Genocea Biosciences, Inc., a clinical-stage company pioneering novel T cell vaccines, announced today that it has initiated a Phase 1 study of GEN-004, an investigational vaccine candidate for pneumococcus (Streptococcus pneumoniae), a major cause of infectious disease-related death globally. GEN-004 is the first vaccine candidate designed to prevent infections caused by all strains of pneumococcus through a novel T cell-mediated mechanism of action.
According to The World Health Organization, roughly half a million children less than five years of age die of pneumococcal disease annually. Pneumococcus naturally colonizes the nasopharynx, or nose and throat. The bacterium can become dangerous, especially to the very young and the elderly, if it is not cleared from the nasopharynx and enters the lungs and bloodstream, where it can be responsible for life-threatening illnesses such as bacteremic pneumonia, meningitis and sepsis.
Several publications have indicated that TH17 responses are a natural mechanism to clear pneumococcus from the nasopharynx. GEN-004 contains three unique protein antigens, SP0148, SP1912, and SP2108, shown by Genocea's proprietary antigen discovery platform, ATLAS™, to be associated with protective TH17 T cell responses against pneumococcus in humans. In preclinical studies presented at the International Symposium on Pneumococci and Pneumococcal Diseases (ISPPD) in 2012, GEN-004 significantly reduced nasopharyngeal colonization by stimulating TH17 immune responses.
Each protein in GEN-004 is also conserved across all sequenced strains of pneumococcus, meaning that GEN-004 could represent a universal vaccine against pneumococcus working through a novel mechanism of action. There are more than 90 known strains of pneumococcus. Approved vaccines prevent disease caused by the most prevalent strains of pneumococcus, but do not prevent disease caused by strains not in the vaccines. Emerging evidence suggests that strains not in the existing vaccines play an increased role in causing pneumococcal disease.