Intercell’s new pneumococcus vaccine will compete with Wyeth’s Prevnar and Merck’s Pneumovax; phase 1 clinical trial begins

Intercell has begun first-in-man studies on its new vaccine candidate against pneumococcus bacteriae.

The Austrian drug maker would study safety and immunogenicity data for Intercell’s IC47 candidate in a population of 32 healthy adults.

Also called phase 1 and phase 2 clinical trials, these studies are conducted in healthy people before the drug or vaccine is tried in real-time diseases patients in the late stage phase 3 trials.

Intercell can take up the candidate for the phase 3 programme only if the results from phase 1&2 studies prove the drug safe.

Intercell said in a statement that it is starting to test on humans a vaccine candidate to prevent diseases caused by pneumococcus bacteriae in a phase I clinical trial.

The vaccine candidate is a protein-based vaccine derived from its proprietary Antigen Identification Program (AIP).

Intercell started a  phase I clinical trial in April 2009. This phase I trial is a first-in-man study with a focus to obtain safety and immunogenicity data in a small population of healthy individuals.

Intercell  isolated two lead candidates which it found to be exceptionally conserved among clinical isolates (>99.5 percent identity), cross-protective against different serotypes in lethal sepsis and pneumonia models, immunogenic in both elderly and young children and play important, non-redundant roles in bacterial multiplication, according to the the selection process of antigens described and published in the Journal of Experimental Medicine in January 2008.

In addition, the authors report for the first time opsonophagocytic killing activity for antibodies induced by proteinaceous pneumococcal antigens that is a promising in-vitro assay for potential surrogate markers.

Primarily target groups for the novel vaccine are children in the developing world, where development is being funded by the U.S.-based non-profit organization PATH, and elderly people in the developed world.

What’s the streptococcal disease?

Pneumococcus — or Streptococcus pneumoniae — bacteriae cause infections including meningitis and pneumonia, especially in small children and the elderly, and according to the WHO kill 1 million children under the age of 5 per year, Intercell said.

Streptococcus pneumoniae, or pneumococcus, is a gram-positive, encapsulated bacterium and the most common bacterial infection in both industrialized and developing countries. It is the most frequent cause of pneumonia worldwide. It accounts for most cases of bacterial meningitis in adults and it is the most common cause of bacteraemia, pneumonia, meningitis and otitis media in young children. In addition, it causes illness and death among the elderly and immunosuppressed individuals. For children younger than 5 years, it is the most common vaccine-preventable cause of death.

The bacterium is surrounded by a polysaccharide capsule and based on the differences in the composition of the capsular polysaccharides, more than 90 different serotypes have been described. Current data on pneumococcal disease in infants suggest that the 11 most common serotypes are responsible for at least 75 percent of invasive diseases. However, serotype distribution varies with age, disease and geographical region, which complicates the vaccine development.

What are the current treatments pneumococcal disease?

Invasive pneumococcal disease is traditionally treated with antibiotics. However, the emergence of multi-resistant pneumococcal strains in recent years has complicated disease management. Also, even with the use of effective antibiotic therapies, mortality rates are as high as 80 percent for patients in high risk groups.

Currently, there are two vaccines on the market recommended for different ages. A heptavalent conjugate vaccine (Prevnar / Wyeth) for children younger than 2 years targets seven serotypes of pneumococcus which account for 80 percent of all pneumococcal invasive disease in this patient group in the United States. There is also a 23-valent polysaccharide vaccine (Pneumovax / Merck) approved for use in adults (recommended age 65 years and older) which contains capsular antigens from 23 of the most common strains. Still, the vaccines are expensive and target only a limited number of the more than 90 different serotypes of the bacterium.