ID Biomedical Reports Positive Data From Clinical Testing of PGCvax

ID Biomedical has completed analysis of data obtained from several Phase I clinical studies of its Pneumococcal Group-Common Vaccine, PGCvax, in adults, elderly and toddlers.

PGCvax is being developed to prevent invasive diseases, including meningitis, caused by the bacteria Streptococcus pneumoniae (also known as the pneumococcus). These studies enrolled more than 300 subjects, who received the vaccine in a series of four different clinical trials conducted in young adults, the elderly and toddlers in 2003 and 2004.

The results demonstrated that PGCvax was well-tolerated and immunogenic in different age groups. The one-dose study in toddlers primarily addressed safety, but the trials in adults included a two-dose regimen and yielded detailed immunogenicity data. Significant (greater than four-fold) antibody responses to the protein antigen in the vaccine were demonstrated in 92 percent of young adults and 85 percent of elderly (65 years and over) subjects receiving optimal doses of the vaccine, whereas no recipients of control products had such responses. Young adults and elderly persons had nearly identical nine-fold increases in their geometric mean antibody levels.

Importantly, human antibodies induced in the clinical studies were able to protect against lethal disease caused by pneumococci when transferred to animals, and also could be shown to bind to the surface of pneumococci. The induction of cell-surface-binding antibodies is a key finding, since such antibodies can attach to the outer surface of pneumococci, where they could interact with other components of the immune system to destroy the bacteria before they induce disease. Based on these promising results, ID Biomedical has now received clearance from the Canadian regulatory authorities to initiate a Phase I study in infants, the major target population for this vaccine.