GlaxoSmithKline, one of the world's largest vaccine manufacturers, announced that HHS has placed another order to purchase bulk H5N1 antigen for the US national stockpile of pre-pandemic vaccines. The company also announced the start of the first North American pre-pandemic vaccine trials in the company's global pre-pandemic influenza programme.

The company has received a second task order for 22.5 million doses of 15µg H5N1 bulk vaccine antigen from the US Department of Health and Human Services (HHS) under a contract [HHS100200700027I] awarded in November 2007. This is in addition to the 5 million doses of H5N1 clade 2 bulk antigen at 15 µg HA/dose ordered in November 2006. The additional task order procures an additional 9 million doses of H5N1 clade 2 bulk vaccine produced in the 2006 manufacturing campaign and 13.5 million doses of H5N1 clade 2 bulk vaccine expected to be produced in the 2007 manufacturing campaign.

Under the terms of the contract, GSK will manufacture the bulk vaccine product at the GSK manufacturing site in Ste. Foy, Canada and store bulk H5N1 antigen at the GSK site in Marietta, PA. Terms of the contract also state that GSK may be directed by HHS to formulate this bulk antigen at some point in the future. Additionally, HHS also has the option to purchase pre-pandemic vaccines together with one of GSK's proprietary adjuvant systems, which could mean that less antigen would be needed per dose to achieve a protective immune response. Funding for this contract is provided through the Office of Biomedical Advanced Research and Development Authority (BARDA) in the Assistant Secretary for Preparedness and Response (ASPR).

David Stout, president, Pharmaceutical Operations, GlaxoSmithKline said: "We applaud the US government's proactive steps in protecting American citizens against this potential public health threat. We are committed to helping governments and public health officials around the world effectively respond to the global threat of a flu pandemic and we are pleased to be working with the US government in its preparedness efforts."

Today also marked the start of the first pre-pandemic vaccine trials involving GSK's proprietary adjuvanted H5N1 vaccine in North America. The vaccine used in these trials will be produced at the company's North American manufacturing facility in Quebec, Canada. These US studies are supported by a contract [HHS100200700029C] from BARDA/ASPR/HHS awarded in January 2007 for the advanced development of antigen-sparing pandemic influenza vaccines towards U.S.-licensure with a commitment to US production of 150 million doses of pandemic vaccine within six months of a pandemic onset.

The trials highlight the company's continuing commitment to its global pre-pandemic influenza vaccine development program. Data from earlier European studies, using a pre-pandemic vaccine produced at GSK's Dresden, Germany facility, showed that the influenza candidate vaccine may be able to induce immune responses that might protect against different strains of H5N1.

GSK's first North American pre-pandemic vaccine trial will be a phase I/II study that evaluates its H5N1 antigen alone and in combination with one of its proprietary Adjuvant Systems, in 675 subjects. This Phase I/II study is expected to lead into a larger, multi-centre, phase III trial - one of the largest in North America- which is expected to enrol approximately 4,400 subjects later in 2007.

Ripley Ballou, vice president of clinical development for flu at GlaxoSmithKline said: "The goal of our North American clinical development program is to establish GSK's second manufacturing facility as a source for H5N1 vaccine, further strengthening our efforts to support governments' pandemic preparedness strategies. The initiation of these trials underscores the importance of GSK's $2 billion investment in 2005 to create a new influenza vaccine infrastructure in North America."

This phase I/II study, which will be conducted in seven states in the United States and two provinces in Canada, is an observer-blind, randomized, active-controlled trial that will evaluate the safety and immunogenicity of two consecutive doses of H5N1 pre-pandemic vaccine. The vaccine containing H5N1 antigen alone will be evaluated against a vaccine containing H5N1 antigen in combination with the Adjuvant System, in 675 adult volunteers aged between 18 and 64 years. Results from this study will be available in early 2008.

GSK is actively pursuing research into ways to make vaccines more effective through the use of Adjuvant Systems, combinations of compounds that are designed to enhance a vaccine's ability to elicit a strong, durable and protective immune response in the human body.

GSK's candidate pre-pandemic split antigen H5N1 vaccine induced a substantial level of cross-reactive immune response against a 'drifted' strain of H5N1 virus in a clinical trial conducted in 2006. A drifted strain is one that has undergone evolution in its protective antigens relative to the vaccine; the process of 'drift' is the same phenomenon that allows new strains of seasonal flu virus to circulate and cause disease year after year. This GSK candidate vaccine was accepted for review by the Committee for Medicinal Products for Human Use (CHMP) in Europe in January 2007.

In 2005, GSK invested approximately $2 billion in expanding its vaccine manufacturing and development activities in North America, primarily through the acquisition of the Canadian company, ID Biomedical (IDB). GSK's FluLaval and Fluviral seasonal influenza vaccines for use in North America and Canada are currently produced in IDB's former facility in Quebec, Canada and Dresden, Germany respectively. Additionally, GSK is modernizing its facility in Marietta, PA, to develop and manufacture cell-culture based seasonal and pandemic influenza vaccines. These cell culture vaccine candidates are not approved in the US.