A novel oral antiviral agent is showing early promise as a nonvaccine treatment for measles.
Measles outbreaks have been occurring more commonly as vaccine compliance declines in some countries. This investigational drug could prove useful as a preemptive treatment in nonvaccinated individuals who are exposed to the disease.
Dr. Richard Plemper
With administration during the approximately 2-week window between infection and symptom development, the small-molecule inhibitor – which targets the viral RNA polymerase – reduced viremia by 99% in three ferrets that were infected intranasally with a lethal dose of the measles-like zoonotic canine distemper virus. All three survived, but nine control animals that received only the vehicle all died as a result of the infection, Stefanie A. Krumm of Georgia State University, Atlanta, and her colleagues reported.
Furthermore, all of the treated animals had a robust immune response and were protected against rechallenge with a lethal dose of the virus 35 days after the initial dose. In fact, none of the rechallenged animals developed signs of disease, and no virus could be isolated from peripheral blood mononuclear cells of these animals, the investigators said (Sci. Transl. Med. 2014 April 16;6:232ra52).
The drug is in the early stages of development, but if it proves safe and effective in humans, it would not be considered an alternative to vaccination, lead author Richard K. Plemper, Ph.D., said during a news conference on the findings.
"In a population with good [vaccine] coverage, such a drug could induce synergistic effects, so we could ... rapidly silence emerging measles outbreaks," noted Dr. Plemper, professor in the center for inflammation, immunity & infection at Georgia State University and in the departments of infectious diseases and pediatrics at Emory University, Atlanta, adding that the ultimate goal is global measles eradication.
The investigators plan next to test the drug in a monkey model to carefully assess for potential toxicity before moving on to human testing.
This study was funded by grants from the Agency for Science, Technology and Research, Ministry of Health, Singapore, and from the National Institutes of Health/National Institute of Allergy and Infectious Diseases. It was also supported by the German Ministry of Health and the German Centre for Infection Research. Three of the study authors, including Dr. Plemper, are inventors on a patent that includes the structure and method of use of the antiviral drug.