Potential HIV cures and the advent of long-acting HIV treatment, delivered via subcutaneous injection, slow-release patch, or even a pill, were among the biggest findings revealed at this year's virtual Conference on Retroviruses and Opportunistic Infections.
In a Facebook live video, Drs. Hillary Hoffman and Carl Dieffenbach from the National Institutes of Health described CROI's big takeaways. Dieffenbach started with the event's plenary discussion, which centered on upcoming prevention options, especially for women. Aside from Truvada (the first drug approved for use as PrEP) and vaginal rings, long-acting prevention options delivered via injectables were seen as successful in recent studies. The positive prevention results were mostly the result of increased adherence with injections of cabotegravir, which is being studied as a prevention option. Cabotegravir was recently approved by the Food and Drug Administration in combination with rilpivirine for the treatment of HIV (sold as ViiV Healthcare's Cabenuva). Depending on potency and scientific advances, injections of cabotegravir could be effective for a month, two months, six months, or even a year, freeing people with HIV — and those hoping to remain HIV-negative — from adhering to a daily pill.
"Incredibly effective and good adherence throughout the study," Dieffenbach said of cabotegravir's prevention power. Dieffenbach cited a study of about 4,500 participants; of those taking Truvada, 38 individuals became HIV-positive, compared with 12 given cabotegravir.
Hoffman and Dieffenbach also discussed COVID-19 and how research on that disease might yield advances for HIV. "Can [COVID] antibodies be used in HIV prevention?" Dieffenbach posited. "Can we get to a long-acting antibody that could either be used independent of a medication for the treatment or prevention of [HIV]?"
An antibody "cocktail" administered either as a pill or injectable could "allow people to live their truths of U=U [undetectable equals untransmittable] but not have to take a pill a day," Dieffenbach said, "and I think that the ultimate goal of where we want to go with therapy in the next few years."
Dieffenbach was impressed with lenacapavir, Gilead Sciences' potential HIV inhibitor, calling it "pretty amazing." Injected under the skin and effective for six months, the drug is aimed at reducing viral loads of HIV-positive people suffering from drug resistance.
"It's really exciting and gratifying to see something coming forward that was so strong and so safe for that population that could also be an anchor for prevention and other treatment," Dieffenbach said. "We are not done in the drug discovery and development space in HIV; there's always room for improvement. We're getting to a point where treatment is accessible and easy for all. Some people just can't take a pill a day. We need to meet their needs."
Hoffman took a question from an online participant who asked why the new injectables require a visit to a clinic or doctor's office. Dieffenbach said we're a ways off from offering injectable treatment or prevention that's available for self-administration, like insulin, but even the required clinic visits are a step up from a requirement of daily medication, according to Dieffenbach.
At this year's CROI, more data was also uncovered on the IMPAACT 2010 study, which focused on pregnant women with HIV. Dolutegravir — previously seen as risky for pregnant women in preventing perinatal HIV transmission — was shown to be successful, including when paired with tenofovir alafenamide (F/TAF). The combination was shown as especially beneficial to controlling outsize weight gain (or loss) among expectant mothers with HIV.
"There were also some really interesting talks in the cure space... that give glimmers of hope," Dieffenbach added. "We're beginning to really understand the dynamics of the [HIV] reservoir in different ways."
The doctor expressed hope at research into elite controllers — people with HIV whose viral loads remain low even without the aid of antiretrovirals — and the increasing research into "how their [HIV] reservoirs look different than those who are virally suppressed [through medication]."
Check out Hoffman and Dieffenbach's discussion below.