Therapeutic Vaccine using the ACR 20 criteria for improvement.
"The RAVAX investigational therapeutic vaccine is designed to treat the causes of RA disease and relieve the disease symptoms. What we have learned from reviewing the data is that monthly injections for at-least 12 months will be optimal for patients and the addition of Methotrexate as we plan for our new Phase III study will be important initiatives to move the RAVAX RA vaccine to the finish line and FDA approval. We are currently and actively seeking a corporate partner for this wonderful treatment for RA that we believe can be a safe alternative to current treatments for patients who fail Humira or Enbrel & can become treatment of choice for RA patients diagnosed with under 10 years of RA" Mr. David Buswell CEO IRBP.
Immune Response BioPharma, Inc. maybe found on the World WideWeb at www.immuneresponsebiopharma.com or our shorter URL @ www.immuneresponse.net
