Results From Phase 1 Influenza Vaccine Clinical Trial Promising

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Phase 1 Influenza Vaccine Clinical Trial

AlphaVax announced results from an interim review of the data from a Phase I clinical trial of an influenza vaccine that is based on its platform replicon vector technology.

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The trial is a placebo-controlled, randomized, double-blind, single center study involving 216 healthy volunteers (18-40 years of age). The data are from the analysis of samples taken four weeks after a single dose of the vaccine was administered -- at one of two dosage levels. To date, the vaccine has proven to be safe and very well tolerated. Among those individuals who had pre-vaccination influenza serum antibody titers (measured by hemagglutination inhibition, or "HI") that were below levels deemed protective against influenza infection, 77% of those receiving a low dose of the vaccine, and 80% of the individuals receiving a higher dose, demonstrated protective HI serum antibody titers after a single dose of the influenza vaccine. These results are irrespective of the route of administration used.

"We are pleased with the overall performance of our vaccine following a single dose in non-prescreened individuals, particularly noting that many had detectable antibody titers prior to enrolling in the trial that are known to suppress responses to vaccines," said Dr. Robert A. Olmsted, Vice President for Research.

The vaccine used in this trial contains a replicon vector, derived from an attenuated alphavirus that expresses the hemagglutinin ("HA") gene from the A/Wyoming H3N2 strain of influenza virus. Virus-like particles containing the replicon vectors are produced in cell culture, unlike currently marketed influenza vaccines that are produced in chicken eggs. A key design and safety feature of this system is that, after initial expression of the influenza HA protein in vaccine recipients which induces the immune response, there is no further replication of the vaccine particles.

AlphaVax is, additionally, evaluating the capability of its platform technology in clinical trials evaluating vaccines for cytomegalovirus (CMV) and colon cancer, with initial results from the former expected later this year. A clinical trial for a pandemic influenza vaccine is also scheduled to begin in late 2007, and the design of that study "will be based on the positive results from the current seasonal influenza vaccine trial," said Olmsted. In addition, newly discovered adjuvant technologies, which are based on the same replicon vector platform and are the subject of a recently awarded $3.6 million grant to AlphaVax from the National Institutes of Health (NIH), have the potential to "enhance the response to this influenza vaccine as well as the other vaccines under development," said Dr. Jonathan F. Smith, Chief Scientific Officer.

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