Experimental stem cell therapy tested for rare lung disease

April 30, 2018

A Canadian-led research team has launched a clinical trial of an experimental stem cell therapy for pulmonary arterial hypertension. This rare and deadly disease occurs when the arteries that supply blood to the lungs become so damaged that blood can’t flow properly to take up oxygen. It can strike anyone at any age, and typically affects women often in their prime. In some cases, pulmonary hypertension is caused by a defective gene, but in most cases the cause is unknown. 

The University of Ottawa Heart Institute’s Pulmonary Hypertension Clinic is the first site for this multi-centre trial. Dr. George Chandy, a lung specialist at The Ottawa Hospital and an assistant professor at the University of Ottawa, is leading the Ottawa site of the trial. 

“Current treatments for pulmonary hypertension can relieve symptoms for a time, but most patients will experience a progression of disease requiring more advanced therapies or a lung transplant. Unfortunately, many patients die while waiting for a more definitive therapy,” said Dr. Chandy. “We hope this therapy will get at the root cause of the disease by repairing the damaged blood vessels and help patients live longer and healthier lives.” 

The experimental therapy starts with collecting a patient’s own white blood cells and sorting them into different components. One component is grown in the laboratory under special conditions to obtain cells called endothelial progenitors. These cells can promote repair and regeneration of blood vessels, acting like stem cells. The cells are then genetically engineered to produce greater amounts of nitric oxide, a natural substance that enhances their regenerative activity and enlarges blood vessels. The gene-enhanced cells are then injected directly into the same patient through a simple intravenous injection to be carried to the lung. 

This therapy has previously been tested in laboratory studies and a Phase I clinical trial to test safety in seven patients. 

The Phase II randomized, placebo-controlled, double-blind trial will use an innovative design to test whether the therapy is effective in 45 patients at up to nine centres across Canada. This design will allow all participants to receive at least one course of the cell therapy (four injections), either in the first or second six months of the trial. One arm of the trial will receive two courses of cells, for a total of eight injections. 

As this therapy is experimental, it is impossible to say if patients who receive the therapy will benefit. 

The trial is expected to also enroll patients at the University of Alberta Hospital, Vancouver General Hospital, London Health Sciences Centre, Toronto General Hospital, Jewish General Hospital and Institut universitaire de cardiologie et de pneumologie de Québec - Université Laval. Patients wishing to participate should speak with their medical specialist. Eligibility criteria and other details are available at


  • This trial was approved by Health Canada and the Ottawa Health Science Network Research Ethics Board.
  • The cells are genetically engineered and manufactured at The Ottawa Hospital’s Biotherapeutics Manufacturing Centre.
  • This experimental therapy was pioneered by Dr. Duncan Stewart while he was a cardiologist and scientist in Toronto. Dr. Stewart is now the Executive Vice-President of Research at The Ottawa Hospital and a professor at the University of Ottawa.
  • This trial is sponsored by Northern Therapeutics, a company co-founded by Dr. Stewart. As an expert in pulmonary hypertension, Dr. Stewart provides advice to Northern on the administration of the trial. Dr. Stewart does not receive a salary from Northern and has no role in enrolling patients in the trial.
  • Many organizations have supported the research that led to this trial, including The Ottawa Hospital Foundation, the Canadian Institutes of Health Research, the Ontario Ministry of Research, Innovation and Science and the Stem Cell Network.

University of Ottawa Heart Institute  he University of Ottawa Heart Institute has flourished into one of Canada’s most distinguished heart health centres for the unparalleled care it provides to its patients, a world-renowned research Institute that brings science from bench to bedside, and the country’s main influencer when it comes to preventing heart disease. Its promise remains the very pillar on which it was built: Always putting patients first.

The Ottawa Hospital: Inspired by research. Driven by compassion The Ottawa Hospital is one of Canada’s largest learning and research hospitals with over 1,100 beds, approximately 12,000 staff and an annual budget of over $1.2 billion. Our focus on research and learning helps us develop new and innovative ways to treat patients and improve care. As a multi-campus hospital, affiliated with the University of Ottawa, we deliver specialized care to the Eastern Ontario region, but our techniques and research discoveries are adopted around the world. We engage the community at all levels to support our vision for better patient care. See for more information about research at The Ottawa Hospital. 

University of Ottawa: A crossroads of cultures and ideas The University of Ottawa is home to over 50,000 students, faculty and staff, who live, work and study in both French and English. Our campus is a crossroads of cultures and ideas, where bold minds come together to inspire game-changing ideas. We are one of Canada’s top 10 research universities—our professors and researchers explore new approaches to today’s challenges. One of a handful of Canadian universities ranked among the top 200 in the world, we attract exceptional thinkers and welcome diverse perspectives from across the globe.

Media contacts 

Vincent Lamontagne Director, Corporate Communications Ottawa Heart Institute 613 761-4427 613-899-6760 (cell) 

Jennifer Ganton Director, Communications and Public Relations Ottawa Hospital Research Institute 613-798-5555 x 73325 613-614-5253 (cell)