An eighth person—and second woman—appears to be cured of HIV after a stem cell transplant for cancer treatment, according to a poster presented at the 2024 HIV Drug Therapy conference in Glasgow. The woman, who was treated for leukemia in France, received stem cells in July 2020 from a donor with a rare mutation that prevents the virus from entering cells. Although she stopped antiretroviral treatment in October 2023, she has not experienced viral rebound. Researchers have found no HIV RNA or DNA in her circulating CD4 cells or blood plasma, and her HIV antibody levels have declined.

 

Only a small number of people have been cured after donor stem cell transplants, and scientists are still trying to figure out why. Five people—including the latest patient—received stem cells from donors with two copies of the CCR5-delta32 mutation. One received cells with a single copy, one received a mix of cells with and without the mutation, and one person’s donor had “wild-type” stem cells with no copies. Some underwent intensive pretransplant conditioning chemotherapy and radiation, while others received gentler regimens. Some experienced severe graft-versus-host disease, which occurs when donor immune cells attack the recipient’s body, but others did not. The size of the preexisting viral reservoir and individual immune response may also play a role.

 

The risky and expensive transplant procedure is appropriate only for HIV-positive people with advanced cancer, but each new case offers clues that could help scientists develop a more widely applicable functional cure. “We need to give people hope but make it realistic,” says HIV cure expert Sharon Lewin, MD, PhD, of the Peter Doherty Institute at the University of Melbourne.