Clinical trials of a new form of long-acting pre-exposure prophylaxis for HIV, commonly known as PrEP, have launched in the US. As well as hopefully leading to a new option for HIV prevention, the trials are aiming to address an unmet need in HIV research by focusing on two populations that have often been passed over: cisgender women and people who use injectable drugs.
The introduction of PrEP represented a great step forward in the continuing fight against HIV. When taken as prescribed, it reduces the risk of catching HIV through sex by 99 percent, and through injecting drugs by 74 percent.
PrEP generally takes the form of a pill that you need to take every day to be sure of maximum protection. In 2021, the Food and Drug Administration (FDA) approved an injectable form of PrEP that is only administered every two months, but that’s not available everywhere yet.
The new type of PrEP that’s currently under clinical trials has been developed with the aim that the injection will only have to be given every six months, which could make it more convenient and accessible for some people. It uses a drug called lenacapavir, which is already FDA approved for use in treatment-resistant HIV.
The trials, based out of the University of California San Diego Antiviral Research Center, are currently recruiting participants from two populations that have historically been underrepresented in HIV studies: cisgender women (those whose biological sex is female and whose gender identity aligns with this), with a particular focus on Black and Latina participants; and people who currently inject drugs, including opioids and cocaine.
These populations account for 18 percent and 7 percent of new HIV diagnoses in the US respectively, according to a statement from the National Institutes of Health (NIH). While much of the research up to now has focused on men who have sex with men – who accounted for 70 percent of new HIV infections in 2021 according to HIV.gov – there have been calls in recent years for trials and investigations to be more representative of the diverse groups that are affected by this virus.
The studies will take place at sites across the US, enrolling people who meet the inclusion criteria and who could benefit from taking PrEP. Participants will randomly be assigned to receive the new lenacapavir injections or an oral PrEP formulation that’s already approved for use. The researchers will focus on safety, how the drug works in the body, and whether the participants experience side effects.
The outlook for people newly diagnosed with HIV has come a very long way in the last 50 years. Awareness of safe sexual practices has helped unknowable numbers of people avoid infection, and advances in antiretroviral treatments have meant that reducing someone’s viral load to undetectable – which also means they can no longer pass the infection on – is a realistic goal for many. The more recent introduction of PrEP gave at-risk people another way to protect themselves from becoming infected.
It will be some time before we see any results from these trials; but, if they’re successful, it could herald an even more accessible means of preventing HIV infection, as well as bolstering scientific knowledge about groups of people who are all too often left out of the conversation.
