A team of researchers at the University of Calgary has developed a new form of immunotherapy they say could change how some solid cancers are treated, offering new hope to patients who have exhausted conventional treatment options. The experimental treatment, known as GCAR1, is a new type of chimeric antigen receptor T-cell (CAR T) therapy. It works by training a patient’s own immune system to recognize and destroy cancer cells. While CAR T-cell therapy has transformed the treatment of certain blood cancers, it has been far less successful against solid tumours. Researchers say GCAR1 is the first therapy of its kind to show strong promise in treating a rare form of solid cancer known as alveolar soft-part sarcoma. “This work reflects a close collaboration between the University of Calgary, Cancer Care Alberta and partners across the country, bringing discovery science and clinical expertise together at every step,” said Dr. Douglas Mahoney, director of the Riddell Centre for Cancer Immunotherapy at the University of Calgary’s Cumming School of Medicine. In Calgary, the therapy has been given to two Canadian patients through an early clinical trial. The first patient, Stéphanie Alain, lived approximately 18 months longer than doctors had initially expected. Researchers say information gathered during her treatment helped them better understand how to improve the therapy. The knowledge was used to treat a second patient, 55-year-old Calgary resident Kent B. “This clinical trial gave me hope. I was told there wasn’t anything more that could be done to treat my cancer. I saw several CT scans of my cancer. It had metastasized to my lungs. After the second therapy the scans showed that many of the tumours shrank, and some had disappeared,” said Kent. Dr. Mona Shafey, the hematologist overseeing Kent’s treatment at the Arthur J.E. Child Comprehensive Cancer Centre, said one tumour in his lungs shrank from more than 2.5 centimetres to less than one centimetre. Researchers caution the treatment remains experimental, and more patients will need to be enrolled in future clinical trials to determine how well it works and whether it can become a standard treatment. Still, the team believes the discovery could have implications far beyond sarcoma. Researchers are now studying tumour samples from treated patients and working to develop more advanced versions of the therapy. The project is part of the University of Calgary’s Living Medicine Initiative, which focuses on developing treatments that use cells, genes and other biological tools to fight disease.
