Vical Announces Breakthrough for Pandemic Influenza DNA Vaccines with Preliminary Human Data
News Jul 17, 2008
Vical Incorporated has announced a breakthrough with preliminary clinical trial data demonstrating that DNA vaccines can safely achieve significant immune responses against H5N1 pandemic influenza in humans.
DNA vaccines are fundamentally different from conventional vaccines because they do not contain any part of the virus itself, and may offer compelling advantages in response to a pandemic outbreak because of significantly reduced development and manufacturing times.
Specifically, preliminary human safety and immunogenicity data obtained in a 100-subject Phase 1 trial of the company's Vaxfectin®-formulated H5N1 pandemic influenza DNA vaccines demonstrated for the first time that DNA vaccines have achieved potentially protective levels of antibody responses in up to 67% of evaluable subjects in the higher dose cohorts.
No significant safety issues were observed at any of the Vical vaccine doses tested. These results support further development of Vaxfectin®-formulated DNA vaccines, and could position them as potential alternatives to conventional vaccines.
"The preliminary results from this Phase 1 trial indicate for the first time that an adjuvanted DNA vaccination against H5N1 influenza is well-tolerated and can induce impressive antibody responses even against this relatively weak immunogen," said Robert B. Belshe, M.D., Dianna and J. Joseph Adorjan Endowed Professor of Infectious Diseases and Immunology, Saint Louis University School of Medicine, who was the lead external safety monitor for the study.
"Successful development of a safe and effective DNA vaccine will help address the potential public health threat of pandemic influenza."
Vijay B. Samant, Vical's President and Chief Executive Officer, said, "Our preliminary Phase 1 pandemic influenza vaccine results clearly demonstrate the potential of Vaxfectin®-formulated DNA vaccines to achieve antibody responses in the same range as conventional vaccines. The ability to manufacture DNA vaccines in weeks rather than the months required for conventional vaccines may provide a significant advantage when dealing with an emerging infectious disease such as pandemic influenza. This trial is also important because it marks the first successful safety evaluation in humans for our Vaxfectin® adjuvant, which has potential applications with both DNA vaccines and conventional protein-based vaccines."
The double-blind, placebo-controlled, dose-escalation trial was conducted in approximately 100 healthy volunteers age 18 to 45 at three U.S. clinical sites. The trial was designed to assess safety and immunogenicity following intramuscular vaccination with needle and syringe or with the Biojector® 2000 needle-free injection system in different cohorts, and to evaluate monovalent and trivalent Vaxfectin®-formulated DNA vaccines at various doses.