Researchers in the U.S. and Germany have developed a drug that may prevent vulnerable people exposed to measles from getting the disease.
They have successfully tested the drug against a virus similar to measles (canine distemper virus, or CDV) in ferrets, in which it is invariably fatal. Ferrets given the drug prophylactically and then infected intranasally with a lethal CDV dose had lower viremia and prolonged survival, they reported today in Science Translational Medicine (16 April).
Ferrets infected with the same dose of virus and treated at the onset of viremia showed low-grade viral loads, remained asymptomatic, and recovered from infection, whereas control animals succumbed to the disease.
Animals that recovered also mounted a robust immune response and were protected against rechallenge with a lethal CDV dose, they added.
The findings suggest the drug can not only treat measles in the early stages, but prevent disease in the social and household contacts of those with measles.
The researchers also generated strains of CDV resistant to the drug, and showed that the resistant viruses caused milder disease and were transmitted less efficiently.
The drug, currently known as ERDRP-0519, is an orally available, shelf-stable pan-morbillivirus inhibitor that targets the viral RNA polymerase. It was developed by Dr. Richard Plemper (PhD) of the newly founded Institute for Biomedical Sciences at Georgia State University in Atlanta and Dr. Michael Natchus (PhD), principal scientist and director of operations at the Emory Institute for Drug Discovery, in collaboration with Dr. Veronika von Messling (DVM) from the Paul-Ehrlich-Institut in Langen, Germany.
Following the successful proof of concept, the researchers are planning to conduct safety and toxicity trials in squirrel monkeys, and will have to study other animal models before moving to clinical trials.
“We’re going to need a very clean toxicology profile.” -Dr. Michael Natchus (PhD)
Monkeys are not a natural reservoir of measles, but they can be infected in the laboratory and develop human measles-like symptoms, Dr. Plemper said in an online video news conference.
“If this compound is going to be dosed prophylactically, then you’re dosing folks who are not presenting at the time with symptoms, so side effects can’t be tolerated,” Dr. Natchus added. “So we’re going to need a very clean toxicology profile.”
“This is not … an alternative to vaccination…. This is an additional option.” -Dr. Richard Plemper (PhD)
The drug, if and when it is used in humans, is not intended to replace measles immunization, Dr. Plemper emphasized.
“This is not at all developed or even conceptualized as an alternative to vaccination. In a population with overall good vaccination coverage, such a drug can induce synergistic effects, so we can hopefully rapidly silence emerging measles outbreaks.
“This message must be communicated very, very clearly,” Dr. Plemper added, saying that immunization is still the foundation for measles eradication.
“This is an additional option and hopefully combined [with immunization], we may one day succeed and eradicate measles.”~TM