Trial of Tekmira’s Ebola drug stopped

A clinical trial of what was once thought to be one of the brightest hopes for an Ebola drug has been halted after an interim assessment concluded there was no sign the experimental product was offering overall benefit.

TORONTO — A clinical trial of what was once thought to be one of the brightest hopes for an Ebola drug has been halted after an interim assessment concluded there was no sign the experimental product was offering overall benefit.

Tekmira Pharmaceuticals announced Friday that the Phase 2 trial of its TKM-Ebola drug had been stopped in Sierra Leone. The announcement leaves the drug in limbo.

Tekmira offered no comment on whether it plans to continue to develop the Ebola drug and a sister compound designed to fight infection with Marburg fever, a disease similar to Ebola. The Burnaby, B.C.-based company did not respond to a request for an interview.

When asked by email if the drug should be shelved as an Ebola therapeutic, principal investigator Dr. Peter Horby replied: “It is too soon to say really.”

A scientist who has researched the drug in non-human primates expressed concern about the development, worrying that the decision might scupper a drug he believes shows a lot of promise.

“Knowing the mechanism of how the drug works, looking at all the non-human primate data we have, it’s hard for me to believe that the drug would not be beneficial if used under the right circumstance,” said Tom Geisbert, an Ebola virus expert at the University of Texas Medical Branch in Galveston. Geisbert does not have a financial interest in the drug.

He noted that an improved version of the drug that he and others tested in primates late last year showed greater success than the version that was being used in the trial in Sierra Leone.

And Geisbert said if TKM-Ebola is shelved, the hopes for Ebola treatment will rest almost entirely on one drug, ZMapp — the antibody cocktail created at Canada’s National Microbiology Laboratory in Winnipeg based on antibodies created in Winnipeg and at the U.S. Army Medical Research Institute of Infectious Diseases in Frederick, Md.

“I can tell you (from) all the monkey studies that we do, you’ve got ZMapp and this one. And there’s a gigantic gap between those two drugs in monkeys and everything else…. You’re dropping off a cliff to the next thing down,” Geisbert said.

When the World Health Organization convened a meeting of experts last September to look for treatment options for the then-mushrooming Ebola outbreak, TKM-Ebola was listed as one of the leading candidates among a very small group of potential drugs.

But privately, some scientists have wondered whether the drug would be well tolerated. While it’s not clear whether that became a concern during the clinical trial, the Tekmira statement quotes Horby saying “final conclusions on the efficacy and tolerability of the drug” cannot be made until the data the trial generated are fully analyzed.

A study published in April described using TKM-Ebola on two Americans who contracted Ebola in West Africa and were flown to the U.S. for care. Both survived, but the doctors said they could not determine if the drug had contributed to their recovery. Both also received blood transfusions from Ebola survivors.

Likewise, the doctors could not say if the drug contributed to the severity of symptoms recorded. In one of the patients, TKM-Ebola was discontinued after six days because his condition worsened.

“Future studies with siRNA products should direct attention to the possibility of adverse effects by the mechanism of immune activation,” the physicians wrote in the journal Clinical Infectious Diseases.

The acronym siRNA stands for small interfering RNA, which is the class of drugs to which TKM-Ebola belongs. They work by silencing targeted disease-causing genes.

Geisbert said he has never seen toxicity problems in primates treated with the drug.

Clinical trials are designed with built-in triggers which, if reached, require the research team to pause and re-evaluate. This trial reached one and the conclusion was that “continuing enrolment was not likely to demonstrate an overall therapeutic benefit,” the Tekmira press release said.

Horby, an associate professor of infectious diseases and global health at the University of Oxford, said the researchers must now study the data and interpret the results “in the context of the patient mix and other variables.” He declined to be interviewed.

It is not clear how many patients had actually been enrolled in the trial by the time it was stopped. It was originally designed to test the drug on 100 Ebola patients.

The testing design was unusual. Instead of randomly assigning people to either get the drug or get standard treatment, Ebola patients who were given the drug were compared to previous Ebola patients. The research was funded by Britain’s Wellcome Trust charity.

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

More than 120,000 Albertans have signed up to get the COVID-19 vaccine in the first two days of appointment bookings. (Photo courtesy Alberta Health Services Twitter)
Alberta Health Services apologizes after seniors struggle to book vaccine appointments

The CEO and president of Alberta Health Services is apologizing after seniors… Continue reading

Red Deer’s Kyle Moore, 26, will be a houseguest on Season 9 of Big Brother Canada. (Photo courtesy Big Brother Canada)
Red Deer man will be a houseguest on Big Brother Canada

A Red Deer man will be a houseguest on the upcoming season… Continue reading

Red Deer Public Schools says that in the absence of additional funds from the provincial government, there was no consideration of using alternate classroom sites in the district. (AP Photo/Gregory Bull)
Red Deer Public Schools launches online engagement process

Red Deer Public schools is seeking community input to help ensure a… Continue reading

Red Deer Rebels defenceman Mason Ward battles with a Medicine Hat Tigers’ forward during the WHL Central Division season opener. (Photo by Rob Wallator/ Red Deer Rebels)
Tigers come back to spoil Red Deer Rebels home opener

It’s been nearly 345 days since the Red Deer Rebels last played… Continue reading

Students walk into Hunting Hills High School, which is one of the Red Deer Public Schools with solar panels on its roof. (Photo by SEAN MCINTOSH/Advocate staff)
Red Deer high school was placed in lockdown following potential threat

Hunting Hills High School was placed in a lockdown Friday after Red… Continue reading

An arrest by Red Deer RCMP is facing online scrutiny. No charges have been laid and the incident is still under investigation. (Screenshot of YouTube video)
Red Deer RCMP investigating violent arrest caught on video

Police say officer ‘acted within the scope of his duties’

A health-care worker prepares a dose of the Pfizer-BioNTech COVID-19 vaccine at a UHN COVID-19 vaccine clinic in Toronto, Thursday, Jan. 7, 2021. A single dose of Pfizer-BioNTech's COVID-19 vaccine is barely enough to cover the average pinky nail but is made up of more than 280 components and requires at least three manufacturing plants to produce. THE CANADIAN PRESS/Nathan Denette
From science to syringe: COVID-19 vaccines are miracles of science and supply chains

OTTAWA — A single dose of Pfizer-BioNTech’s COVID-19 vaccine is barely enough… Continue reading

Crosses are displayed in memory of the elderly who died from COVID-19 at the Camilla Care Community facility during the COVID-19 pandemic in Mississauga, Ont., on November 19, 2020. The number of people who would have died from a COVID-19 infection is likely to be much higher than recorded because of death certificates don't always list the virus as the cause of a fatality, experts say. THE CANADIAN PRESS/Nathan Denette
Death certificates don’t accurately reflect the toll of the pandemic, experts say

The number of people who would have died from a COVID-19 infection… Continue reading

Wetaskiwin RCMP say a Maskwacis man died after he was struck by a vehicle. (File photo by Advocate staff)
Clare’s Law in Saskatchewan used handful of times; Mounties review their role

REGINA — A first-of-its-kind law in Canada meant to warn those at… Continue reading

The Magpie river in Quebec is shown in a handout photo. THE CANADIAN PRESS/HO-Boreal River MANDATORY CREDIT
Quebec river granted legal rights as part of global ‘personhood’ movement

MONTREAL — With its kilometres of rapids and deep blue waters winding… Continue reading

Thorough sanding of a table top is usually the first step to renewing a finish. Wax contaminants can sometimes still remain on a surface like this after sanding. Cleaning with rubbing alcohol and a rag gets rid of these contaminants without leaving a residue behind. (Photo by Steve Maxwell)
Houseworks: Fixing wood finishes

Q: How can I stop polyurethane from beading up on a mahogany… Continue reading

Need a knife? There are knives of all shapes and sizes at The Kitchen Store.
Hints from Heloise: Finding a good set of kitchen knives

Dear Readers: A good set of knives in the kitchen is a… Continue reading

Runner Melissa Bishop-Nriagu speaks to the media at the opening news conference at the Canadian Track and Field Championships Thursday, July 25, 2019 in Montreal.THE CANADIAN PRESS/Ryan Remiorz
Canadian athletes struggling to find competition as they try to qualify for Tokyo

Canadian athletes struggling to find competition as they try to qualify for Tokyo

Most Read