Genocea Biosciences, Inc. , a biopharmaceutical company developing T cell-directed vaccines and immunotherapies, yesterday presented data from a Phase 1 study of GEN-004, an investigational vaccine designed to prevent disease caused by all serotypes of pneumococcus (Streptococcus pneumoniae) The poster (G-291), titled “Safety and Immunogenicity of a Novel Lipidated Protein Subunit Streptococcus Pneumoniae vaccine,” was presented at the 54th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) in Washington, DC.


Data presented at ICAAC showed the GEN-004 study met safety, tolerability and immunogenicity goals, including increases in the blood of T helper 17 (TH17) cells, a rare cell type that provides immunity at epithelial and mucosal surfaces. By generating a TH17 T cell-mediated immune response, immunization with GEN-004 may prevent or reduce pneumococcus colonization in the nasopharynx, a precursor to infection caused by all serotypes of pneumoccocus.

The Phase 1 study was a randomized, double-blind, dose-escalation, placebo-controlled clinical trial that enrolled 90 healthy adult volunteers. The primary objective was to evaluate safety and tolerability of GEN-004, which is comprised of three protein antigens, SP0148, SP2108 and SP1912, when administered with and without aluminum hydroxide as an adjuvant. Subjects were randomized to receive 10, 30 or 100µg of each protein/dose with or without 350µg aluminum hydroxide, or placebo, and received three doses, each four weeks apart. GEN-004 was administered by an intramuscular injection.

The study showed that at 85 days after administration, GEN-004 was safe and well tolerated at all doses. The most common side effects were pain, tenderness, muscle aches and fatigue. Most were mild or moderate in intensity. There were no serious adverse events related to the vaccine.

As a secondary objective, the study measured peripheral TH17 levels, by means of IL-17 responses, and IgG (serum antibody) immune responses. IgG responses were observed at all doses tested, both in the presence and absence of the adjuvant. IL-17 responses were observed in the 100 µg dose group and were dependent on the presence of aluminum hydroxide.

The highest dose from this trial of 100µg will be further evaluated in an upcoming Phase 2a study.