SARS Vaccine Achieves Neutralizing Responses in First U.S. Human Trial
The DNA vaccine was developed by the Vaccine Research Center (VRC),National Institute of Allergy and Infectious Diseases (NIAID), NIH, andmanufactured by Vical. Three doses of 4 mg each were delivered on Days 0, 28and 56 with the Biojector(R) 2000 needle-free injection system (BiojectMedical Technologies Inc., OTC Bulletin Board: BJCT). In the article, authorsfrom the VRC detailed safety and immunogenicity results, and concluded, "Thisvaccine also demonstrates the feasibility of rapid manufacturing andregulatory review and provides additional safety and immunogenicity data tosupport the concept of DNA vaccination as a potential vaccine platform forfuture emerging infectious diseases."
After completion of the NIH Phase I clinical trial, NIAID transferred theInvestigational New Drug application (IND) for the vaccine to Vical, and thecompany has evaluated its options to continue development of the vaccine whena medical need arises. "Like many emerging infectious diseases, SARS issuspected of having origins in an animal reservoir and is therefore likely tore-emerge at some point in the future," said Vijay Samant, Vical's Presidentand Chief Executive Officer. "With the data from this successful Phase I trialand control of the IND, we are prepared to advance this vaccine quickly in theevent of another outbreak. In the meantime, we can look to the modelestablished with this program in addressing other emerging infectiousdiseases."
Side effects in the Phase I trial were typically mild, and no seriousadverse events were reported. SARS-specific neutralizing antibody responseswere detected in 8 of 10 subjects. SARS-specific CD4+ T-cell responses weredetected in all 10 subjects, and CD8+ T-cell responses were detected in 2 of10 subjects. Neutralizing antibody responses are important in preventinginfection. CD4+ T cells help direct the appropriate immune resources againstspecific pathogens. CD8+ T cells find and kill infected cells and areimportant in clearing virus after infection.
Following the initial cases of SARS, identified in the Guangdong Provinceof China in late 2002, the disease spread rapidly through the summer of 2003and reached epidemic status, affecting more than 8,000 and killed more than900 people in 25 countries before it was contained. SARS affects therespiratory system and gastrointestinal tract as well as other internalorgans, with particular risk to the elderly and immunocompromised. Healthyadults may become infected and spread the disease without exhibiting anysymptoms.
About DNA Vaccines
DNA vaccines may offer both technical and economic advantages comparedwith conventional vaccine approaches. DNA vaccines encode certain proteinsassociated with a target pathogen, rather than using any part of the pathogenitself, and can prime the immune system as well as induce antibody and T-cellimmune responses. DNA vaccines contain no viral particles, are non-infectious,and can be administered on a repeat basis without unwanted immune responses.Additionally, DNA vaccines have the potential to achieve proof of concept morequickly and cost-effectively than conventional vaccines, and can bemanufactured using uniform methods of fermentation and purification, allowingsignificantly faster development and production.
Vical researches and develops biopharmaceutical products based on itspatented DNA delivery technologies for the prevention and treatment of seriousor life-threatening diseases. Potential applications of the company's DNAdelivery technology include DNA vaccines for infectious diseases or cancer, inwhich the expressed protein is an immunogen; cancer immunotherapeutics, inwhich the expressed protein is an immune system stimulant; and cardiovasculartherapies, in which the expressed protein is an angiogenic growth factor. Thecompany is developing certain infectious disease vaccines and cancertherapeutics internally. In addition, the company collaborates with majorpharmaceutical companies and biotechnology companies that give it access tocomplementary technologies or greater resources. These strategic partnershipsprovide the company with mutually beneficial opportunities to expand itsproduct pipeline and address significant unmet medical needs. Additionalinformation on Vical is available at http://www.vical.com.
This press release contains forward-looking statements subject to risksand uncertainties that could cause actual results to differ materially fromthose projected, including: whether Vical or others will continue developmentof the SARS DNA vaccine; whether SARS will re-emerge, and if so, whether theDNA vaccine will be effective in protecting against SARS infection or disease;whether DNA vaccines will be successfully developed for other emerginginfectious diseases; whether the SARS vaccine or any other product candidateswill be shown to be safe and effective in clinical trials; the timing, natureand cost of clinical trials; the availability of future funding to support thecost of continued development; whether Vical or its collaborative partnerswill seek or gain approval to market the measles vaccine or any other productcandidates; whether Vical or its collaborative partners will succeed inmarketing the SARS vaccine or any other product candidates; and additionalrisks set forth in the company's filings with the Securities and ExchangeCommission. These forward-looking statements represent the company's judgmentas of the date of this release. The company disclaims, however, any intent orobligation to update these forward-looking statements.
(1) Martin JE et al. A SARS DNA vaccine induces neutralizing antibody andcellular immune responses in healthy adults in a Phase I clinical trial.Vaccine. 2008 Nov 25;26(50):6338-6343.
Contact: Alan R. Engbring(858) 646-1127 Website: http://www.vical.com
SOURCE Vical Incorporated
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