Hopes have been raised of a cure for AIDS after a patient in London became free of the HIV virus following a bone marrow transplant.
Although it is not a viable large-scale strategy for a cure … these new findings reaffirm our belief that there exists a proof of concept that HIV is curable
Anton Poziak, president, International AIDS Society
The so-called ‘London Patient’ – who has not disclosed his identity – is the second person ever to be ‘cured’ of HIV, following Timothy Brown (the ‘Berlin Patient’) who underwent a similar bone marrow stem cell transplant to treat cancer in 2008. Brown went public in 2010, stating that, “I didn’t want to be the only person cured… I wanted to do what I could to make [a cure] possible. My first step was releasing my name and image to the public.”
Both patients received stem cells from a donor with a rare genetic mutation of the CCR5 gene, which made them resistant to HIV. Brown stopped taking the antiretroviral drugs that suppress HIV shortly after his treatment and has been virus-free since that point, while the London Patient stopped taking antiretrovirals 18 months ago, with no sign of a return of HIV.
Although the procedure offered to the London and Berlin patients can never be offered as a cure for HIV due to the risks inherent in stem cell transplants, some experts are speculating that this represents a seismic moment in the quest to find a cure for the disease. Anton Poziak, president of the International AIDS Society, said, “Although it is not a viable large-scale strategy for a cure … these new findings reaffirm our belief that there exists a proof of concept that HIV is curable.”
The way forward may lie in gene editing, according to Prof Ravindra Gupta of University College London, the lead author of the paper on the successful treatment of the London Patient. Although the Chinese scientist who edited the genes of babies in the womb to make them resistant to HIV was globally condemned for putting his patients at risk, Gupta feels that the end justifies the means in editing the CCR5 gene in HIV patients. He noted that “this is a bonafide research target and probably the most promising we have for an HIV cure.”
Despite millions of people now living well on antiretroviral drugs, Gupta asserts that this will put a significant strain on healthcare systems across the globe in years to come, especially in poorer nations. “There are 36 million-odd people with HIV worldwide,” he noted. “The aim is to get everybody on treatment for the rest of their lives and that’s a huge undertaking both for drug delivery but also making sure people can stay on medication for decades. There is a cost issue for developing countries.”