A 62-year-old Toronto man has shown no detectable signs of HIV in his body since stopping his medication in July 2025, making him a strong candidate to become the eleventh person in the world considered cured of the virus.
His case was presented in April 2026 at the Canadian Association of HIV Research Conference, drawing attention from scientists and advocates around the world.
The man, known publicly only as the “Toronto patient,” was first diagnosed with HIV back in 1999.
He had been managing his infection with antiretroviral therapy (ART) for over two decades, the same daily medication regimen that millions of people living with HIV depend on to keep the virus under control.
Then, in 2021, he was diagnosed with something far more immediately threatening: Stage 4 Burkitt lymphoma, a rare and aggressive blood cancer that had spread to his brain and lymph nodes.
Doctors gave him less than six months to live.
What happened next was extraordinary.
To treat the cancer, doctors at the University Health Network’s Princess Margaret Cancer Centre in Toronto performed a bone marrow stem cell transplant.
But this was no ordinary transplant.
They searched a global donor registry and identified a matched donor who carried two copies of a rare genetic mutation known as CCR5-delta-32, which disables the very receptor that HIV uses to enter and infect human immune cells.
In November 2021, the transplant took place.
The cancer went into remission.
And, almost as a side effect, so did his HIV.
As of April 2026, according to University Health Network, his HIV levels remain completely undetectable using even the most sensitive laboratory tests available.
If he stays that way through approximately the end of 2027, he will officially join a tiny group of people in the world considered cured of HIV.
“This person now has an immune system that cannot be affected by HIV,” said Professor Sharon Walmsley, director of the HIV clinic at the University of Toronto’s University Health Network, in a statement reported by Global News.
“He is quite amazed by all of this. When we told him that we believe him to be cured, he was pretty astounded.”
How the Study Was Conducted
The Toronto patient’s case unfolded over a period of nearly five years.
When he was diagnosed with Burkitt lymphoma in 2021, his medical team faced a dual challenge: saving his life from an aggressive cancer while managing his longstanding HIV infection.
The decision was made to pursue an allogeneic hematopoietic stem cell transplant, a procedure in which healthy stem cells from a donor are used to rebuild a patient’s blood and immune system after their existing cells are destroyed through chemotherapy.
The critical step was finding the right donor.
His doctors conducted an international search through a global bone marrow registry, specifically looking for a match who carried two copies of the CCR5-delta-32 mutation.
That mutation is found in roughly one to two percent of people of European descent, making compatible matches rare and difficult to locate.
Once a donor was found, the transplant was performed at the Hans Messner Allogeneic Transplant Program at Princess Margaret Cancer Centre.
The conditioning regimen used was reduced-intensity, meaning the chemotherapy used to prepare his body for the new cells was less aggressive than standard protocols, intended to reduce the risks associated with the procedure.
Following the transplant, researchers at St. Michael’s Hospital, led by Professor Mario Ostrowski, began closely monitoring the patient’s HIV DNA levels in his blood cells.
Over the following years, they observed a steady and continuous decline.
By July 2025, four years after the transplant and with the cancer firmly in remission, the medical team made the decision to stop his antiretroviral medications entirely.
It was a nerve-wracking moment.
His most recent lab tests before stopping ART had detected a single cell containing a complete HIV genome.
“Let’s go for it!” Dr. Walmsley recalled him saying, as reported by The Globe and Mail.
Ten months later, HIV remains undetectable.
Findings From the Study
The results reported at the Canadian Association of HIV Research Conference in April 2026 were striking.
HIV was completely undetectable in the Toronto patient’s blood using highly sensitive laboratory testing, the same level of sensitivity used in other internationally recognized cure cases.
Researchers also found no HIV-specific immune responses, a finding that suggests the virus is not simply hiding in the body but may have been genuinely eliminated.
According to the UHN press release, “no HIV-specific immune responses have been detected, a finding consistent with cases considered cured internationally.”
The progressive decline in HIV DNA that Professor Ostrowski’s team tracked over five years supports the conclusion that the latent viral reservoir, the hidden pool of infected cells that normally makes HIV impossible to eradicate with standard treatment, has been dramatically reduced or wiped out entirely.
The recovery, however, was not without serious complications.
The Toronto patient developed graft-versus-host disease, a condition in which the donor’s immune cells recognize the recipient’s body as foreign and begin attacking it.
He also experienced febrile neutropenia, acute kidney injury, multiple infections, and a fractured hip during his recovery.
Graft-versus-host disease is a common and potentially life-threatening complication of stem cell transplants.
Interestingly, though, scientists believe this same immune response may have played a role in clearing his HIV reservoir, by attacking and destroying the cells that harbored the latent virus.
The transplant has effectively given him a new immune system built from donor cells, one that is genetically resistant to HIV.
“The small but growing number of these cases prove an HIV cure is possible,” Professor Walmsley said.
“Cases such as these provide important information for researchers to find ways to eradicate HIV from the body.”
But Here Is What Most People Get Wrong About This Cure
When news breaks about someone being cured of HIV, the instinct for many people is to wonder: why isn’t everyone with HIV getting this treatment?
It is a completely understandable question.
The short answer is that this procedure is not designed to cure HIV.
It is designed to treat cancer.
The bone marrow transplant was performed because this man had a life-threatening blood cancer, not because his doctors were attempting to cure his HIV infection.
The HIV cure was, in medical terms, a remarkable bonus.
And here is the harder truth: stem cell transplants of this kind carry a 10 to 20 percent risk of death from complications, according to estimates cited by CBC News.
More recent research has put that figure somewhat lower, but it remains a serious and invasive procedure.
For someone living with HIV who does not also have cancer, there is no medical justification for taking on those risks.
Modern antiretroviral therapy has transformed HIV from a fatal diagnosis into a manageable chronic condition.
People on ART can live near-normal lifespans.
Globally, according to UNAIDS, approximately 40.9 million people were living with HIV in 2025, and around 88 percent of them knew their status.
Among those who knew they were positive, 89 percent were accessing treatment.
That is a medical achievement worth celebrating, even as scientists continue searching for something more permanent.
So while the Toronto patient’s story is genuinely historic, it does not represent a treatment that is coming soon to a clinic near you.
What it does represent is proof of concept.
How This Applies to Real Life: What the Science Is Actually Telling Us
The significance of this case and the ten others like it lies not in opening a new treatment pathway for the general HIV-positive population.
It lies in what these cases teach scientists about how HIV actually hides in the body and how it can be defeated.
HIV’s greatest trick is its ability to go latent.
When someone stops taking antiretroviral medication, the virus typically rebounds within weeks because it has been hiding in long-lived memory immune cells, waiting.
Finding a way to flush out that reservoir without a risky transplant is the central challenge of HIV cure research.
Each successful case, including the Toronto patient, gives researchers a clearer map of what conditions are needed for the reservoir to be cleared.
The role of graft-versus-host disease, the importance of donor cell immunity, and the contribution of the CCR5 mutation are all factors being studied carefully.
The Genetic Key: What Is CCR5-Delta-32?
To understand why this works, it helps to understand the biology.
HIV enters human immune cells by latching onto a protein on the cell’s surface called CCR5, which acts like a door handle the virus uses to get inside.
The CCR5-delta-32 mutation removes that door handle entirely.
People who inherit two copies of this mutation from both parents have immune cells that HIV simply cannot enter.
The mutation is thought to have risen to its current frequency in European populations partly as a result of natural selection, possibly offering some protection against bubonic plague centuries ago, according to research published in the Proceedings of the National Academy of Sciences.
Today, only about one percent of people of European descent carry two copies of the mutation, making compatible donors for these transplants genuinely rare.
When a patient receives a bone marrow transplant from such a donor, their immune system is rebuilt using the donor’s HIV-resistant cells.
Over time, if the transplant succeeds, the patient’s entire blood and immune system is replaced by cells that HIV cannot infect.
The Bigger Picture: Ten Others Came Before Him
The Toronto patient would not be starting something new if confirmed.
He would be joining a club of ten others who have already achieved long-term HIV remission or cure through a similar process.
The first was Timothy Ray Brown, known for years as the “Berlin patient,” who received a stem cell transplant in 2007 and remained HIV-free without medication until his death from leukemia in 2020.
After Brown, progress was slow.
Then came Adam Castillejo, the “London patient,” confirmed cured in 2020.
Since then, cases have been reported from Düsseldorf, New York, Marseille, Chicago, and Oslo, among others.
Each case has expanded researchers’ understanding.
Notably, a December 2025 study published in Nature described a patient who achieved sustained HIV remission after a transplant from a donor who carried only one copy of the CCR5-delta-32 mutation, not two, challenging the assumption that two copies were strictly necessary.
That finding opens the possibility that donor pools for future research may be larger than previously thought.
Why This Still Matters Even If You Will Never Have This Transplant
Forty point nine million people are living with HIV worldwide right now.
Most of them will never be candidates for a bone marrow transplant.
But the research generated by cases like the Toronto patient’s has direct value for all of them.
Understanding how the viral reservoir is cleared, how donor immune cells contribute to eliminating latent virus, and what role genetic factors like CCR5 play could eventually help scientists develop a functional cure accessible to the broader HIV-positive population, whether through gene therapy, immunotherapy, or some as-yet-undiscovered approach.
Researchers are already exploring CRISPR-based gene editing to replicate the CCR5-delta-32 mutation in a patient’s own stem cells, a method that could theoretically eliminate the need for a donor match altogether.
“The small but growing number of these cases prove an HIV cure is possible,” as Professor Walmsley said.
That word, “possible,” carries enormous weight when you consider that in 1983, when Walmsley was a medical intern and stood at the bedside of one of Toronto’s first AIDS patients, the virus did not even have a name yet.
She went home that night in tears.
Four decades later, she is telling a 62-year-old man in Toronto that she believes he may be cured.
What Comes Next for the Toronto Patient
The next benchmark is clear.
If the Toronto patient remains in sustained remission through approximately the end of 2027, which would be roughly two and a half years after stopping antiretroviral therapy, his doctors will formally consider him cured.
As of April 2026, he is on track.
He is being monitored closely by Professor Ostrowski’s team at St. Michael’s Hospital and Dr. Walmsley’s clinic at University Health Network.
No HIV-specific immune activity has been detected, meaning his immune system is not even mounting a defensive response against the virus anymore, consistent with the possibility that the virus is simply no longer present.
The road ahead still involves waiting, monitoring, and hoping that the numbers continue to hold.
But in the meantime, the Toronto patient himself seems to be doing just fine.
When told he may be cured, he was, in his doctor’s words, “pretty astounded.”
And honestly, given where medicine was in 1983, the rest of us should be too.
References and Further Reading
University Health Network: Toronto Man in HIV Remission After Bone Marrow Transplant
aidsmap: Toronto man cured of HIV after stem cell transplant
UNAIDS: Global HIV & AIDS Statistics Fact Sheet
Nature: Sustained HIV-1 remission after heterozygous CCR5Δ32 stem cell transplantation
