In a groundbreaking medical development, researchers in Toronto say an Ontario man living with HIV for nearly three decades has become the first Canadian and only the 10th person worldwide to be essentially cured of the virus following a rare bone marrow transplant.
The case, referred to by researchers as the “Toronto patient,” was presented last month at the Canadian Association of HIV Research Conference by experts from University Health Network and the University of Toronto.
According to researchers, the anonymous patient was first diagnosed with HIV in 1999 and had successfully managed the virus for years using anti-retroviral therapy, which suppresses HIV to undetectable levels but does not completely eliminate it from the body.
In 2021, the patient was also diagnosed with acute myelogenous leukemia, a serious form of blood cancer that required a bone marrow transplant as part of his treatment.
Doctors then conducted an international donor search to locate stem cells carrying a rare genetic mutation that naturally resists HIV infection. Researchers say only about one per cent of people of European ancestry possess this mutation.
The transplant procedure was performed at Princess Margaret Cancer Centre, one of Canada’s leading cancer hospitals.
Following the transplant, doctors observed a gradual disappearance of HIV-infected cells from the patient’s body. In July 2025, the patient stopped taking anti-retroviral medication altogether. As of April 2026, highly sensitive laboratory tests continue to show no detectable traces of HIV in his system.
Researchers currently describe the patient as being in sustained remission and say he could officially be considered cured if the virus remains undetectable for another two-and-a-half years.
Dr. Sharon Walmsley, director of the HIV Clinic at Toronto General Hospital, called the case an important contribution to global HIV cure research.
“The small but growing number of these cases prove an HIV cure is possible,” Walmsley said, while cautioning that bone marrow transplants are not a practical cure for most people living with HIV because the procedure carries major health risks.
Experts note that bone marrow transplantation has a mortality risk of nearly 20 per cent and is generally reserved for patients already requiring treatment for life-threatening blood cancers such as leukemia.
Dr. Mario Ostrowski of St. Michael’s Hospital said researchers are now studying how the findings from this case may help develop safer and more accessible HIV cures in the future, particularly by targeting hidden viral reservoirs within immune cells.
The breakthrough comes as thousands of Canadians continue to live with HIV. According to federal statistics, more than 65,000 Canadians were living with HIV by the end of 2022, while over 2,400 new diagnoses were recorded in 2023.
Medical experts also stress that despite enormous progress in treatment, stigma surrounding HIV remains a major challenge for many patients.
Advocates have increasingly promoted the global “Undetectable = Untransmittable” (U=U) campaign, which confirms that individuals with HIV who maintain undetectable viral levels through treatment cannot sexually transmit the virus to others.
Researchers say the Toronto case represents not only a major scientific milestone for Canada, but also renewed hope in the global search for a long-term cure for HIV.