On Jul. 27, 2022, City of Hope announced that a 66-year-old man who was diagnosed with HIV in 1988 had been in remission from the virus for over 17 months after stopping antiretroviral therapy (ART) for the disease following a stem cell transplant from an unrelated donor for acute leukemia.

The man lived with HIV for over 31 years, the longest of any of the three previous patients with HIV who have gone into remission after receiving a stem cell transplant for a blood cancer and HIV. At 63 years old at the time of his transplant, he is also the oldest patient with HIV and blood cancer to undergo a transplant and achieve remission from both conditions.

Following the development of a form of leukemia more prevalent in those with HIV later in life — acute myelogenous leukemia — the man received the life-saving stem cell transplant in early 2019 from a volunteer stem cell donor who had a rare genetic mutation, the homozygous CCR5 delta 32 mutation, that makes people resistant to most strains of HIV infection. CCR5 is a receptor on CD4+ immune cells, and HIV uses that receptor to enter and attack the immune system. But the CCR5 mutation blocks that pathway, which stops HIV from replicating.

In addition, the patient was able to receive a less intensive pre-transplant chemotherapy regimen that City of Hope and other transplant programs have developed for older and less fit patients prior to transplant. This regimen makes an allogeneic transplant — a transplant from donor cells — possible in order for this patient population to achieve remission from their cancers. While still effective, it is better tolerated by older patients, thus reducing the potential for transplant-related complications.

Since recovering from his transplant, the City of Hope patient has not shown any evidence of having replicating HIV virus in his body, either in blood or tissue samples. With institutional review board approval, he stopped taking ART for HIV in March 2021 and was monitored closely for rebound virus. He might have been able to stop the therapies sooner, but wanted to wait until he was vaccinated against COVID-19. City of Hope is continuing to monitor the patient on an ongoing basis.