Hookipa Biotech AG, an immunotherapy company developing next-generation cancer immune therapeutics and vaccines based on the Company´s proprietary arenavirus vector platforms, announces publication in the January 2017 issue of the peer-reviewed journal Clinical and Vaccine Immunology(1), of data confirming the potential of Hookipa’s HB-101 Vaxwave® to provide an effective and novel bivalent vaccine that confers better protection against congenital (maternal transmission) cytomegalovirus infection in the gold standard animal model, the guinea pig model, in reducing pup mortality.
The Clinical and Vaccine Immunology publication is based on collaborative work between Hookipa Biotech and a leading US Institution, the Centre for Infectious Diseases and Microbiology Translational Research and Department of Pediatrics, University of Minnesota Medical School, USA. The work was headed by Dr Mark R. Schleiss, with the research being supported by grants from the US National Institutes of Health (NIH), the Austrian Research Promotion agency, and funding from Hookipa Biotech. An accompanying editorial(2) by Professor David I. Bernstein highlights the value of Arenaviruses in general in eliciting strong and long lasting humoral and cellular immune responses.
The research by Schleiss et al. shows that a non-replicating lymphocytic choriomeningitis virus (rLCMV) vectored vaccine expressing a novel bivalent combination of human cytomegalovirus glycoproteins, a cytoplasmic tail-deleted gB [gB(dCt)] (a neutralizing antibody target) and pp65 (a T cell target) is more effective in the guinea pig model of congenital cytomegalovirus infection at inducing B & T cells, and improving pup survival, than a monovalent vaccine.
“Cytomegalovirus is one of the most significant viral pathogens during pregnancy. By preventing congenital human CMV infection, a preconception vaccine could provide a highly cost-effective public health advance,” said Dr Schleiss. “Our study, in a guinea pig CMV congenital infection model, showed improved guinea pig pup survival, from a mortality of 93% in the control group, to 8% in the bivalent population. These are very encouraging data.”
To measure protection against mortality and disease following rLCMV-vectored vaccination, the researchers initially evaluated the immunogenicity of gB and pp65 in mice and rabbits. The researchers then went on to analyse 63 litters of guinea pigs, yielding over 200 pups, across five groups covering both monovalent vaccine groups, gB(dCT) and pp65, the bivalent combination, and two control groups.
“The collaborative work published in the highly regarded journal Clinical and Vaccine Immunology adds significant validation for our Vaxwave® platform, further highlighting its versatility, and supporting the development of our lead vaccine candidate, the novel bivalent HB-101, to prevent CMV infections,” stated Joern Aldag, Chief Executive Officer of Hookipa Biotech. “With strong pre-clinical safety and efficacy data obtained for an optimized Vaxwave® CMV vaccine candidate we are looking forward to the readout of preliminary HB-101 data from a Phase 1 dose escalation trial in Q1 2017. Of note, our arenavirus based expression technology does not elicit vector-neutralizing antibody responses, allowing for administration of homologous booster vaccination.”