Monthly injections of long-acting cabotegravir (ViiV Healthcare) and rilpivirine (Edurant, Janssen) can suppress HIV as well as daily oral antiretroviral treatment, according to results from the ATLAS (NCT02951052) and FLAIR (NCT02938520) trials.
These studies are a "landmark" in the treatment of HIV, said Tom Giordano, MD, from the Baylor College of Medicine in Houston, who was not involved in either study. "They demonstrate noninferiority with a totally new paradigm of treatment."
But it is not clear what role the injections — which are not yet approved by the US Food and Drug Administration — will play in ending the epidemic.
The FLAIR and ATLAS trials — both presented at the Conference on Retroviruses and Opportunistic Infections 2019 — were designed to determine whether the combination injections could suppress HIV in people new to treatment and in those already on treatment.
There were some surprising findings. Because the studies were conducted at multiple sites in Europe, North America, and Russia, the researchers had a chance to test the treatment in people with a variety of HIV subtypes. Three participants in each trial developed treatment-resistant mutations to non-nucleoside reverse-transcriptase inhibitors (NNRTIs) and protease inhibitors. In FLAIR, the two women and one man were from Russia and had HIV subtype 1A.
This is an issue that "warrants further investigation," said Chloe Orkin, MD, from Barts Health NHS Trust in London, who presented the FLAIR data. The research team is looking at the mutagenesis of this virus but has yet to find a specific answer, she explained.
Both FLAIR and ATLAS are notable for who was left out, several people pointed out.
Although ATLAS drew praise because women made up 30% of the study cohort, only 22% of FLAIR participants were women. That's not good enough, said Annette Haberl, MD, from Frankfurt University in Germany.
In the CASTLE study of atazanavir and ritonavir, 30% of participants in both treatment groups were women, and that was more than 10 years ago (Lancet. 2008;372:646-655), she told Medscape Medical News.
"Looking at the total number of participants, it should have been feasible in the ATLAS study to enroll about 300 women," said Haberl.
In addition, 78% of ATLAS participants and 74% of FLAIR participants were white. However, recent data show that only 36% of young black men in the United States were virally suppressed between 2009 and 2014 (J Acquir Immune Defic Syndr. Published online February 13, 2019), and black trans and nontrans women consistently have lower viral suppression rates and worse outcomes than their white counterparts.
This is particularly relevant because people who are in care but not virally suppressed accounted for 19.8% of HIV transmissions in 2016, according to newly released data, as reported by Medscape Medical News.