Johnson & Johnson Pulls Plug on Dengue Drug

Johnson & Johnson is discontinuing its phase 2 field study on the efficacy of a candidate drug for dengue, according to a company press release. The study was designed to evaluate the efficacy of an investigational drug known as mosnodenvir for the prevention of dengue virus in adults aged 18-65 years. 

No safety issues were identified; the study was discontinued as part of a reprioritizing of Johnson & Johnson’s communicable diseases research and development portfolio, according to the release. Final analyses of the study data are still in progress, but all participants have completed the study protocols and will be notified of the results. 

Data from phase 1 and phase 2a clinical studies showed that mosnodenvir (formerly known JNJ-1802) was safe and well-tolerated, and phase 2a human challenge data showed antiviral activity against dengue compared with placebo, according to the company, which pledged to share any further study results with the medical community.

Alternatives in the Works

Mosnodenvir is an antiviral drug, not a vaccine, said Anna Durbin, MD, professor of international health and director of the Center for Immunization Research at Johns Hopkins Bloomberg School of Public Health, Baltimore, in an interview.

However, “the drug would work like a vaccine,” said Durbin. “The goal was to give the drug, which would then prevent dengue from replicating after infection, so that if you were exposed to dengue, you wouldn’t get sick,” she said. The drug could be given to those who couldn’t take the vaccine (which is a live vaccine), such as immunosuppressed individuals and pregnant women, she added. 

As for alternatives to mosnodenvir, “a dengue vaccine is licensed in Europe, Latin America, and Asia (QDenga) that works well against DENV1 & DENV2, and another vaccine manufactured by the Instituto Butantan in Brazil that looks very promising,” Durbin told Medscape Medical News. The Brazilian product was developed by the National Institutes of Health and licensed to the Instituto Butantan, she noted.

To succeed, a dengue vaccine must work against all four existing serotypes, Durbin emphasized. “If it doesn’t provide protection against all four viruses, it may lead to more severe dengue if infected by the viruses it doesn’t cover,” she explained. “The live vaccines need to infect and replicate to induce immunity, so all four components of the live dengue vaccine must infect and replicate. The Instituto Butantan vaccine has four components that all infect and replicate, and this will likely be a very safe and effective vaccine,” she said.

Durbin had no financial conflicts to disclose.