LONDON – A London man infected with HIV may be the second person to beat the virus that causes AIDS, researchers reported, a finding advancing the costly and challenging search for a cure.
Nearly three years after the man received a stem-cell transplant from a donor who was genetically resistant to HIV, extensive testing shows he has no detectable amounts of the virus, according to the research, published in the journal Nature on Monday.
“He’s doing well,” said Ravindra Gupta, HIV researcher at University College London who led the study.
He has been off antiretroviral drugs for about 18 months. Those drugs keep HIV, the virus that causes AIDS, in check.
If the man, whose name the research team didn’t disclose, continues to remain free of the virus, he would become only the second patient to be cured of the human immunodeficiency virus. The first, Timothy Brown, known as the “Berlin Patient,” was cured about a decade ago, following a stem-cell transplant.
This new case shows that the cure of the Berlin patient wasn’t an anomaly and provides new impetus to develop treatments based on the transplants given to both patients, Dr. Gupta said.
“Having another proof of concept with the same approach is important,” he said.
Researchers tried to cure several other patients in the years following Brown’s successful transplant, but they failed.
Scientists are struggling to find a cure for HIV, a virus notorious for hiding in the body and evading attempts to flush it out.
Nearly 37 million people have been infected world-wide over the past four decades.
While more than 21 million take drugs that keep them alive and reduce the spread, an estimated 1.8 million people were newly infected in 2017.
“When you have a single case report in medicine, you never know if this is just an unusual set of circumstances,” said Sharon Lewin, director of the Peter Doherty Institute for Infection and Immunity at the University of Melbourne and Royal Melbourne Hospital, and co-chair of the International AIDS Society’s Towards an HIV Cure initiative. “The fact that it has now been repeated is really very exciting. It does demonstrate that a cure is possible.”
But the approach couldn’t be applied to the millions of people with HIV, she and other HIV experts stressed. It is risky and costly. Both men had diseases that warranted stem-cell transplants; Brown had leukemia and needed a transplant. The “London patient” had Hodgkin lymphoma.
“It’s not a practical solution” for people who don’t have diseases that require a stem-cell transplant,” said Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, the National Institutes of Health arm that leads HIV research.
But he said, “The fact that you have a second patient says yes, it can be done.”
The London man, and Brown before him, both received stem-cell transplants from donors who had two copies of a key mutation to a gene called CCR5.
The vast majority of HIV strains use normal copies of this gene to gain entry to a patient’s immune-system cells.
Research has shown that the mutation renders that gene inactive, therefore preventing HIV from penetrating the cells.
People who inherit a CCR5 mutation from both parents don’t become infected with HIV even after intense exposure to the virus.
Less than 1 percent of people of European descent inherent both copies of the mutation; it isn’t believed to affect people from other regions.
The London patient received his stem-cell transplant in May 2016, Dr. Gupta said. He had been diagnosed with HIV in 2003, and Hodgkin lymphoma in 2012.
His treatment was less intense than Brown’s, because he didn’t require a second transplant, or radiation, Dr. Gupta said.
The patient went off antiretroviral drugs in September 2017 and has been in remission since then. That shows that remission is possible without the all-out intensive treatment given to Brown, Dr. Gupta said.
Dr. Gupta said he and the research team consider the London patient to be in remission; it is too early to say he has been cured, he said.
Indeed, other patients have been given experimental treatments and gone off HIV medication, only to have their infections rebound.
A baby in Mississippi who was given aggressive drug treatment just after birth relapsed more than two years after she was taken off HIV drugs.