Dr John Beadle, PowderMed Chief Medical Officer, who presented the data at ICAAC, said:“Circulated influenza cannot be precisely predicted, the strains change every season. These results suggest that our vaccine could play a key role in future defence strategies against both annual flu and the pandemic threat. For bird flu it is particularly important that vaccines are able to cover a range of drift variants since the virus is likely to change very rapidly early in the pandemic.”

The current results suggest that the PMED DNA method will provide useful prophylactic vaccine defence against influenza and PowderMed will initiate phase II studies using both bird flu strains and annual flu strains in 2006. The Company is currently expanding its manufacturing capabilities in Europe in line with capacity requirements for production of its vaccines.

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PowderMed is a private immunotherapeutic company based in Oxford, UK.  The Company is focused on the clinical development and manufacture of therapeutic and prophylactic DNA-based vaccines for viral diseases and cancer. The company has 4 clinical and 3 pre-clinical stage projects.  The lead clinical programme has shown positive Phase I results in the treatment and prevention of human influenza. This technology is uniquely and easily adaptable to treat avian flu and to address the pandemic threat. PowderMed also has a product for the treatment of genital herpes in Phase I trials, and two partnered Phase I programmes in Cancer (Ludwig Institute) and HIV/AIDS (Glaxo SmithKline). PowderMed vaccines are delivered using PMED^TM (Particle mediated epidermal delivery), a needle-free, virtually painless delivery system that requires minimal medical training, allows self-administration and requires no refrigeration for stockpiling. Specifically, PowderMed’s technology delivers DNA to the epidermal layer of the skin where it is presented to the cells of the immune network, thereby creating immunity and thus facilitating both treatment and prevention of disease.

PowderMed has adopted a flexible and cost effective business strategy: company resources are used for discovery research and drug design with outsourced partners being used for its drug development and manufacturing requirements. The Company has a highly experienced management team that has a combined 160 years of experience, with Rolf Stahel as the chair of the board. The Company has sufficient funds through to the end of 2006 having raised £20 million in venture financing to date, with an additional £5 million available from its existing investor syndicate that comprises Abingworth Management, Advent Venture Partners, Isis College Fund, Oxford Bioscience Partners and SV Life Sciences.

PowderMed’s Influenza Vaccines

PowderMed DNA vaccines are made up of two components – the vaccine-specific DNA and the delivery device. The DNA vaccine consists of the standard DNA backbone with an immunologically active gene specific to each viral strain – the gene cassette. The delivery device is a fully developed and patented system, called Particle Mediated Epidermal Delivery (PMED™), whereby gold particles coated in the vaccine DNA are propelled into the skin using high-pressure helium. In this way, vaccine DNA is delivered directly to cells of the immune network in the skin, thereby stimulating immunity. This approach provides a rapid route to vaccine development that can be applied to existing and emerging flu strains including, for example, the threat of the emergence of a pandemic flu strain.

Results of previous preclinical and clinical testing of PowderMed’s DNA-based influenza vaccines, including H3 and Avian H5 strains utilising PMED, show consistent and robust immune responses in animals and humans at microgram doses.

Using PowderMed’s technology, vaccination is needle-free, virtually painless, can be easily administered without the need for trained medical personnel and it can be stored at room temperature making it ideal for large volume stockpiling and distribution.

The Company has developed a full clinical trial and manufacturing strategy that anticipates the demands that Governments may have for both annual influenza vaccine and a pandemic flu vaccine.

Background to Influenza

Flu is an acute viral infection of the respiratory tract caused by the Influenza virus. There are many different subtypes or strains of Influenza viruses, differentiated by proteins on the surface of the virus: the hemagglutinin or “HA” protein and the neuraminidase or “NA” protein. So far, 15 H and 9 N subtypes have been identified.

These viruses continually change over time and every year small modifications (“antigenic drifts”) are responsible for seasonal outbreaks or “epidemics” of Influenza. Worldwide, an estimated 100,000 hospitalisations and about 20,000 deaths occur each year from the flu or its complications (source: The National Institute of Allergy and Infectious Diseases).

Abrupt genetic recombinations of HA and/or NA proteins on the surface of the virus (“antigenic shifts”) result in the emergence of a new virus, which is a key step towards a pandemic strain. To date, there is little evidence that the H5N1 virus (associated with Avian flu) is capable of spreading from human to human, a pre-requisite for a pandemic strain, but should recombination (antigenic shift) of H5N1 occur, this strain could become responsible for a global outbreak of the disease or pandemic, with high levels of illness and death. The WHO (World Health Organization) has reported 97 human cases of avian flu since 26 December 2003. Since that date 53 deaths have been reported.

Previous Influenza pandemics:

–1918-1919 “Spanish flu” (H1N1) with up to 50 millions deaths worldwide.

–1957-1958 “Asian flu” (H2N2) caused about 70,000 deaths in the US

–1968-1969 “Hong Kong flu” (H3N2) caused about 34,000 deaths in the US

Both the 1957-1958 and the 1968-1969 pandemics were caused by viruses containing combinations of human and avian Influenza viruses.

PowderJect^® Particle Mediated Epidermal Delivery (PMED™) technology

Using the PowderJect device, DNA precipitated onto microscopic gold particles is propelled by pressurised helium gas at near supersonic speeds into the epidermis.  The microscopic gold particles (mean particle diameter 1 - 3 microns) are used as the carrier because they have the appropriate size and density needed to deliver the DNA directly into the immunologically active antigen presenting cells (APCs) of the epidermis. These cells have a mean diameter of 20 microns and thus the microscopic gold can easily enter the cell. Studies have shown that once inside the nuclei of APCs, the DNA elutes off the gold and becomes transcriptionally active, producing the encoded protein that, when presented by the APCs to lymphocytes, triggers strong T-cell mediated immune responses. It is this ability of PMED to produce a robust and reproducible T-cell mediated immune response to a broad range of viral and cancer antigens, that provides PowderMed with its unique competitive advantage in the field of DNA-based vaccines.