IMV’s lead infectious disease candidate, DPX-RSV is a small B cell epitope peptide vaccine designed specifically to address the unmet medical needs in respiratory syncytial virus (RSV). There is currently no vaccine for RSV, which causes severe respiratory illness in the elderly and young children.The World Health Organization (WHO) estimates that RSV causes 64 million infections and 160,000 deaths each year. WHO has designated RSV a high priority vaccine target.
DPX-RSV targets the SH antigen of RSV, which may provide additional immunogenic benefit over traditional approaches for high-risk populations, especially the elderly.1 In addition, the concentrated dosage enabled by the delivery system may help mitigate injection site point-of-pain, which has been a limitation for other potential oil-based injections. Our Company holds exclusive worldwide license on applications that target the SH ectodomain antigen in RSV from VIB and Ghent University.
In April 2017, we released positive topline results from a Phase 1 clinical study evaluating the safety and immunogenicity of DPX-RSV. These results showed that 100 percent of the participants in the higher dosing cohort demonstrated sustained antigen-specific immune responses at the one-year mark following the last vaccination doses. These responses to the antigen were as high at one year as they were at six months.
We believe that these data are groundbreaking, both for us and for our industry, for several key reasons. We have long since maintained that our therapies, such as DPX-RSV, are able to engender a robust, specific and persistent response across a range of serious diseases. These data mark the first validation of the clinical utility of our platform for the prevention of infectious diseases.
Furthermore, the strength and persistence of our data is typically the type of immune response exhibited in the presence of actual infections or live attenuated vaccines, and we have achieved these results-to-date with a synthetic peptide-based formulation. Taken together, the novel target of DPX-RSV, as well as the delivery formulation, may provide an option for RSV that offers benefits over other candidates currently in development: the safety, efficiency and feasibility of a synthetic peptide formulation, as well as the intensity and persistence typically seen in a live vaccine.
RSV has been a notoriously tricky disease for the vaccine industry, and hurrying into pivotal trials has proved costly for several late-stage programs. To avoid these pitfalls and further establish confidence and momentum on our program, we are in the process of thoroughly analyzing all available data from this trial to verify our strategic options, and plan for the next stage of clinical testing.
1. Schepens, Bert, Michael Schotsaert, and Xavier Saelens. “Small Hydrophobic Protein of Respiratory Syncytial Virus as a Novel Vaccine Antigen.” Immunotherapy 7.3 (2015): 203-06. DOI: 10.2217/IMT.15.11