February 3, 2015

expert reaction to clinical trial of brincidofovir, an experimental Ebola treatment, being stopped

An experimental Ebola treatment being trialled in Liberia has been halted, because the number of cases in the country has fallen so low that a clear result is unlikely.

Prof. Jonathan Ball, Professor of Molecular Virology, University of Nottingham, said:

“In an efficacy trial, you are trying to show that a drug or vaccine either helps cure or prevent Ebolavirus infection, so a decreasing caseload means that these treatment and vaccine trials become more difficult to carry out.

“The number of people that you need to enroll to show that the drug or vaccine is beneficial is predicated by the benefit that you think the intervention will provide – the more beneficial the drug or the vaccine is, the smaller the number of people that need to be recruited and, crucially, vice versa.

“This outbreak isn’t over yet, but the signs are looking good. What it has taught us is that we need to be better prepared for next time. Vaccines and drugs may have a role in the future, but there are too many ‘at-risk’ countries where healthcare infrastructures are inadequate, and this needs to be addressed.

“The falling Ebolavirus case number is testament to the increased effort that we saw towards the end of last year. Effort focused on infection prevention and control, increased numbers of healthcare workers, treatment centres, burial teams and educators.”

Prof. Andrew Easton, Professor of Virology, University of Warwick, said:

“This announcement reflects the huge reduction in patients presenting with Ebola virus disease which is excellent news, indicating that the infection is being brought under control and that we can look forward to it being eradicated from West Africa in the coming weeks and months. However, the reduction in patient numbers means that the trials of drugs to combat Ebola virus are compromised and cannot produce results that can be properly interpreted to establish whether they are having an effect. In this situation the sensible approach is to suspend the current studies rather than persevere with no likelihood of obtaining a clear conclusion. This is obviously disappointing. However it is vital that the advances that have been made in identifying potential treatments continues and that ongoing tests on vaccines to establish their safety and possible efficacy continue with the same sense of urgency that has been seen in recent months. The momentum must be maintained to ensure that when Ebola virus appears again – as it will somewhere – we are in a position to prevent a devastating outbreak such as the one we have been watching over most of the last year.”

Declared interests

None declared