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2mo ago

Toronto Patient’s HIV Is Undetectable After CCR5 Stem-Cell Transplant

Doctors stopped his HIV drugs in July 2025, with cure status to be judged after about two and a half years of continued remission.

Image
Dr. Sharon Walmsley, Senior Scientist, Toronto General Hospital Research Institute, in a clinic room at Toronto General Hospital on April 20, 2026. Walmsley, along with other medical professionals is researching HIV infection and a possible cure for those infected. (Fred Lum/The Globe and Mail)
Dr. Sharon Walmsley, HIV Clinic Director at UHN's Toronto General Hospital and Speck Family Chair in Emerging Infectious Diseases poses for a photograph in Toronto on Monday, April 20, 2026. THE CANADIAN PRESS/Nathan Denette
This image shows a scanning electron micrograph of multiple round bumps of the HIV-1 virus on a cell surface.

Overview

  • The Toronto patient’s virus remains undetectable following a 2021 bone marrow transplant using donor cells with a rare CCR5-Δ32 mutation.
  • His care team says he is in sustained remission and potentially cured, though they are waiting for a longer period off therapy before declaring a cure.
  • The donor’s mutation prevents the CCR5 receptor from forming on immune cells, which blocks HIV from entering and may help wipe out lingering infected cells.
  • The transplant was done to treat acute myelogenous leukemia, and the patient faced expected risks such as pneumonia, underscoring that this approach is not a routine HIV treatment.
  • If remission holds for about two and a half years after stopping antiretrovirals, he could join a very small group worldwide considered cured, informing research on safer, scalable strategies.