A Brazilian man may be the first person to be "cured" of HIV after receiving an intensive experimental drug therapy.
The 34-year-old, who was diagnosed with HIV in 2012, is the first person to maintain long-term HIV remission after being given a year-long course of intensive anti-retroviral (ARV) drugs. The man received the treatment alongside four other patients but was the only one to have been “cured”.
The researchers, who unveiled their findings at this week’s virtual International Aids Society conference, warn that further analysis is needed.
The patient - only the third person ever to have been "cured of the disease" - was put on standard ARV treatment two months after his diagnosis and then enrolled on a clinical trial where he received standard ARTs as well as the HIV drugs dolutegravir and marivoc. He was also given nicotinamide, a form of vitamin B.
Nicotinamide fights part of the virus that infects cells and causes them to self destruct as well as activating the immune system.
The patient received the intensive therapy for a year and then was taken off treatment in March 2019. Since then he has been tested every three weeks and a year later he still has no detectable viral load or any antibodies.
Professor Sharon Lewin, an HIV and infectious diseases expert at the University of Melbourne who was not involved in the research, said the fact that the patient has no antibodies was significant.
“When someone is infected with a virus they make antibodies. And antibodies don’t budge, even when you’re on treatment and there’s no detectable viral load. But this showed he had no antibodies which is supportive of him being cured,” she said.
However, she added that it was important to remember that this was just one patient and the findings were being published as a case report rather than a full academic paper.
“It’s interesting, but it’s hard to know how significant it is when it’s just a single case. I’d also like to know what happened to the other patients,” she said.
Dr Ricardo Diaz of the University of Sao Paulo in Brazil, who led the study, said he was "trying to wake up the virus" and boost the immune system's ability to eliminate it once it's flushed out of hiding.
"We can't search the entire body, but by the best evidence, we do not have infected cells," Dr Diaz said.
"I think it's very promising. This patient might be cured," but it will take more time to know, he added.
The man was diagnosed with HIV in October 2012 and was then put on treatment just two months later. Patients who go on treatment soon after acquiring HIV can quickly bring their virus under control, said Prof Lewin.
“So it’s hard to work out whether this person had the virus under control because we don't know when he acquired HIV or whether the addition of extra ARVs and nicotinamide made a difference,” she said.
However, if this approach is shown to work in more patients it would be a significant breakthrough.
Currently, people with HIV have to be on treatment for the rest of their lives to suppress their viral load. The treatment is a functional "cure" as it means patients have undetectable levels of virus and cannot pass it onto others and can live long and healthy lives.
However, treatment is expensive, people need to take medication every day and drug resistance has started to develop.
“Everyone wants to find a way to allow someone to stop treatment safely. If even three out of 20 patients had the same response to this treatment it would be exciting,” said Prof Lewin.
This is not the first time scientists have claimed to have found a way of eradicating the virus.
The first talk of an HIV “cure” was in 2007 when Timothy Brown - dubbed the Berlin Patient - underwent a bone marrow transplant to treat leukaemia. More than 10 years later he remains free of the disease.
The second person to be “cured” of the disease was Adam Castillejo, who made headlines last year as the "London Patient".
Mr Castillejo, who chose to waive his anonymity in March as he wanted to be an “ambassador of hope”, was treated with stem cells from a donor with genetic resistance to the disease by specialists at University College London and Imperial College in 2016. Since then he has shown no sign of the virus.
Deborah Gold, chief executive of National AIDS Trust, said the latest research was interesting.
“The results from one of the participants could lead to promising developments in finding a cure for HIV. Knowledge is key in ending HIV and we praise the work being done by researchers around the world to improve our knowledge and understanding about HIV.
“However, whilst work continues to explore the implications of this isolated case, we must remain focused on the tools we already have to stop acquisition of HIV.
“We can prevent HIV acquisition by improving access to the highly effective HIV prevention drug PrEP. Modern HIV treatment means people living with HIV can live healthily into old age, and once on effective HIV treatment cannot pass on the virus. Our focus in the UK and internationally must therefore be to provide easy access to PrEP and HIV testing, and universal access to free HIV treatment.”