Josep Mallolas

Stem cell transplants in cancer patients have achieved complete remission of HIV in a few cases in people who are also HIV-positive. However, in most cases, the donors were homozygous—with two identical copies of the gene—for a mutation in the CCR5 gene that is considered protective against the virus. A German team has now reported a new case of remission in a 60-year-old man with leukemia—called the “second Berlin patient”—in which the donor was heterozygous (only one of the two copies contained the mutation), which could broaden the alternatives. The results are published in the journal Nature.

Antiretroviral therapy has become a vital treatment for people with HIV. However, it is not a cure, because the virus is able to take refuge and hide in certain blood cells. Now, a study of 65 people—30 women and 35 men—who were undergoing this therapy has found that women's immune systems tend to be more effective at controlling the virus. According to the researchers, who published their findings in the journal Science Translational Medicine, the study ‘reinforces the importance of considering sex in the design and implementation of medical interventions aimed at cure and suggests that women may be better candidates for exploring innate immunity-dependent strategies.’

Science magazine has named lenacapavir as breakthrough of the year. Lenacapavir is an injectable drug that prevents HIV infection for six months with near 100% efficacy. The publication notes its potential to dramatically reduce infections in high-risk populations, but also reminds that global roll-out will depend on affordability, manufacturing agreements and a robust health infrastructure. Approval of the drug is expected by 2025. 

The Science group is simultaneously publishing four papers (two in the journal Science, one in Science Immunology and one in Science Translational Medicine) that include advances in a sequential vaccination strategy for an effective HIV vaccine. The methods employed aim to obtain broad-spectrum neutralising antibodies and one of the proposals is already in clinical trials. 

Pre-exposure prophylaxis (PrEP), which usually consists of taking a daily oral anti-HIV drug, is a highly effective measure to prevent HIV infection. However, it only works well if people strictly follow the protocol, and some people end up not adhering to it. To improve this situation, researchers have tested an implant under the skin of non-human primates that releases the antiretroviral drug islatravir and maintains adequate concentrations for at least 20 months. The results, published in the journal Science Translational Medicine, show complete protection against infection with repeated exposure.

A virological and immunological follow-up confirms that a third patient has been cured of HIV nine years after receiving a bone marrow transplant for myeloid leukaemia, and four years after stopping his antiretroviral treatment. This case of the Düsseldorf patient, similar to two previously documented in Berlin and London, is detailed in a Nature Medicine publication by an international consortium coordinated by the IrsiCaixa AIDS Research Institute and the University Medical Center in Utrecht, the Netherlands. The patient was diagnosed with HIV in 2008 and in 2011 with leukaemia, for which he received the transplant in 2013.