Viral therapy for cancer: Frequently asked questions from patients and families

April 26, 2017

What is viral therapy for cancer?

Viral therapy for cancer, also called oncolytic viral therapy or viral immunotherapy, makes use of viruses to treat cancer.

Typically we think of viruses as tiny bugs that infect our body and cause diseases like the flu, but in this case, viruses are modified to infect and kill cancer cells without harming healthy, normal cells. These viruses can also stimulate the body’s own immune system to recognize and attack cancer cells, which makes them a kind of immunotherapy.

Researchers are studying many different kinds of viral therapies for cancer.

How well do viral therapies work?

Viral therapies have shown promise in laboratory studies of cancer. Some viral therapies have also shown promise in human clinical trials, but more research is needed. There is currently only one viral therapy approved for use in the U.S. and Europe.

What research is The Ottawa Hospital doing on viral therapy for cancer?

Researchers at The Ottawa Hospital and colleagues have discovered and developed several viral therapies for cancer, including MG1-MAGEA3, which is currently being tested in clinical trials. MG1-MAGEA3 was jointly developed by Dr. John Bell (The Ottawa Hospital, University of Ottawa), Dr. David Stojdl (Children’s Hospital of Eastern Ontario, University of Ottawa) and Dr. Brian Lichty (McMaster University) and their respective research teams and colleagues.

MG1-MAGEA3 uses two engineered viruses. One is derived from a virus called Maraba that was first isolated from Brazilian sandflies. The other is derived from a common cold virus called adenovirus. Both of these viruses have been engineered to stimulate an immune response against cancer cells that express a protein called MAGE-A3. The Maraba virus also achieves an extra layer of anti-cancer activity by replicating inside many kinds of cancer cells and killing them directly.

MG1-MAGEA3 is being developed in partnership with Turnstone Biologics, a company co-founded by Drs. Bell, Stojdl and Lichty.

I have cancer. How can I try MG1-MAGEA3 viral therapy?

The MG1-MAGEA3 viral therapy is not available as a standard treatment. It is only available through clinical trials at a small number of hospitals. These trials can only enroll a small number of patients with specific kinds of cancer at specific stages of disease. This means most people with cancer will not be able to participate.

If you are a patient currently being treated at one of the participating hospitals, you can ask your cancer specialist about enrolling in one of these trials.

IND.214 Trial: MG1-MAGEA3
  • Types of cancer being treated: Lung, Breast, Esophageal
  • Eligibility criteria, participating hospitals and other details on
  • Media release

Sandpiper Trial: MG1-MAGEA3 with immunotherapy drug pembrolizumab

Trial sponsor Turnstone Biologics can also answer questions at 613-421-8930, ext. 400.

Do we know any results from trials of MG1-MAGEA3?

We will release the results after each trial is completed and published in a peer-reviewed journal or presented at a scientific conference.

Researchers from The Ottawa Hospital have been featured in media stories that have included images of human tumours shrinking after treatment with cancer-fighting viruses. These images are from patients in past trials with a different virus (not MG1-MAGEA3). These past trials have had successes in some patients, but no effect in others. More research is required to understand why some patients respond to viral therapies while others do not.

What about other viral therapies?

Many other viral therapies for cancer are being developed around the world. One of these, called Imlygic (also called talimogene laherparepvec or T-VEC) is available as a standard therapy for melanoma in the United States and Europe. We don’t know if or when this will become a standard therapy in Canada, however it is available through clinical trials at The Ottawa Hospital and other centres.

Your cancer specialist (oncologist) can provide more information about clinical trials of other viral therapies and other experimental treatments. You can also search for clinical trials on websites such as:

About The Ottawa Hospital

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.

Media contact

Jennifer Ganton
Director, Communications and Public Relations
Ottawa Hospital Research Institute
Office: 613-798-5555 x 73325