Corixa Corp., a developer of immunotherapeutics, and GlaxoSmithKline Biologicals (GSK Bio) a developer of vaccines and biologicals announced that the US FDA is allowing the initiation of a Phase I clinical study to evaluate the safety and immunogenicity of a novel, proprietary prophylactic vaccine designed to induce protection against tuberculosis (TB). The trial will be conducted in the United States under the Investigational New Drug Application (IND), currently held by Corixa and will be the first study of this TB vaccine to be conducted in human volunteers.

The vaccine combines a proprietary, recombinant tuberculosis protein antigen and a GSK Bio proprietary formulation that incorporates several adjuvants including Corixa's MPL adjuvant. MPL is Corixa's flagship adjuvant, which is present in multiple GSK Bio vaccines now in late stage clinical development. The recombinant tuberculosis antigen is a fusion protein of antigenic domains taken from different Mycobacterium tuberculosis gene products that are recognized by immune system cells harvested from patients that had been infected with tuberculosis but who never showed signs of disease. The fusion protein adjuvant combination appears to have demonstrated protection against tuberculosis infection in a number of relevant animal species including mice, guinea pigs and monkeys.

The vaccine is the first recombinant tuberculosis protein vaccine ever to be tested in humans and is the result of a long-standing collaboration between GSK Bio and Corixa to develop vaccines for certain infectious diseases.

"Tuberculosis represents a significant public health problem," said Jean Stephenne, president and general manager of GSK Bio. "We believe that a recombinant tuberculosis vaccine holds great promise for protection of patients around the world against TB and we look forward to the initiation of the clinical programme for this vaccine."

"This trial initiation underscores the productivity of our development partnerships with GSK Bio," said Steven Gillis, PhD, chairman and CEO of Corixa. "Pursuing the clinical development of novel vaccines that contain both proprietary antigens and adjuvants from our discovery pipeline remains a key area of growth for Corixa. We look forward to the continued progress of the TB vaccine programme in 2004."

The trial will enroll 20 volunteers at one clinical centre in the United States. The trial will be a standard dose escalation study in which different cohorts of patients receive escalating doses of recombinant vaccine together with a constant dose of adjuvant. Patients will be evaluated for safety, and serum and immune cells will be collected post-vaccination to determine which dose of vaccine promotes the greatest anti-TB immune response.

Mycobacterium tuberculosis, or Mtb, infection causes more deaths than any other infectious disease in the world. According to the World Health Organization (WHO), each year approximately 8 million people worldwide become sick with tuberculosis and an estimated 2 million die annually from the disease. The WHO estimates that between the years 2000 and 2020 nearly 1 billion people will be newly infected with Mtb, 150 million people will get sick and 36 million will die. According to the National Institute of Allergy and Infectious Diseases, an estimated 2 billion people are infected with Mtb, including approximately 15 million people in the United States. The WHO estimates that up to 50 million persons worldwide may be infected with drug resistant strains of Mtb.