Rare HIV Remission Achieved in Toronto Patients Following Bone Marrow Transplantation

Summary:
A Toronto man has achieved long-term HIV remission after undergoing a bone marrow transplant for leukaemia using donor cells with a rare CCR5-Δ32 mutation, a development that could mark Canada’s first potential cure. Researchers from University Health Network, working with Unity Health Toronto and the University of Toronto, reported that the patient—who had lived with HIV for 27 years—has shown no detectable virus since stopping treatment in July 2025. While experts say such cases indicate that a cure may be possible, they caution that the procedure is high-risk and limited to patients with serious blood cancers, though it offers valuable insights for future HIV treatment strategies. 

A Toronto man who had been living with HIV for almost 30 years is now in long-term remission after undergoing a bone marrow transplant for leukaemia using a donor with a rare genetic mutation, a case that researchers say could represent Canada’s first possible cure.

Clinicians at University Health Network said the patient may become the 11th person worldwide considered cured of HIV after receiving a high-risk transplant that replaced his immune system with cells resistant to the virus. The case, conducted in collaboration with Unity Health Toronto and the University of Toronto, was presented at the Canadian Association of HIV Research Conference on April 25.

The patient had been diagnosed with HIV for 27 years before developing acute myelogenous leukaemia. He then received donor stem cells carrying the rare CCR5-Δ32 mutation, which blocks HIV from entering immune cells. After the transplant, researchers recorded a steady reduction in viral levels, and the patient stopped antiretroviral therapy in July 2025. As of April 2026, no HIV has been detected using highly sensitive tests, with no evidence of viral reservoirs or immune response, findings consistent with previously reported cured cases, according to UHN.

Lead researcher Dr. Sharon Walmsley noted that increasing such cases suggests an HIV cure is achievable, while emphasising that bone marrow transplants remain too dangerous for routine use outside cancer treatment. Physician-scientist Dr. Bo Wang also stated on X that the procedure effectively replaced the patient’s immune system with one that HIV cannot infect, and that he has remained virus-free for nine months without medication.

Doctors involved stress that while the procedure is complex, costly, and carries serious risks, it is only performed when treating life-threatening blood cancers. However, they say these rare outcomes provide valuable insight into future strategies for eliminating HIV reservoirs safely.