Phase III data presented for the first time at the 6th International Symposium on Pneumococci and Pneumococcal Diseases (ISPPD, Reykjavik, Iceland) indicate that GlaxoSmithKline's paediatric candidate vaccine Synflorix should offer protection to children against most major strains of Streptococcus pneumoniae - bacteria responsible for life-threatening invasive diseases such as meningitis and sepsis.
The candidate vaccine provides broader coverage against invasive disease, compared to the currently available paediatric vaccination as it includes three additional pneumococcal strains - 1, 5 and 7F - that are not currently vaccine preventable. These strains cause a significant number of severe childhood invasive diseases, accounting for 5-25 per cent of all cases in different regions of the world and are an increasingly prominent cause of serious disease in Europe. Moreover, the candidate vaccine has been designed with an active carrier protein to induce protection against non-typeable Haemophilus influenzae (NTHi) in addition to S. pneumoniae. The bacteria S. pneumoniae and NTHi are the two leading causes of bacterial middle ear infections (otitis media), each accounting for up to 40 per cent of cases.
The immunogenicity data presented show that the candidate vaccine elicited comparable biologically active antibody responses for each of the 7 S. pneumoniae serotypes common between the GSK candidate vaccine and the currently available 7-valent paediatric pneumococcal conjugate vaccine. Depending on serotype, at least 87.3 and up to 100 per cent of subjects studied reached the antibody response threshold in the candidate vaccine group. For the 3 additional serotypes contained only in the candidate vaccine, at least 93.1 per cent of subjects studied reached the antibody response threshold. Depending on the relative importance of serotypes 1, 5 and 7F in a respective region or country of the world, GSK's candidate vaccine has the potential to prevent more invasive pneumococcal disease than the 7-valent vaccine.
Jean Stéphenne, president of GlaxoSmithKline Biologicals, said, "The data presented today are extremely encouraging and represent a major step forward to a pneumococcal conjugate vaccine formulation, specifically designed to address the global epidemiology of pneumococcal disease in both developed and developing countries".
The candidate vaccine was filed for regulatory review with the EMEA in Europe in January 2008 with regulatory filings in the International Region in parallel. Additional regulatory submissions are ongoing.
Given the high unmet medical need in many parts of the world due to S. pneumoniae serotypes including 1, 5 and 7F, GSK has submitted a file for this potentially life-saving vaccine to the World Health Organization (WHO) for prequalification (PQ). Prequalification is a service provided by the WHO to facilitate access to medicines in less-affluent countries. A WHO prequalification would facilitate rapid access by developing world countries once the candidate vaccine is approved in Europe.
Dr. Orin Levine, Executive Director, GAVI's pneumoADIP, commented, "The fact that GSK has filed their candidate vaccine for WHO prequalification is evidence of their commitment to global access. Pneumococcal vaccines are crucial for global health, since pneumococcal disease is estimated to be the number one cause of vaccine preventable deaths in children under five years of age".