Frequently Asked Questions - Information on the Phase I/II Clinical Trial

Q1: What are the objectives of the Canadian clinical trial?

A1: The main objective of the interventional Phase I/II clinical trial is to determine whether the Chronic Cerebrospinal Venous Insufficiency (CCSVI) procedure, which entails opening blocked veins in the neck of patients, is safe and effective for patients with Multiple Sclerosis (MS).

Approximately 100 MS patients will be invited to participate in the clinical trial; At the end of this controlled double-blinded trial, all patients will have received the CCSVI procedure. All patients will be monitored over a two-year period. This will allow the research team to determine the long-term impact of the proposed procedure.

Q2: Who will be conducting the trial and how many sites are involved and where are they located?

A2: Dr. Anthony Traboulsee, Medical Director of the UBC Hospital MS Clinic, is the principal investigator of this study. Dr. Traboulsee is an internationally recognized MS expert. He is involved in the BC CCSVI Registry, an initiative launched by the Government of British Columbia last year to better understand the impact of interventional venous procedures.

The objective is to carry out the trial in four sites. Two sites, one in Vancouver and one in Montreal, have already received ethics approvals from their institutions and are ready to recruit patients. Two sites, one in Winnipeg and one in Québec City will be added pending on ethics approval.

Q3: Why will only 100 patients be recruited?

A3: Phase I/II clinical trials, which include a small group of patients, are conducted to determine the safety and efficacy of a new intervention without putting the life of patients at risk.

Complications related to the CCSVI treatments (i.e., ballooning and stents) offered abroad have been reported, and many national and international organizations advise MS patients against these treatments.

As an example, on May 10, 2012, the United States Food and Drug Administration issued an alert of the potential dangers of unproven treatment for MS and encouraged "rigourously–conducted, properly-targeted research to evaluate the relationship between CCSVI and MS".

In this context, scientific experts recommend that the safety and efficacy of the CCSVI procedure be proven before clinical trials on larger groups of patients are conducted.

Q4: When will the clinical trial start and how can MS patients participate in this trial?

A4: The clinical trial started on November 1st, 2012. Researchers involved have already met to ensure that the standardized research protocol will be uniformly used across the different sites of the study.

Dr. Traboulsee and his collaborators will coordinate the recruitment of patients for the different sites involved in the trial. The selection of potential participants who meet study criteria will be selected randomly.

Only residents of provinces where the trial will take place are eligible. Participants will have to live within a safe travel distance of a trial site, as the procedure involves surgical intervention and frequent follow up visits.

Patients who have had a CCSVI procedure will not be eligible for this trial.

Q5: When will the results of this study be available?

A5: The results of this study will be made public once the two-year clinical trial is completed.

It is important to note that the study is double-blinded. In other words, neither the subjects of the experiment nor the persons administering the experiment know the critical aspects of the experiment. This process is important as it guards against both experimenter bias and placebo effects. In this context, the researcher team will be unable to analyze and share preliminary data before the study is completed.

The selected team will monitor patients participating in the trial over a two-year period. This study will help the scientific community to determine whether the CCSVI procedure is safe and effective over the long term.

Once the study is completed, the research team will analyze the data and publish the results of their studies in scientific peer-reviewed journals.

Q6: How and which provinces and territories are involved in the trial?

A6: The multicentre trial will take place in British Columbia, Québec and, pending ethics approval, Manitoba.

Funding of the $6 million study is a collaborative effort of CIHR, the MS Society of Canada and the provinces where the trial will take place.

This federal/provincial/territorial collaboration has been recognized by key MS stakeholders including the MS Society of Canada who stated "We applaud the spirit of cooperation that the federal, provincial and territorial governments have shown in moving CCSVI to the forefront of the country's health agenda".

Q7: Will other provinces be able to join the trial at a later date?

A7: The trial involves a small number of patients; CIHR expects close collaboration amongst a limited number of different provincial sites to allow a sufficient number of patients for screening for the trial and to achieve standardization so as to minimize variability amongst diagnosis, interventions and outcome measures.

British Columbia, Québec and, pending ethics approval, Manitoba will participate in the trial. Other provinces/territories are not expected to participate in the Phase I/II clinical trial at this time.

Saskatchewan and Yukon are sending patients to a trial that just went underway in the US.

Q8: Is there other clinical trials conducted around the world to evaluate the safety and efficacy of the procedure proposed by Dr. Zamboni?

A8: According to a recent literature review1 conducted by Dr. Laupacis and his collaborators, six randomized clinical trials are currently underway around the world. Five of these trials, including the trial supported by the Government of Canada, are small-scaled trials that include from 12 to 160 patients. The trial conducted by Dr. Zamboni from Italy is the only one classified as a Phase III clinical trial and involves 679 patients.


  1. Systematic reviews of the evidence regarding chronic cerebral spinal venous insufficiency (CCSVI) and multiple sclerosis [ PDF (300 KB) - external link ]