US-based Genocea Biosciences has reported Phase I trial data of GEN-004, an investigational vaccine, designed to prevent disease caused by all serotypes of pneumococcus (Streptococcus pneumoniae).
The company has presented the data at the 54th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) in Washington, DC.
Results showed that the GEN-004 trial 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.
The company said that by generating a TH17 T cell-mediated immune response, immunisation with GEN-004 may prevent or reduce pneumococcus colonisation in the nasopharynx.
A total of 90 healthy adult volunteers were enrolled in the randomised, double-blind, dose-escalation, placebo-controlled Phase I trial.
Primary objective of the trial was to assess the 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.
During the trial, subjects were given 10µg, 30µg or 100µg of each protein/dose with or without 350µg aluminum hydroxide, or placebo, and received three doses, each four weeks apart.
The trial showed that at 85 days after administration by an intramuscular injection, GEN-004 was safe and well tolerated at all doses.
Pain, tenderness, muscle aches and fatigue were the most common side effects, while there were no serious adverse events related to the vaccine.
The trial’s secondary objective was to measure 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, while IL-17 responses were observed in the 100µg dose group and were dependent on the presence of aluminum hydroxide.
Image: Streptococcus pneumoniae in spinal fluid. Photo: courtesy of BlueMonday.