Swapping daily pills for monthly shots could transform HIV treatment and prevention

New results are raising hopes for easing one challenge of living with HIV: the need to take daily pills for life, both to ward off AIDS and to lower the risk of transmitting the virus to others. Missing doses can also foster the emergence of HIV strains with drug resistance, a danger both to the person receiving treatment and, if those strains spread, to entire populations. Now, a large-scale study has shown over 48 weeks that monthly injections of two long-acting anti-HIV drugs work just as well as taking daily pills.

ViiV Healthcare, a London-based collaboration between GlaxoSmithKline and Pfizer, revealed the highly anticipated findings in a press release on 15 August. This shareholder announcement, required by regulatory agencies to inform investors, offered scant data. But it was welcome news to other researchers studying long-acting anti-HIV medication schemes—and to clinicians who think they could transform both treatment and prevention of HIV infections.

Anton Pozniak, an HIV/AIDS clinician at Chelsea and Westminster Hospital in London, says long-acting injections could help HIV-infected people who have "pill fatigue," difficulty swallowing the medication, or psychological issues that make it hard to cope with a daily reminder that they have a deadly virus. He calls the results "a fantastic development" but adds, "We still have a way to go." Even if these injectables win regulatory approval, many practical questions remain about their cost, the impact of missing shots, inflammation at injection sites, and the burden on health care systems of providing monthly intramuscular injections.

The phase III study, called Antiretroviral Therapy as Long-Acting Suppression (ATLAS), is testing an experimental drug, cabotegravir, made by ViiV, and rilpivirine, a licensed medicine from Janssen Sciences Ireland UC in Dublin, in 618 HIV-infected people from 13 countries. All had fully suppressed the virus for at least 6 months with oral drugs. Half stayed on daily pills, while the others received an injection into the buttocks of each drug once a month. Viral suppression was the same in both groups, ViiV's statement says.

Kimberly Smith, who heads R&D for ViiV from Durham, North Carolina, says the injectables could make it easier for clinicians to know for certain that patients are adhering to their treatment. Studies have shown that about 30% of HIV-infected people have difficulty doing so at some point; even those taking just a single multidrug pill a day miss doses. Smith, an HIV/AIDS clinician before she came to ViiV, says, "I experienced having patients die … because they just couldn't get over that hurdle of taking that pill every day." Read more via Science