One third of people with HIV in US study are not virally suppressed on antiretroviral therapy

A third of people with HIV on antiretroviral therapy (ART) do not have sustained viral suppression and many are not receiving regimens recommended by the latest U.S. treatment guidelines, according to data from the Medical Monitoring Project presented at IDWeek 2015 this month in San Diego. However, this study included many people with long-term HIV infection who may not have been able to use preferred first-line regimens.

Yunfeng Tie from ICF International and colleagues with the U.S. Centers for Disease Control and Prevention analysed data from more than 18,000 participants in the Medical Monitoring Project – an on-going national surveillance system for adults receiving HIV medical care in the U.S. – from 2009 through 2012.

Of the 18,095 total participants in the study, about three-quarters were men, 41% were black, 43% were over age 50 and the same proportion had been on ART for at least 10 years; only 5% had started ART during the past year. Although more than 70% had ever had an AIDS diagnosis, nearly half had a CD4 T-cell count above 500 cells/mm³ in the past year. About half had a high school education or less and 46% had an income at or below the poverty level. Just over 40% were smokers, 4% reported injection drug use and 25% reported non-injection drug use.

The results showed that 92% of HIV-positive adults receiving medical care were prescribed ART. Of these 52% were prescribed regimens recommended by the 2014 DHHS treatment guidelines for first-line therapy.

The most common regimen was efavirenz plus tenofovir/emtricitabine (the drugs in Atripla), taken by 27% – or about half of those prescribed a recommended first-line regimen. The next most common combos were ritonavir-boosted atazanavir (Reyataz), boosted darunavir (Prezista) and raltegravir (Isentress), all with tenofovir/emtricitabine, at 11%, 5% and 4%, respectively.

80% of participants on ART achieved undetectable viral load (HIV RNA < 200 copies/ml) after starting therapy. However, the proportion of participants who maintained durable viral suppression over the course of a year fell to 66%. More than 80% of participants reported good adherence during the past three days and 16% reported side-effects more than half the time during the prior month.

Efavirenz-based regimens were associated with the highest recent and durable viral suppression rates, as well as the best adherence. Participants prescribed recommended regimens were more likely to achieve viral suppression than those taking non-recommended regimens.

Raltegravir was associated with the fewest side-effects. People prescribed non-recommended regimens were more likely to report side-effects.

These response rates are lower than the rates generally seen in clinical trials of new antiretroviral agents – typically around 90% – but they are more in line with those observed in various 'cascade of care' studies which look at real-world clinical outcomes.

This study should be interpreted cautiously as many of the participants had extensive treatment experience and probably had drug-resistant HIV. Such people are more challenging to treat and recommended first-line regimens may not be appropriate for these patients.

Just as some of the non-recommended regimens in 2014 were recommended in earlier versions of the guidelines, the top option in this study is no longer considered the best available. As of the April 2015 guidelines update efavirenz has been taken off the recommended list, largely due to its side-effects, and replaced with well-tolerated integrase inhibitors.