At the Conference on Retroviruses and Opportunistic Infections (CROI 2023) in February, many researchers presented studies looking at new drugs being tested for use as treatment, pre-exposure prophylaxis (PrEP), and post-exposure prophylaxis (PEP). Here are some highlights.
Lenacapavir given alongside broadly neutralising antibodies (bnAbs) may offer a twice-yearly treatment option. In this new study, 90% of people who received injections of lenacapavir (Sunlenca) plus infusions of two long-acting bnAbs had an undetectable viral load six months after stopping their existing antiretroviral therapy.
A promising new PrEP method has undergone its first safety study for anal sex. The insert (suppository) contains elvitegravir and tenofovir alafenamide (TAF) and is designed to be used for PrEP or PEP. It’s inserted into the vagina or rectum and dissolves within a few hours. The study found that the insert was safe to use and produced drug levels in rectal tissue that were well above protective levels for over a day.
There was some good news for women with regard to PrEP, as a study found that quarterly dosing may work. The research showed remarkable efficacy for cabotegravir used as PrEP in cisgender women. It found that most women would still have protective drug levels up to 14 weeks after their last injection.
Researchers have found that the white blood cell changes seen in people taking the new antiretroviral drug islatravir do not lead to a higher risk of infections. They found that despite a reduction in lymphocytes (a type of white blood cell), there was no difference in the rate of infections or COVID-19 in people taking islatravir. The study also found that the combination of doravirine and islatravir is just as effective as existing treatment in maintaining viral suppression.
Two separate studies have found that experimental islatravir implants protected monkeys against an HIV-like virus. It’s hoped that the implants, which are inserted under the skin and release islatravir over time, could be used as a way to deliver PrEP in the future. Both of the implants studied protected female macaque monkeys against vaginal infection with SHIV – a virus similar to HIV. One of the implants also protected male monkeys against rectal infection.