The Possibility of PrEP that's Not Truvada
Results from the HPTN 069/ACTG 5305 trial (aptly dubbed NEXT-PREP) are in, and they show that Maraviroc-based regimens are highly effective at preventing HIV.
A research abstract showed that among 406 men enrolled at 12 sites, five seroconversions occurred among those being given a version of Maraviroc as PrEP. Four of those were associated with low or undetectable drug levels. The results were presented at the Conference on Retroviruses and Opportunistic Infections (CROI) in Boston.
Maraviroc is an already FDA-approved HIV entry inhibitor that concentrates in the genital tract/rectum and is taken once daily, making it a possible alternative to Truvada PrEP.
The phase II trial examined the safety and tolerability of four regimens: Maraviroc alone, Maraviroc plus emtricitabine (FTC), Maraviroc plus tenofovir (TDF) and TDF plus FTC (Truvada as PrEP).
In a random test of 122 participants at random times, 93 percent had detectable study drug plasma levels. Among the five seroconversions, two subjects never had study drug present in their plasma at any visit. The three other seroconversions occurred in the branch given Maraviroc alone.
All of those who seroconverted had R5 virus (a common strain of HIV that attaches to the CCR5 co-receptor on a CD4 cell) and no genotypic resistance.
To participate in the study, participants had to be adult, HIV-negative men who reported a history of condomless anal intercourse with at least one HIV-infected or unknown-status man within 90 days. “Patients received randomized study regimens for 48 weeks with follow-up visits at weeks two, four, eight, and then every eight weeks,” according to the abstract. “At each study visit, interval history, physical exam, safety laboratories, blood plasma for drug levels, and HIV and adherence counseling and tested were conducted.”
The 406 men had a median age of 30 but ranged in age from 18 to 70. More than 60 percent of the volunteers were white, 28 percent black, 22 percent Latino, and 10 percent other races. Of the initial 406, 9 percent permanently discontinued the study regimen prior to 48 weeks and 9 percent were lost to follow-up.
The rates of grade two to four adverse events did not differ in pairwise comparisons among study arms.
“Given as HIV PrEP in MSM, MVC-based regimens were comparably safe and well-tolerated versus the control regimen of TDF+FTC,” the authors concluded.
Breaking HIV Prevention News for Women, too: Vaginal Ring Shows Success
Meanwhile, a vaginal ring that continuously releases antiretroviral medication has shown a modest level of protection against HIV in a large clinical trial in sub-Saharan African countries.
The National Institute of Allergies and Infectious Diseases announced Monday in a news release that the ring reduced the risk of HIV infection by 27 percent in the study population overall and by 61 percent among women ages 25 and older, who used the ring more consistently.
The results were announced at CROI and published simultaneously in the New England Journal of Medicine.
“Women need a discreet, long-acting form of HIV prevention that they control and want to use,” said Dr. Anthony Fauci, director of the NIAID, part of the National Institutes of Health (NIH). “Further research is needed to understand the age-related disparities in the observed level of protection.”