Vaccine Against H5N1 (Avian Influenza) Manufactured For Clinical Development, PowderMed

Main Category: Bird Flu / Avian Flu
Also Included In: Flu / Cold / SARS
Article Date: 01 Aug 2005 - 17:00 PDT

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PowderMed, the immunotherapeutics company focused on the development and manufacture of DNA-based vaccines for viral diseases and cancer, has announced that it has progressed its H5N1 Avian influenza vaccine programme into the final stages of preclinical development. PowderMed has produced an H5N1 vaccine by cloning the H5 gene from the current circulating avian flu strain ("the gene cassette") into the company's proprietary DNA vaccine backbone and the vaccine is now ready for development. Manufacturing and toxicology studies are now in progress, and it is anticipated that this vaccine will enter clinical trials by the middle of 2006.

Commenting on the programme, Dr Clive Dix, CEO of PowderMed said:

"We are very excited by the potential for our flu vaccine technology to address the major healthcare challenge that influenza presents, in particular in the event of an avian flu or other pandemic outbreak. Our technology has significant advantages over current flu vaccine technology particularly in terms of the speed of response in the event of a pandemic. As soon as a new influenza strain becomes known, our "plug and play" system would enable us to rapidly insert the relevant DNA gene cassette into our standard DNA backbone. A PowderMed manufacturing facility will be capable of delivering the vaccine requirements of an entire country within 3 months. This is not possible for other technologies."

Just 1.2kg of vaccine DNA would be sufficient to vaccinate the entire population of the US twice - an initial dose and a booster dose. PowderMed has carried out a detailed feasibility study with contract manufacturing partners, which concludes that it could establish a manufacturing capability with a surge capacity of 150 million influenza vaccine doses in a three-month period. Dr Dix points out that this is critical since, "No other vaccine technology offers this speed of response. In the event of a pandemic, most deaths and illness will occur in the first six months of an outbreak. We believe that our technology offers the best potential to save lives and minimise the economic impact of a flu pandemic."

The Avian flu vaccine uses the same standard DNA vaccine backbone as PowderMed's annual flu vaccine, which has already successfully completed a Phase I clinical trial (www.powdermed.com/media.htm) and will enter Phase IIb trials in 2006.

About PowderMed Ltd
powdermed.com

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 for Cancer Research) and HIV/AIDS (Glaxo SmithKline). PowderMed vaccines are delivered using PMEDTM (Particle mediated epidermal delivery), a needle-free, 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 pandemic influenza vaccine

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.

In the case of the Avian flu vaccine, the H5 Vietnam gene cassette is used. This gene is specific to current Avian flu and encodes part of the flu virus' protein shell. When the vaccine is administered, into the surface of the skin, the H5 gene is expressed to produce the virus protein. This harnesses the individual's immune system to mount an immune response against the protein, such that, in the event of later exposure to actual Avian flu virus, the immune system will be able to destroy the flu virus and thus provide protection.

Results of previous preclinical and clinical testing of PowderMed's DNA-based influenza vaccines, including H3 and pandemic H5 strains utilising PMED, show consistent and robust immune responses in animals and humans at micro-gram 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.

Reference URL
powdermed.com/media.htm

SOURCE: alphagalileo.org

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