BALTIMORE, April 28, 2009 (GLOBE NEWSWIRE) -- Vical Incorporated (Nasdaq:VICL) today announced that the company's Vice President of Vaccine Research, Larry R. Smith, Ph.D., is presenting updates on the company's pandemic influenza and cytomegalovirus (CMV) vaccine programs at the 12th Annual Conference on Vaccine Research sponsored by the National Foundation for Infectious Diseases (Baltimore, April 27 - 29).
Pandemic Influenza Vaccine
"Phase 1 Safety and Immunogenicity Results of Vaxfectin(r)-formulated Plasmid DNA Vaccines Encoding Influenza Virus H5 Hemaggluntinin," an oral presentation, summarizes results from the company's successful Phase 1 trial and future goals for its pandemic influenza DNA vaccine program. The double-blind, placebo-controlled, dose-escalation Phase 1 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 vaccination, and to evaluate monovalent and trivalent Vaxfectin(r)-formulated H5N1 pandemic influenza DNA vaccines at various doses. The vaccines were safe and well tolerated in the trial, and induced antibody responses and T-cell responses against a matching strain of influenza virus, and cross-clade antibody responses against different strains.
The current public health emergency caused by outbreaks of H1N1 swine influenza highlights the need for a faster method to develop and produce vaccines. Vical's technology could produce a vaccine within six to nine weeks after the H1 hemagglutinin gene is sequenced. If the U.S. government or an international health agency issues a directive and provides the necessary resources, Vical is prepared to respond. In its broader pandemic influenza effort, Vical is currently exploring potential sources of funding for further development. The company's near-term goals are to confirm vaccine safety and immunogenicity in a larger number of subjects, optimize vaccine dose and adjuvant ratio, explore prime-boost regimens with different vaccines, and leverage the Phase 1 proof of concept for its DNA vaccine platform and Vaxfectin(r) adjuvant into additional indications.
CMV
CMV is a herpes virus that infects more than half of all adults in the United States by age 40, and is even more widespread in developing countries. While a healthy immune system typically protects an infected person against CMV disease, it rarely succeeds in eliminating the infection, and those whose immune systems are not fully functional are at high risk of CMV reactivation, potentially leading to severe illness or death. Those at greatest risk include transplant patients and infants born to mothers who first become infected during pregnancy. Vical is pursuing two different vaccine approaches for these distinct market segments.
TransVax(tm) Therapeutic CMV Vaccine
For transplant patients, Vical is developing TransVax(tm), a therapeutic, poloxamer-formulated DNA vaccine encoding the CMV the phosphoprotein 65 (pp65) antigen, designed to induce primarily a cellular immune response, and glycoprotein B (gB) antigen, designed to induce primarily an antibody response. Vical's TransVax(tm) vaccine cannot cause CMV disease, and has orphan drug designation for transplant patients.
"Preliminary Phase 2 Immunogenicity Results of a CMV DNA Vaccine in Hematopoietic Cell Transplant Recipients," also an oral presentation at the NFID conference, summarizes results of an interim immunogenicity analysis for a subset of hematopoeitic stem cell (bone marrow) transplant recipients in the Phase 2 trial of Vical's TransVax(tm) vaccine. An interim analysis of immunogenicity data for the first group enrolled in the recipient-only arm of the study showed significant (p<0.05) post-transplant enhancement of CMV-specific T-cell responses in subjects receiving vaccine compared with subjects receiving placebo. The company expects to report clinical efficacy results in the second quarter of 2009.
CMV affects 30% to 60% of patients undergoing transplant procedures, causing transplant rejection, serious illness and even death if untreated. Expensive and toxic antiviral drug therapy is used to control the disease, but does not eliminate the infection. There is no approved vaccine against CMV. Protein-based vaccines that predominantly result in antibody responses to CMV have not proven highly effective in transplant patients. Live, attenuated vaccines can induce both antibody and cellular immune responses, but pose a potential safety concern, particularly for immunocompromised patients, of causing the disease they are intended to prevent.
CyMVectin(tm) Prophylactic CMV Vaccine
To prevent infection of adolescent females, Vical is developing CyMVectin(tm), a prophylactic DNA vaccine encoding the gB antigen, one of the two antigens currently used in the TransVax(tm) vaccine. The company intends to formulate CyMVectin(tm) with its Vaxfectin(r) adjuvant in order to enhance antibody and T-cell responses to gB. In a recently completed Phase 1 trial, the company's Vaxfectin(r)-formulated H5N1 pandemic influenza vaccine induced both antibody and T-cell responses against the encoded H5 hemagglutinin. Vical is actively evaluating collaborative opportunities for this vaccine and is currently developing an appropriate clinical trial design.
Mothers who are infected with CMV during pregnancy, especially during the first trimester, can transmit the virus to the fetus, where it affects the development of the central nervous system. CMV is the most common intrauterine infection of fetuses and congenital CMV is the leading infectious disease cause of birth defects in the United States, similar to rubella in the '40s and '50s before an effective vaccine was available. Congenital CMV infection affects one out of every hundred infants, and causes severe consequences in about 3,600 infants and death in about 400 each year in the United States. Infants born with CMV infection can be affected by blindness, deafness and mental retardation and these consequences are frequently undiagnosed until the child reaches several years of age. Widespread vaccination of adolescent females has the potential to significantly reduce or even eliminate congenital CMV over time, and this market segment offers a significant commercial vaccine target. The successful launch of a vaccine for the prevention of human papillomavirus (HPV), a primary cause of cervical cancer, has demonstrated the size and receptivity of the adolescent female vaccine market.
About Vical
Vical researches and develops biopharmaceutical products based on its patented DNA delivery technologies for the prevention and treatment of serious or life-threatening diseases. Potential applications of the company's DNA delivery technology include DNA vaccines for infectious diseases or cancer, in which the expressed protein is an immunogen; cancer immunotherapeutics, in which the expressed protein is an immune system stimulant; and cardiovascular therapies, in which the expressed protein is an angiogenic growth factor. The company is developing certain infectious disease vaccines and cancer therapeutics internally. In addition, the company collaborates with major pharmaceutical companies and biotechnology companies that give it access to complementary technologies or greater resources. These strategic partnerships provide the company with mutually beneficial opportunities to expand its product pipeline and address significant unmet medical needs. Additional information on Vical is available at www.vical.com.
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This press release contains forward-looking statements subject to risks and uncertainties that could cause actual results to differ materially from those projected. Forward-looking statements include statements about the company's TransVax(tm) Phase 2 clinical trial, the company's Vaxfectin(r)-formulated H5N1 influenza vaccine Phase 1 clinical trial, and potential future directions for the TransVax(tm), CyMVectin(tm) and H5N1 influenza vaccine programs, and the potential to apply Vical's technology to development of a vaccine against H1N1 swine influenza. Risks and uncertainties include whether Vical or others will continue development of TransVax(tm), CyMVectin(tm), or the H5N1 pandemic influenza vaccine, or pursue development of a vaccine against H1N1 swine influenza or any other vaccines; whether the U.S. government or international health agencies will issue a directive or provide resources to Vical for development of a vaccine against H1N1 swine influenza; whether such vaccine will be developed rapidly and produced within six to nine weeks after sequencing of the H1 hemagglutinin gene, if at all; whether such vaccine, if produced, would be effective in providing protection against H1N1 swine influenza, and if so, whether it would be deployed; whether TransVax(tm) will achieve the safety and efficacy endpoints in the Phase 2 trial; whether T-cell responses will limit levels of active CMV or reduce CMV disease; whether the interim evaluation of immunogenicity in the Phase 2 trial will be predictive of clinical benefit, and if so, whether such benefit will be confirmed with clinical efficacy results in the second quarter of 2009, if at all; whether reported clinical trial results will be confirmed in larger studies; whether the company's H5N1 influenza DNA vaccine will provide durable protection or protect against emerging strains that do not match the vaccine; whether T-cell responses will provide broader protection than antibodies alone; whether vaccines against CMV, H5N1 influenza, or any other targets will be successfully developed and commercialized; whether Vical or its collaborative partners will seek or gain approval to market TransVax(tm), CyMVectin(tm), the pandemic influenza vaccine or any other product candidates; whether Vical or its collaborative partners will succeed in marketing any product candidates; whether Vical or others will secure funding to advance the CMV or H5N1 influenza vaccine programs; whether any product candidates will be shown to be safe and efficacious in clinical trials; the timing of clinical trials; whether Vical or its collaborative partners will seek or gain approval to market any product candidates; and additional risks set forth in the company's filings with the Securities and Exchange Commission. These forward-looking statements represent the company's judgment as of the date of this release. The company disclaims, however, any intent or obligation to update these forward-looking statements.