The steady decrease in new Ebola cases will seriously affect current and future clinical trials of investigational treatments for the disease, according to research and consulting firm GlobalData analyst Dr Daian Cheng.
Declining Ebola cases will make it difficult to recruit study participants and demonstrate efficacy for the trials.
Cheng said: "On 30 January, 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.
"The disease’s decreasing incidence meant the study was unlikely to reach a convincing conclusion regarding the drug’s efficacy."
The decreasing incidence rate will have a direct impact on patient enrollment for clinical trials of therapeutic agents, as it was proved by two trials for antiviral drugs favipiravir and brincidofovir.
In contrast, the analyst highlighted early success of anti-influenza drug, favipiravir (Avigan) in a clinical trial in Guinea, which is currently marketed in Japan by FujiFilm Holdings.
It reported positive initial results, which allowed the Guinea Government to approve its use in a limited number of Ebola treatment centres.
According to Cheng, the use of established antiviral agents will be an advantage to pharmaceutical firms, specifically if a treatment can be positioned as an option for relieving an outbreak while still being useful and profitable for other indications when the outbreak subsides.
Cheng further added: "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."
Image: Electron micrograph of an Ebola virus virion. Photo: courtesy of CDC / Cynthia Goldsmith.