Two HIV Patients Appear to Have Beaten Virus, Offering Hope for Cure

Doctors caring for the man said they haven’t found any human immunodeficiency virus that can replicate in his body since he stopped antiretroviral drug therapy in March 2021 after a transplant of stem cells containing a rare genetic mutation that blocks HIV infection. He was given the transplant for leukemia, for which people with HIV are at increased risk. Details of his case were made public Wednesday and will be presented at a large international AIDS conference in Montreal that opens Friday.

He is the oldest of five patients thus far who appear to have rid their bodies of HIV after the risky procedure and had been infected the longest, since 1988, offering hope for a growing cohort of aging HIV patients, said Jana Dickter, an infectious disease doctor who cares for the man at City of Hope, a cancer research and treatment center in Duarte, Calif., in the Los Angeles area.

“He saw many of his friends and loved ones become ill and ultimately succumb to the disease and had experienced some stigma associated with having HIV,” she said. His success “opens up the opportunity potentially for older patients to undergo this procedure and go into remission from both their blood cancer and HIV.”

The woman in Spain still has HIV lying dormant in some cells in her body. But the amount is declining, and the virus isn’t replicating even though she stopped antiretroviral therapy more than 15 years ago, said Juan Ambrosioni, one of the doctors caring for her at the Hospital Clinic of the August Pi i Sunyer Biomedical Research Institute in Barcelona.

She was diagnosed with HIV at age 59 shortly after becoming infected and entered a clinical trial in which she received antiretroviral drugs as well as therapies to boost her immune system. After nine months, the antiretrovirals were stopped, Dr. Ambrosioni said.

Years of research finally revealed how she keeps her HIV naturally under control, he said: she has high levels of two types of immune cells that the virus normally suppresses and that probably help control viral replication, he said. Details of her case will be presented at the same conference. Both patients declined to be identified publicly.

The two cases “provide continued hope for people living with HIV and inspiration for the scientific community,” said Sharon Lewin, director of the Peter Doherty Institute for Infection and Immunity and a leader in HIV cure research who wasn’t involved in the studies.

The scientific discoveries come as the global HIV/AIDS response has encountered its biggest setback in years. The number of new HIV infections is rising in countries in Asia and the Pacific where they had been falling, and progress in eastern and southern Africa—where the bulk of HIV infections occur—slowed in 2021, according to data released Wednesday by the Joint United Nations Program on HIV/AIDS.

As a result, the number of new infections globally fell 3.6% in 2021, the smallest annual decline since 2016.

Covid-19, the Ukraine war, debt repayments for the world’s poorest countries and other factors are draining resources from programs to prevent new HIV infections and treat those with the virus, said Matthew Kavanagh, UNAIDS deputy executive director. “The last two years of crises have really blown the global AIDS response off track in a way that’s going to require aggressive action to get back to where we need to be,” he said.

Finding a cure for HIV is a major scientific challenge because even when reduced to low levels with medication, the virus can hide from the body’s immune system, going latent in certain cells. It can then roar back to life and start replicating.

So difficult is HIV to get rid of that researchers are often reluctant to declare patients cured even when they can’t find any sign of the virus. Some patients have relapsed. “We don’t use the term ‘cure’ lightly in the world of HIV,” said Dr. Dickter, who says her patient is in remission but that to call him “cured” will take “more time and data.”

Doctors caring for the woman in Spain consider her to have achieved a “functional cure,” meaning that the virus hasn’t been completely eliminated but is under control without medication. People with undetectable levels of virus can’t transmit HIV to sexual partners, according to studies.

Other research released Wednesday identified a series of steps by which HIV becomes latent in a rare type of immune cell, an important finding that could help guide scientists searching for ways to flush those viruses out of the body, HIV researchers said. It shows that drugs tried so far attack only part of that latency process, said Eli Boritz, an HIV cure research scientist who led the work at the Vaccine Research Center of the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health.

Transplants such as the one the Los Angeles-area patient received can’t be a cure for the 38.4 million people living with HIV globally, Dr. Lewin said. They are risky and expensive, costing hundreds of thousands of dollars depending on the procedure, and only for people who need them for a life-threatening disease such as cancer, she and other researchers say. But they say scientists who are searching for a cure are learning from them.

“There are fancy new gene editing methods emerging that might one day be able to achieve a similar outcome with a shot in the arm,” said Steven Deeks, a professor at the University of California, San Francisco who leads research for an HIV cure and wasn’t involved in the studies of the two patients.

Dr. Ambrosioni said findings from the woman in Barcelona could be used to develop a treatment that could be given more widely than transplants.

He said he and his colleagues hope to determine whether her control of her HIV is the result of genetic factors, the immune-boosting treatment she received in the trial, or both. If a treatment for others results from the findings, “that could be something you could scale up for many, many people,” he said.

Write to Betsy McKay at betsy.mckay@wsj.com