A drug that takes aim at a novel target for RSV has shown promising topline results in an early clinical trial. As of March 2016, Immunovaccine was one of six companies or government agencies working on about 17 RSV vaccine candidates in various stages of clinical trials, according to a list from the World Health Organization. Marianne Stanford, PhD, vice president of research at Immunovaccine, said her company’s approach is “completely different” than other RSV vaccine candidates because its drug DPX-RSV targets the small hydrophobic protein, which is expressed at the surface of the cell.
Stanford notes that most other vaccine candidates target either the F or G proteins.
“Our primary indication is in the elderly, who have gotten RSV multiple times, so they have immune responses to F and G and they’re not protected. Our hypothesis is, let’s mount an immune response against something that they don’t typically have an immune response to, and then sort of circumvent infection that way. That makes it very different from everything else that’s out there,” explains Stanford. “What we’re trying to do is target immune response not against the virus particle, but against the infected cell.”
In positive topline results from a phase 1 trial conducted at the Canadian Center for Vaccinology, Immunovaccine said DPX-RSV showed antigen-specific immune responses at least 6 months after the last vaccination in 15 of 16 participants, including 8 of 8 participants in the low-dose and 7 of 8 in the high-dose cohorts, reports Healio. In addition, the drug was well tolerated with no serious adverse events in any study participants.
Stanford also noted the high burden of RSV in children, as well as the challenges of developing a vaccine needed so early in life, reports Healio.
“Because we’re working in the elderly, we really need something that’s going to generate a strong immune response, and that’s what our formulation does,” says Stanford. “Therefore, another approach to protect this population is to immunize mothers before or during pregnancy so that they pass along a sufficient immune response to protect young babies. As introducing a novel, adjuvanted vaccine to the very young can be a challenge, this is likely the approach that DPX-RSV could undertake to protect young children.”