FDA, industry officials vow to minimize barriers to Ebola vaccines


US government and pharmaceutical industry officials pledged today to minimize regulatory and cost barriers to providing Ebola vaccines for West Africa, while the World Health Organization (WHO) said African regulatory officials are working on plans to speed approvals of clinical trials and licensing of Ebola drugs and vaccines.

In addition, an executive with GlaxoSmithKline (GSK), maker of one of the leading Ebola vaccine candidates, said the company aims to begin clinical efficacy trials of its vaccine in January, if not sooner, which is roughly in line with previous assessments from the WHO.

Getting quick answers

Edward Cox, MD, MPH, of the US Food and Drug Administration (FDA), said US agencies are working on clinical trial plans that should yield findings faster than is possible with conventional trials.

"We need to get to clinical trial designs that will allow us to get the right answers quickly," he said. Officials at the National Institute of Allergy and Infectious Diseases (NIAID) have "developed a process that will allow a winner to be declared early."

Cox, who is director of the Office of Antimicrobial Products in the FDA's Center for Drug Evaluation and Research, and several other experts spoke at a press briefing arranged by the American Society for Tropical Medicine and Hygiene (ASTMH), which is holding its annual meeting in New Orleans.

In response to questions, Cox elaborated, "The idea of the trial design is to look [at the data] after pairs of patients have been enrolled to see when a boundary has been crossed regarding efficacy. There'll be chances for multiple interim looks to see when boundaries have been crossed."

Another FDA official, Luciana Borio, MD, acting chief deputy scientist, explained that the planned clinical trials "are not designed to declare one winner over another. They'll include two vaccines, but they're really designed to show if any vaccine is safe and efficacious."

The two leading candidate Ebola vaccines are one developed by GSK with the US government and another developed by the Canadian government and licensed to NewLink Genetics Corp., Ames, Iowa. Several small phase 1 trials to assess safety and immunogenicity of those vaccines are now under way, with results expected in December.

A top WHO official predicted on Oct 24 that large clinical trials of the two vaccines could begin in Liberia as early as December and that hundreds of thousands of doses might be available by June 2015.

GSK: Cost won't be a barrier

At the ASTMH briefing, W. Ripley Ballou, MD, GSK's vice president of emerging diseases, said the company intends that cost will not be a barrier to providing the GSK vaccine to those who need it, if it is found effective.

He said it's impossible to predict the vaccine's cost at this point, but added, "If it's successful we know that it would be primarily for use in affected countries, and these countries can't be expected to pay for it. So we'll look for partnerships so that cost will not be a barrier in those countries."

He added that GSK will work with GAVI (the Global Alliance for Vaccines and Immunization) and other partners to find a way to make the vaccine available.

Meanwhile, regulators from 25 African countries at a meeting this week are working on a mechanism to speed the approval of clinical trials and licensing for Ebola vaccines and drugs, the WHO said in a statement. The meeting, billed as the ninth African Vaccine Regulatory Forum (AVAREF), is taking place in Pretoria, South Africa, and ends Nov 7.

To provide Ebola vaccines to vulnerable populations as soon as possible, "We need to agree on the design of clinical trials, and we need to collaborate across borders to fast-track scientific assessment, regulatory approval and roll-out," said Sarah Barber, WHO representative in South Africa, in the statement.

The WHO said the meeting has sparked broad interest among African governments because the fast-track process it aims to set up could be used as a model for other countries to speed access to potentially useful therapies in emergency situations.

Uncertainty about using serum

The WHO noted that the use of blood plasma or serum from Ebola survivors is also being considered as a treatment and that clinical trials of that approach will also need expedited review by ethics committees and regulators.

At the ASTMH briefing, the FDA's Borio said the FDA has been providing technical assistance to the WHO on plans concerning the use of convalescent serum to treat Ebola, but it's unknown whether the approach works.

"The bottom line is we don't really know whether it helps and to what degree it would help, and logistically it's difficult to implement on a large scale. Ideally we need to study it on a large scale," she said. She added that the data on the effectiveness of convalescent serum use in previous Ebola outbreaks "is just foggy."

Armand Sprecher, MD, MPH, of Doctors without Borders (MSF), the leading nongovernmental organization fighting the Ebola epidemic, commented, "We are not offering convalescent serum as a therapy now because we have no idea whether it works. We're working with the Institute of Tropical Medicine of Antwerp [Belgium] to set up a study to find that out." He said it will take time to set up the study, because convalescent serum is not an "off-the-shelf product."

Little was said at the briefing about Ebola treatments other than plasma or serum. Cox said confidentiality rules barred him from commenting on plans for trials of specific experimental drugs, though he noted that there are "plans and timelines" for such studies.

In response to questions, Sprecher said that whether the deployment of a vaccine would make a significant impact on the Ebola epidemic remains an open question. But he said a vaccine could have an immediate effect on related problems such as the lack of routine healthcare, in that it would allow healthcare workers to resume some of their usual duties unrelated to Ebola.

In other questions, Ballou was asked about the reported shortage of biosafety level 2 (BSL-2) facilities for filling vaccine vials and whether the requirement to use such facilities might be loosened.

In reply, he called the problem "a short-term issue," adding, "This is something that will be solved eventually, and it's possible that some changes in regulations might help, but I don't see this as a long-term challenge beyond 2015."

Louisiana's unwelcome mat

Alan Magill, MD, president of the ASTMH, reminded reporters that Louisiana health officials, out of fear of Ebola, told the organization that members who had worked in the Ebola-hit countries in the past 3 weeks should be advised not to come to the meeting. He said about 30 individuals canceled their plans as a result of Louisiana's action.

Magill said that in response, some members said the ASTMH should vow not to hold any future meetings in Louisiana. But he commented, "This kind of situation may have occurred in many states, not just Louisiana, so my personal response is I don't think it would be appropriate not to come back."

See also:

Nov 3 WHO statement on African regulators' meeting

Information on ASTMH briefing speakers

Related Oct 24 CIDRAP News story

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