ANNAPOLIS, Md., April 28 /PRNewswire/ -- PharmAthene, Inc. , a biodefense company developing medical countermeasures against biological and chemical threats, announced today that results from a second Phase II study of SparVax(TM) were presented yesterday at the 12th Annual Conference on Vaccine Research, being held in Baltimore, MD, April 27-29, 2009. The conference is sponsored by the National Foundation of Infectious Diseases.
David P. Wright, President and Chief Executive Officer of PharmAthene commented, “We are very pleased to have had the opportunity to present these latest data for SparVax(TM) at Annual Conference on Vaccine Research. The study, which compared our vaccine to the currently licensed anthrax vaccine, BioThrax(R), provides further confirmation that SparVax(TM) is immunogenic and promotes good immunological recall following antigenic challenge. In addition, a lower incidence of injection site reactions observed with SparVax(TM) may suggest that it is better tolerated than BioThrax(R), a very important finding for this product candidate. Presentation of these data to attendees at this conference allows PharmAthene to continue to increase awareness of the progress we are making developing improved products using modern vaccine technologies to protect our Nation’s citizens and military.”
SparVax(TM) is a novel second generation recombinant protective antigen (rPA) anthrax vaccine that is being developed for pre and post exposure protection against anthrax infection.
SparVax(TM) Phase II Clinical Data
Results from a Phase II clinical trial of SparVax(TM) were presented during a poster session by Dr. Matthew Duchars, Chief Scientific Officer for PharmAthene.
The study was one of two Phase II trials evaluating different dose and dosing regimens of SparVax(TM). The objective of the Phase II study was to evaluate safety, tolerability and immunogenicity of SparVax(TM) and to compare it to the licensed vaccine, BioThrax(R), which was administered in accordance with the then approved vaccination route and regimen for general use in prophylaxis against anthrax. A total of 226 healthy male and female volunteers, age 18-55, were enrolled in the trial which was conducted at 16 sites in the United States.
The subjects were randomized to receive either three doses of BioThrax(R) or SparVax(TM) (at one of two dose levels followed by an antigenic challenge dose, i.e., a dose to show that the initial series of doses adequately “primed” the immune system to respond to natural infection by producing antibody due to immunologic memory.) The three dose groups were: 50 Microgram SparVax on Days 0, 28 and 56 (n = 91); 100 Microgram SparVax on Days 0, 28 and 56 (n = 92), and; 0.5 mL BioThrax(R) on Days 0, 14, and 28 (n = 43). At day 182, subjects receiving SparVax(TM) were re-randomized to a challenge at the original dose, on either day 182 or 364. The antigenic challenge dose (50 or 100 Microgram) each subject received was the same as the dose assigned to that subject during the initial vaccination schedule. Safety and immunogenicity were assessed throughout the study.
BioThrax(R) subjects were allowed to complete the full course of treatment, but data were not collected from these subjects after Day 70. Subjects who continued in the study were followed up for 18 months (Day 546) from the original vaccine dose.
Study results showed that there were an increased proportion of individuals experiencing injection site pain in the BioThrax(R) group as compared to the SparVax(TM) groups at both dose levels. There were no notable differences between the SparVax(TM) groups and the BioThrax(R) group regarding safety laboratory values, vital signs and ECG results. Additionally, in the antigenic challenge phase, no differences in the AE profile between the SparVax(TM) dose groups were noted.
Both vaccines were immunogenic following the 3-dose series with response rates of approximately 90%. There were no significant differences in either TNA or ELISA geometric mean titers (GMT) between the vaccine groups 14 days after the third vaccination. A strong immunologic memory response was observed at both 6 months and 12 months and no differences were seen between SparVax(TM) groups in terms of response rate or GMT measured by TNA.
The study concluded that SparVax(TM) was safe, well-tolerated and produced antibody responses comparable to the currently licensed product. The lower incidence of injection site reactions observed with SparVax(TM) may indicate that it is better tolerated than BioThrax(R), with good immunologic memory demonstrated after antigen exposure at 6 or 12 months.
“This is an important finding and supports the rationale for stockpiling a highly purified second generation anthrax vaccine utilizing modern vaccine technology as described in the March 2002 Institute of Medicine report, The Anthrax Vaccine: Is It Safe; Does it Work?,” said Mr. Wright.
The SparVax(TM) Phase II clinical trial has been funded in whole or in part with Federal funds from the National Institute of Allergy and Infectious Disease, National Institutes of Health.
Conference Call and Webcast Information
PharmAthene management will host a conference call to provide an update on the SparVax(TM) program on Wednesday, April 29, 2009, at 4:30 p.m., E.T. The dial-in number for U.S. callers is 1-866-788-0540 and for international callers is 857-350-1678. The participant passcode is 82129094.
A replay of the conference call will be available for 30 days, beginning at approximately 7:30 p.m. E.T. on April 29, 2009 until approximately 11:59 p.m. E.T. May 29, 2009. The dial-in number for U.S. callers is 1-888-286-8010, and for international callers is 617-801-6888. The participant passcode is 53903666.
The webcast of the conference call can be accessed from the company’s website at http://www.pharmathene.com. A link to the webcast may be found on the Investor Relations section of the website.
About SparVax(TM)
SparVax(TM) is a novel second generation recombinant protective (rPA) anthrax vaccine being developed for pre and post exposure protection against anthrax infection. SparVax(TM) is a highly purified, well characterized, sub unit vaccine comprised of a single protein (recombinant PA) manufactured in E.coli. Phase I and Phase II clinical trials involving 770 healthy human subjects have been completed and showed that SparVax(TM) appears to be well tolerated and immunogenic in humans. These studies suggest that three doses of SparVax(TM), administered several weeks apart, should be sufficient to induce protective immunity. In preclinical studies SparVax(TM) has also demonstrated the capability to protect rabbits and non-human primates against a lethal aerosol spore challenge of the anthrax Ames strain.
About Anthrax
According to the Centers for Disease Control and Prevention, anthrax is an acute infectious disease caused by the spore-forming bacterium Bacillus anthracis. Anthrax most commonly occurs in hoofed mammals and can also infect humans. Symptoms of disease vary depending on how the disease is contracted, but usually occur within seven days after exposure. The serious forms of human anthrax are inhalation anthrax, cutaneous anthrax, and intestinal anthrax. Initial symptoms of inhalation anthrax infection may resemble a common cold. After several days, the symptoms may progress to severe breathing problems and shock. Inhalation anthrax is often fatal, even if treated by antibiotics. Currently, antibiotics are the only drugs available for therapeutic or prophylactic use for inhalation anthrax, and post-exposure prophylaxis is the only FDA-approved indication for such products. However, antibiotic therapy, while useful, is believed to be associated with a number of limitations, including: (1) lack of activity against the toxins produced by the B. anthracis bacteria, (2) need for long-term dosing to achieve full protection, complicated by side effects and non-compliance (3) lack of efficacy when administered late in the anthrax disease cycle, and (4) lack of effectiveness against multi-drug resistant or genetically engineered strains of anthrax.
About the 12th Annual Conference on Vaccine Research
The 12th Annual Conference on Vaccine Research is sponsored by The National Foundation for Infectious Diseases (NFID), a non-profit, tax-exempt (501c3) organization founded in 1973 and dedicated to educating the public and healthcare professionals about the causes, treatment and prevention of infectious diseases. The Annual Conference has become the largest scientific meeting devoted exclusively to research on vaccines and associated technologies for disease prevention and treatment through immunization. The Conference provides high-quality, current reports of scientific progress featured in both invited presentations and submitted abstracts. The disparate fields covered in both human and veterinary vaccinology encourage valuable cross-fertilization of ideas and approaches among researchers otherwise focused on specific ideas or methods.
About PharmAthene, Inc.
PharmAthene was formed to meet the critical needs of the United States and its allies by developing and commercializing medical countermeasures against biological and chemical weapons. PharmAthene’s lead product development programs include:
For more information about PharmAthene, please visit www.PharmAthene.com.
Statement on Cautionary Factors
Except for the historical information presented herein, matters discussed may constitute forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 that are subject to certain risks and uncertainties that could cause actual results to differ materially from any future results, performance or achievements expressed or implied by such statements. Statements that are not historical facts, including statements preceded by, followed by, or that include the words “potential"; “believe"; “anticipate"; “intend"; “plan"; “expect"; “estimate"; “could"; “may"; “should"; or similar statements are forward-looking statements. PharmAthene disclaims, however, any intent or obligation to update these forward-looking statements. Risks and uncertainties include risk associated with the reliability of the results of the studies relating to human safety and possible adverse effects resulting from the administration of the Company’s product candidates, unexpected funding delays and/or reductions or elimination of U.S. government funding for one or more of the Company’s development programs, including without limitation our bid related to SparVax(TM) under the DHHS Request for Proposals for an Anthrax Recombinant Protective Antigen (rPA) Vaccine for the Strategic National Stockpile, the award of government contracts to our competitors, unforeseen safety issues, challenges related to the development, scale-up, and/or process validation of manufacturing processes for our product candidates, unexpected determinations that these product candidates prove not to be effective and/or capable of being marketed as products, as well as risks detailed from time to time in PharmAthene’s Forms 10-K and 10-Q under the caption “Risk Factors” and in its other reports filed with the U.S. Securities and Exchange Commission (the “SEC”). In particular, significant additional non-clinical animal studies, human clinical trials, and manufacturing development work remain to be completed for SparVax(TM). At this point there can be no assurance that SparVax(TM) will be shown to be safe and effective and approved by regulatory authorities for use in humans.
Copies of PharmAthene’s public disclosure filings are available from its investor relations department and our website under the investor relations tab at www.PharmAthene.com.
CONTACT: Stacey Jurchison of PharmAthene, Inc., +1-410-269-2610,
Stacey.Jurchison@PharmAthene.com
Web site: http://www.pharmathene.com/
