This Week in HIV Research: Maintenance Therapy Regimen Containing Lamivudine May Be Viable Option

This week, a study finds that a treatment regimen containing lamivudine (3TC, Epivir) may work as maintenance therapy for those already virally suppressed. Another study finds that vaginal bacteria may deplete the tenofovir (Viread) in a vaginal ring for HIV prevention, making the ring less effective. And the World Health Organization released its first global hepatitis report, calling for better data and more testing and treatment. To beat HIV, you have to follow the science!

Dual Maintenance Therapy With Lamivudine Viable Option

A boosted protease inhibitor (PI) combined with lamivudine is a viable maintenance therapy for those who are already virally suppressed, a clinical trial published in The Lancet HIV found.

The trial compared the boosted PI-lamivudine combination to boosted PI monotherapy in 265 people who had undetectable viral loads. Most participants were women, and almost all had the M184V mutation, which confers resistance to lamivudine and is common in Africa.

The monotherapy arm was discontinued after 48 weeks because 33 of the 133 people in this arm experienced treatment failure, compared to four of the 132 people in the lamivudine group. Given the lack of regular viral load monitoring in many low-income settings, study authors do not recommend monotherapy as a low-cost maintenance strategy.

"[D]ual therapy with boosted protease inhibitor and lamivudine in stable HIV-1-infected patients on second-line [antiretroviral treatment] could be considered as an alternative to triple therapy for selected patients, even despite the presence of M184V mutation at first-line failure," the study authors concluded.

Some Vaginal Bacteria Rapidly Deplete Tenofovir

Tenofovir in an experimental vaginal ring for HIV prevention is rapidly depleted by certain vaginal bacteria, rendering this HIV prevention method less effective, a study published in Science showed.

The vaginal biomes of 688 women who are participating in the CAPRISA 004 trial in South Africa were profiled. In almost 60% of participants bacteria were dominated by Lactobacillus, and in the remainder by Gardnerella vaginalis. The latter group showed lower rates of tenofovir in the mucosa. In vitro experiments found that G. vaginalis metabolized tenofovir faster than the body can replenish the active form of the drug.

Efficacy of the ring was consistently higher among women in the Lactobacillus group compared to the G. vaginalis group, independent of participants' level of adherence to the study regimen. The two groups of bacteria are generally associated with different pH levels in the vagina. Study authors therefore suggest that measuring vaginal acidity may be a practical way to guide decisions on using tenofovir-based topical HIV prevention methods.

World Health Organization Issues First Global Hepatitis Report

In its Global Hepatitis Report, the World Health Organization (WHO) calls for better data, more widespread testing and treatment available to everyone, money for universal health coverage, and innovations in the prevention and treatment of viral hepatitis. One notable estimate was that among people living with HIV, more than a tenth are likely coinfected with hepatitis B (HBV) or hepatitis C (HCV), but many do not know it.

The report provides 2015 estimates of the impact of viral hepatitis as a baseline for tracking progress toward the Global Health Sector Strategy goals for those diseases: 90% fewer new infections and 65% lower mortality rate by 2030. In 2015, HBV and HCV accounted for most of the 1.34 million hepatitis-related deaths. Widespread vaccination of children against HBV has helped to reduce hepatitis prevalence in that group to 1.3%. However, harm reduction services to prevent HCV acquisition from injection drug use are inadequate, and about 5% of medical injections around the world are still unsafe, WHO said.

"We have the knowledge, what we need now is action," concluded Raquel Peck of the World Hepatitis Alliance in a related press release.