Saskatchewan had planned to put up $2.2 million to have 86 patients take part in the trial at a medical centre in Albany, N.Y. But the centre has told the province that it won't test the therapy that involves opening blocked neck veins.
The trial lead, Dr. Gary Siskin, said they couldn't get enough volunteers for a valid result.
"Meaning that we needed to have a certain number of patients where, at the end of the trial, we'd be able to test the data that we had in a statistically meaningful way and without the right number of patients, those results would be meaningless," Siskin said Monday.
Just under 200 people were needed.
Siskin said he believes there are two reasons for the lack of volunteers.
One is that some physicians question the therapy and didn't push patients to join the trial.
The second is that it was a double-blind trial — meaning half of those participating would have received liberation therapy and half would get a placebo procedure. The patients would not know which one they got for several years.
"It's easy to say that everyone would do it if they knew that they would all get treated," he said. "But if only half the patients were to get treated and half the patients would undergo a sham procedure, not everyone is always willing to do something like that."
Seven patients from Saskatchewan had already travelled to Albany. Six had a procedure done while one was found ineligible for the trial.
The treatment is based on a hypothesis by Italian vascular surgeon Dr. Paolo Zamboni that a condition he dubbed chronic cerebrospinal venous insufficiency, or CCSVI, may be linked to multiple sclerosis. The theory suggests that narrowed neck veins create a backup of blood that can lead to lesions in the brain and inflammation.
Liberation treatment involves opening up the veins with balloon angioplasty, the same procedure used to unblock coronary arteries.
Health Minister Dustin Duncan said news that the trial was cancelled is disappointing for some 3,500 Saskatchewan people who want to know whether the treatment can help relieve MS symptoms.
"It's a setback in terms of the research," said Duncan.
"Tomorrow we begin the search for where Saskatchewan's role is in MS research going forward."
Duncan said the province's first choice is to be involved in another double-blind study. The health minister said Saskatchewan would like to join a national trial but added that was "unlikely" to happen because the provinces have already been selected.
"We want to be involved in MS research, that may be continuing with liberation therapy, but it may be outside of that as well that we will pursue," said Duncan.
Canada has one of the highest rates of MS in the world at 240 cases per 100,000 people. In the Prairies, the rate is even higher at 340 per 100,000 people.
Liberation treatment has not been approved in Canada and people who want it pay thousands of dollars out of their own pockets to have the procedure done abroad.
New Brunswick is the only province that provides funds to help MS patients get the treatment. However, the New Brunswick Medical Society said in July that recent studies have shown liberation therapy doesn't work for the majority of patients and the money would be better spent on clinically effective treatment.
A small clinical trial out of the University of Buffalo found in March that the intervention did not improve patients' symptoms and in some cases even made their disease worse.
The study of 30 MS patients concluded that the treatment is safe, but researchers said it showed no benefit on numerous measures of symptoms, disease progression and quality of life. As well, MRI scans showed some patients had increased brain lesions, one of the hallmarks of the progressive neurological disease, after undergoing the procedure.
Siskin said the larger double-blind study is important and he hopes it can be done in the future.
"You know, maybe this was just a little bit ahead of where it needed to be, but I think that ultimately someone is going to need to do a trial that blinds people to what treatment they receive in order to really understand what type of benefit this procedure has for patients," he said.
"I believe that this trial needs to be done at some point."