PharmAthene Presents rPA Anthrax Vaccine Data at the 2009 HHS PHEMCE Stakeholders Workshop
David P. Wright, President and Chief Executive Officer of PharmAthene, commented, "These new data are very encouraging as they demonstrate that PharmAthene's lyophilized rPA could be used to provide a stable cold-chain-free vaccine, enabling us to develop a formulation which could be stored and distributed at room temperature, an important attribute for deployment in the civilian Strategic National Stockpile."
Next Generation Anthrax Vaccines
Various government agencies, including the Institute of Medicine, have acknowledged the urgent need to stockpile next-generation anthrax vaccines employing modern vaccine technology, which offer the potential for improved safety, convenience and more rapid immunity, ideally with a potential to provide protective immunity in sixty days compared to six months for the currently licensed anthrax vaccine.
As a result of this Federal requirement, a Request for Proposals (RFP) was issued by the Biomedical Advanced Research and Development Authority (BARDA) for the acquisition of 25 million doses of rPA anthrax vaccine for the Strategic National Stockpile. The Company's second generation rPA anthrax vaccine, SparVax(TM), is currently under consideration for a major advanced development and procurement contract through BARDA.
PharmAthene's portfolio includes second generation and third generation rPA anthrax vaccine product candidates, which incorporate significant product development and technological advancements and are designed to meet these requirements.
The goal of PharmAthene's third generation rPA vaccine program is to develop a vaccine formulation which can induce a more rapid onset of protective immunity in fewer doses, and can be stored, transported and used without the need for a conventional cold chain -- an important advantage for civilian biodefense deployment within the Strategic National Stockpile.
Summary of the Data Presented
In an oral presentation entitled, "Development of a Highly Stable Lyophilized rPA-Based Anthrax Vaccine," Dr. Duchars presented results from a series of studies evaluating different approaches to increase the stability of an rPA anthrax vaccine product candidate. Of the techniques evaluated, lyophilization showed exceptional stability. An optimized lyophilized formulation of rPA was subsequently tested in an accelerated stability study at 5 degrees C; 25 degrees C; 40 degrees C; and 55 degrees C.
At 3 months, little evidence of rPA degradation was detected in the samples at all temperatures up to and including 55 degrees C. Using the mouse challenge assay, the lyophilized rPA vaccine was shown to have retained potency. Subsequent analysis at 16 months demonstrated that the rPA had retained both structural integrity and vaccine potency.
These preliminary data suggest that an optimized rPA formulation could be used to provide a stable cold-chain-free vaccine. Scale-up of the lyophilization process is currently underway.
Funding for these studies was provided under a Challenge grant (UC1 AI067223-01) from the National Institutes of Health.
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 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 HHS 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, unexpected financial obligations that could increase the rate of our cash consumption, 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 research work, non-clinical animal studies, human clinical trials, and manufacturing development work remain to be completed for the Company's lyophilized 3G rPA anthrax vaccine candidate. At this point there can be no assurance that this product candidate 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.
-- SparVax(TM) -- a second generation recombinant protective antigen (rPA) anthrax vaccine -- Third generation rPA anthrax vaccine -- Valortim® -- a fully human monoclonal antibody for the prevention and treatment of anthrax infection -- Protexia® -- a novel bioscavenger for the prevention and treatment of morbidity and mortality associated with exposure to chemical nerve agents -- RypVax(TM) -- a recombinant dual antigen vaccine for plague
SOURCE PharmAthene, Inc.
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