A vaccine being developed by Emergent BioSolutions Inc. to treat the chikungunya virus showed strong results in an analysis of a Phase 2 clinical study, the company said on Tuesday.
The chikungunya virus virus-like particle (CHIKV-VLP) vaccine candidatewas well-tolerated and no significant vaccine-related safety concerns have been identified to date, according to Emergent. The interim analysis showed that with a single dose of the vaccine administered, up to 98 percent of study participants produced a neutralizing antibody response against the chikungunya virus by the seventh day. Further, the analysis revealed that the immune response was persistent through a six-month visit, including in the one-dose regimen.
The Chikungunya virus – which may cause fever, joint pain, headache, muscle pain, joint swelling, or rash – is spread to people through infected mosquitoes. Outbreaks have occurred in Africa, Asia, Europe, and the Indian and Pacific Oceans. The virus was found in the Americas for the first time in 2013 on islands in the Caribbean. There is a risk that the virus could be imported to new areas by infected travelers, according to the U.S. Centers for Disease Control and Prevention. Currently, there is no vaccine to treat chikungunya virus infection.
“Emergent is highly encouraged about our vaccine candidate as the interim data suggest that a single dose of the vaccine was able to generate a positive immune response, which persisted through the study participants’ visits at six months,” Abbey Jenkins, senior vice president and vaccines and anti-infectives business unit head, said. “Chikungunya virus infection represents a significant unmet medical need – having no vaccine or treatment available – despite its emergence as a global threat because of the highly debilitating nature of the associated disease and unprecedented magnitude of its spread.”
Virus-like particle (VLP) vaccines are multi-protein structures that mimic the organization and conformation of naturally occurring viruses, without the viral genome, that could potentially promote a stronger immune response and increased antibody production. VLP vaccines have a proven safety record, the company said, and typically the neutralizing antibodies needed to protect against chikungunya virus.
The Phase 2 study involved 415 healthy adults in three U.S. sites. Participants were given a 1- or 2-dose series with or without an adjuvant over a 4-week period.
“We look forward to completing the data set analysis and finalizing our development plan, which could allow for initiation of a pivotal trial next year,” said Jenkins of Emergent BioSolutions, a company that focuses on providing specialty products for civilian and military populations that address accidental, deliberate, and naturally occurring public health threats.
The CHIKV-VLP chikungunya virus vaccine candidate is licensed from the National Institute of Allergy and Infectious Diseases at the National Institutes of Health. It received Fast Track designation from the U.S. Food and Drug Administration in May 2018.