This Week in HIV Research: Injectable PrEP Shows Promise in New Study

This week, a study finds that injectable cabotegravir, an investigational integrase inhibitor, is well tolerated and shows promise as pre-exposure prophylaxis (PrEP). Another study finds that starting treatment on the same day as diagnosis increases retention in care and leads to lower viral loads a year later. And criminalizing drug use may actually hinder HIV prevention and treatment efforts. To beat HIV, you have to follow the science!

Injectable Cabotegravir Promising for HIV Prevention

The injectable integrase inhibitor cabotegravir (CAB) was well tolerated by people who are not living with HIV, according to a clinical trial presented at the 9th IAS Conference on HIV Science.

About 200 study participants took CAB or a placebo orally for four weeks, and then received either 600 mg or 800 mg injections of CAB or a placebo every eight or 12 weeks. Two-thirds of participants were women. Despite some injection site pain and reactions, the drug was generally well tolerated. Drug level monitoring suggested that a 600 mg injection every eight weeks provides sufficient levels of the medication.

Other trials currently underway are evaluating how well CAB injections work to prevent seroconversion. Should they prove successful, "people at risk of becoming HIV infected will have another option that they can use," said Myron Cohen, M.D., of the University of North Carolina at Chapel Hill in an accompanying press release.

Same-Day Treatment Start Increases Retention in Care

Starting HIV treatment on the same day a person is diagnosed yielded better retention in care and lower viral loads a year later than did a three-week gap between testing and beginning antiretrovirals, a clinical trial published in PLOS Medicine found.

More than 700 patients who tested positive for HIV at an outpatient clinic were randomized to one of two arms: immediate or standard treatment. Immediate treatment meant starting antiretrovirals on the day of the test, standard treatment required follow-up visits, with HIV therapy starting three weeks after testing.

After 12 months, 53% of those in the immediate arm had undetectable viral loads (< 50 copies/mL), compared to 44% in the standard arm. Similarly, 80% in the immediate group were still in care at that point, compared to 72% in the standard group.

Study authors caution that the trial was limited to one clinic in Haiti, but note that studies elsewhere have shown similar results. A related perspective observed that an HIV diagnosis also has psychological repercussions that need to be addressed, and that the way in which treatment is offered is just as important as when it is provided.

Criminalization of Drug Use Counterproductive for HIV Prevention Efforts

The majority of 106 studies evaluated for a systematic review suggested that criminalization of drug use negatively affects HIV prevention and treatment, The Lancet reported.

Laws that make the use of street drugs a crime were consistently related to higher levels of needle sharing and other behaviors that increase the risk of seroconversion. Two of the studies that were evaluated found that supervised injection facilities and wider use of syringe access programs did not increase drug injections. While one study found that imprisonment reduced injection drug use, it also observed higher rates of syringe sharing, which increases the risk of acquiring HIV.

Authors cautioned that most of the studies reviewed were from North America and Asia. They concluded that criminalization "of drug use has negative effects on HIV prevention and treatment among [people who inject drugs]" and noted that this conclusion is also supported by the recommendations of various global policy bodies.