Toronto: Drugs normally used to treat HIV may also be effective at inhibiting the deadly Ebola virus that is transmitted from human to human by infectious body fluids, a new study has claimed.
Researchers used a mini-genome system to rapidly evaluate candidate drugs that could inhibit the Ebola virus. The results provide details on the procedure for evaluating candidate anti-Ebola drugs and comparing the antiviral effectiveness of eight drugs from three different drug classes.
Interferons and anti-HIV drugs showed antiviral activity against the Ebola virus in the studies. To date, no vaccines, treatments, or post-exposure prophylaxis are available for Ebola. The screening procedure - used in US to model and study
virus replication - allows for continuing evaluation of new antivirals or anti-Ebola drugs, since there is a likelihood of future Ebola outbreaks. This is the first time this method has been used to test anti-Ebola drugs.
Research on new Ebola therapies has been limited by an inability to compare antiviral effectiveness, since cell model systems, treatment regimens and results are so varied that it is difficult to compare effectiveness amongst the compounds, and prioritise which ones are most promising to pursue.
"During this recent Ebola outbreak it became clear that many different experimental drugs were being considered, yet studies to evaluate the effectiveness of candidate drugs are hampered by the limited availability of appropriate safety level labs around the world and the difficulty of comparing
results when different model systems were being used," said Eleanor Fish from the Toronto General Research Institute (TGRI), who led the study.
The method and technology used for this study can be performed in most labs and evaluation of two and three drug combinations can also be examined using this method. "Using this technology, scientists will be able to measure the inhibitory effects of their experimental drugs on the replication of Ebola virus, allowing us to compare results with confidence.
This approach will also decrease the possibility of the emergence of drug resistance," said Fish. Hemorrhagic fevers like Ebola have a high mortality rate
and are transmitted from human to human by infectious body fluids.
Using human cells and a model infection system, the researchers compared how well eight different drugs, in different combinations, at different doses and at times post-exposure, were able to inhibit the virus.
Interferon beta, the most potent inhibitor of Ebola which the team identified as a result of the screening, is now part of a clinical trial of individuals who were infected with Ebola during the recent outbreak in Guinea.
"It was found that drugs normally used to treat HIV/AIDS were also effective at inhibiting Ebola, alone, but more so in combination with interferon beta," said Donald Branch from University of Toronto. The study was published in the journal PLOS.
