Researchers led by Dr. Steven Deeks at the University of California, San Francisco, presented early results in Boston showing CAR-T cells developed by Caring Cross and described by Boro Dropulić can push HIV to undetectable levels in some people for months or years; voices like Dr. Hans-Peter Kiem at Fred Hutchinson Cancer Center and Andrea Gramatica of amfAR caution larger trials are needed to see if this can become a safe, scalable one-time intervention.
Scientists are borrowing a winning play from oncology and retooling it against HIV by supercharging a person’s own immune cells. The idea is straightforward: take T cells out, reprogram them to hunt HIV, give them armor against infection, and put them back in as living drugs that can patrol the body long term. It feels bold because CAR-T has transformed certain blood cancers and now researchers want that same potency against a virus that hides out and rebounds when treatment stops.
The study that grabbed attention reported a single infusion shut down measurable virus in two trial participants — one for nearly a year and another for nearly two years — without their usual antiretroviral meds. These are early-stage results presented at the American Society of Gene and Cell Therapy gathering in Boston and they come with the usual caveats: bigger, longer studies are required to know if this effect is durable and repeatable. Still, when HIV can linger in reservoirs and spring back, any sustained control off therapy is a notable signal.
CAR-T therapy works by engineering T cells to recognize and kill target cells, and researchers at the nonprofit drug developer Caring Cross added two deliberate features for HIV. Their cells are tuned to better find infected cells and are built with protections so the virus can’t easily infect the reinfused T cells themselves. Boro Dropulić explains that the built-in armor should let these cells multiply and persist, improving the chances they can keep HIV suppressed on their own.
In Deeks’ trial at UCSF, different dosing and preparatory strategies were tested and safety was a primary concern; no serious side effects were reported. The first three recipients showed no measurable response and went back on standard therapy, but six others received a modest chemotherapy preconditioning to make room for the new cells and outcomes differed. Of those, two had strong, prolonged suppression, a third had a brief response and returned to treatment, and the rest had limited effects, showing how variable the response can be in early human work.
“We find the fact that two people have had such a really sustained response provocative,” he said. “There is a real need for a one-and-done, safe and scalable cure … and this is one of the strategies that we’re pursuing.” Those words underscore the cautious optimism driving gene- and cell-therapy approaches that aim to free people from lifelong daily pills.
“This is certainly very fascinating that they’ve had this positive response,” said Dr. Hans-Peter Kiem, a gene therapy expert at Seattle’s Fred Hutchinson Cancer Center who wasn’t part of the new study. He cautioned that it will take additional research to prove if CAR-T really works. Experts outside the trial stress replication, longer follow-up and broader participant diversity before declaring a breakthrough.
Context matters: there are nearly 40 million people living with HIV worldwide and current antiretroviral drugs control the virus well when taken, but they are not a cure and access can be uneven. Researchers have chased other clues to a cure before, from rare genetic mutations that confer resistance to striking cases of remission after risky stem cell transplants for cancer. The CAR-T strategy stands out because it tries to enhance what our immune system already does, not replace it wholesale, and groups like amfAR are funding efforts to make these therapies less complex and easier to deliver.
Practical hurdles remain: manufacturing living drugs at scale, ensuring long-term safety, and confirming who stands to benefit most. The early hint that patients who started antiretroviral therapy soon after infection did better in the trial points to biology that might be easier to shift in people with smaller viral reservoirs. Researchers will need rigorous trials and years of follow-up to determine whether this is a path toward the kind of single-treatment cure that Deeks and others are pursuing.
