Clinical studies challenged with decrease in Ebola cases
If current and future clinical trials cannot find enough Ebola patients for their investigational treatments, then it will be difficult to recruit study subjects to determine the safety and efficacy of the treatments.
"On January 30, Chimerix announced the decision to cease clinical investigations of its experimental Ebola drug, brincidofovir, as only a handful of participants were able to be recruited for a single-armed clinical trial in Liberia,” Daian Cheng, who works with the research and consulting firm, said, “The disease's decreasing incidence meant the study was unlikely to reach a convincing conclusion regarding the drug's efficacy."
Alternatively, favipiravir (Avigan), an anti-influenza drug, had a successful clinical trial in Guinea. The Guinea government has allowed the drug to be used in certain Ebola treatment centers as a result.
"The favipiravir trial was not hindered by low patient recruitment, possibly due to its earlier start date compared with the brincidofovir trial,” Cheng said. “The fact that Guinea's local incidence rate was higher than Liberia's might also have contributed to its outcome. The information available from favipiravir's trial indicated that the drug could lower mortality rates and accelerate recovery in patients with low or moderate levels of Ebola virus in their blood. However, in the face of diminishing cases, its future use is uncertain."
A number of clinical trials for Ebola virus vaccines were launched following the latest outbreak in West Africa, which has claimed more than 10,000 lives so far.
"Overall, Ebola's current decline means vaccine and drug manufacturers will again need to weigh the risks and benefits of developing further interventions for a disease that goes through unpredictable cycles of intense outbreaks followed by its virtual disappearance," Cheng said.