Thomas Campbell and colleagues report findings of a randomized trial conducted in
multiple countries regarding the efficacy of antiretroviral regimens with
simplified dosing.
Background
Antiretroviral regimens with simplified dosing and better safety are needed
to maximize the efficiency of antiretroviral delivery in resource-limited
settings. We investigated the efficacy and safety of antiretroviral regimens
with once-daily compared to twice-daily dosing in diverse areas of the
world.
Methods and Findings
1,571 HIV-1-infected persons (47% women) from nine countries in four
continents were assigned with equal probability to open-label antiretroviral
therapy with efavirenz plus lamivudine-zidovudine (EFV+3TC-ZDV), atazanavir
plus didanosine-EC plus emtricitabine (ATV+DDI+FTC), or efavirenz plus
emtricitabine-tenofovir-disoproxil fumarate (DF) (EFV+FTC-TDF). ATV+DDI+FTC
and EFV+FTC-TDF were hypothesized to be non-inferior to EFV+3TC-ZDV if the
upper one-sided 95% confidence bound for the hazard ratio (HR) was ≤1.35
when 30% of participants had treatment failure.
An independent monitoring board recommended stopping study follow-up prior to
accumulation of 472 treatment failures. Comparing EFV+FTC-TDF to
EFV+3TC-ZDV, during a median 184 wk of follow-up there were 95 treatment
failures (18%) among 526 participants versus 98 failures among 519
participants (19%; HR 0.95, 95% CI 0.72–1.27; p = 0.74).
Safety endpoints occurred in 243 (46%) participants assigned to EFV+FTC-TDF
versus 313 (60%) assigned to EFV+3TC-ZDV (HR 0.64, CI 0.54–0.76;
p<0.001) and there was a significant interaction
between sex and regimen safety (HR 0.50, CI 0.39–0.64 for women; HR 0.79, CI
0.62–1.00 for men; p = 0.01). Comparing ATV+DDI+FTC to
EFV+3TC-ZDV, during a median follow-up of 81 wk there were 108 failures
(21%) among 526 participants assigned to ATV+DDI+FTC and 76 (15%) among 519
participants assigned to EFV+3TC-ZDV (HR 1.51, CI 1.12–2.04;
p = 0.007).
Conclusion
EFV+FTC-TDF had similar high efficacy compared to EFV+3TC-ZDV in this trial
population, recruited in diverse multinational settings. Superior safety,
especially in HIV-1-infected women, and once-daily dosing of EFV+FTC-TDF are
advantageous for use of this regimen for initial treatment of HIV-1
infection in resource-limited countries. ATV+DDI+FTC had inferior efficacy
and is not recommended as an initial antiretroviral regimen.
Trial Registration
www.ClinicalTrials.gov
NCT00084136
Please see later in the article for the Editors' Summary.
Editors' Summary
Background
Despite the enormous gains in reducing HIV-related illness and death over the
past decade, there are still considerable challenges to meeting the global
goal of universal access to highly active antiretroviral treatment—a
combination of effective drugs that attack the HIV virus in various ways—to
everyone living with HIV/AIDS who could benefit from treatment. In
recognition of the related financial, technical, and system obstacles to
providing universal access to HIV treatment, in 2010 the UN agency
responsible for HIV/AIDS—UNAIDS—launched an ambitious plan called Treatment
2.0, which aims to simplify the way HIV treatment is currently provided. One
of the main focuses of Treatment 2.0 is to simplify drug regimes for the
treatment of HIV and to make treatment regimes less toxic. In line with
Treatment 2.0, the World Health Organization currently recommends that
antiretroviral regimens for the initial treatment of HIV should include two
nucleoside reverse transcriptase inhibitors (zidovudine or tenofovir
disoproxil fumarate [DF] with lamivudine or emtricitabine) and a
non-nucleoside reverse transcriptase inhibitor (efavirenz or
nevirapine.)
Why Was This Study Done?
Most of the evidence about the safety and effectiveness of clinical trials
come from clinical trials in high-income countries and thus is not generally
representative of the majority of people with HIV. So in this study, the
researchers conducted a randomized controlled trial in diverse populations
in many different settings to investigate whether antiretroviral regimens
administered once daily were as effective as twice-daily regimens and also
whether a regimen containing the drug atazanavir administered once daily was
as safe and effective as a regimen containing efavirenz—data from previous
studies have suggested that atazanavir has characteristics, such as its side
effect profile, which may make it more suitable for low income settings.
What Did the Researchers Do and Find?
The researchers recruited eligible patients from centers in Brazil, Haiti,
India, Malawi, Peru, South Africa, Thailand, the United States, and
Zimbabwe—almost half (47%) were women. Then the researchers randomly
assigned participants to one of three regimens: efavirenz 600 mg daily plus
co-formulated lamivudine-zidovudine 150 mg/300 mg twice daily (EFV+3TC-ZDV);
or atazanavir 400 mg once daily, plus didanosine-EC 400 mg once daily, plus
emtricitabine 200 mg once daily (ATV+DDI+FTC); or efavirenz 600 mg once
daily plus coformulated emtricitabine-tenofovir-DF 200 mg/300 mg once daily
(EFV+FTC-TDF). During the study period ATV+DDI+FTC was found to be inferior
to EFV+3TC-ZDV, so the Multinational Data Safety Monitoring Board ordered
this arm of the trial to stop. Then a year later, due to the low number of
treatment failures (deaths, severe HIV disease, or serious opportunistic
infections) in the remaining two arms, the board advised the trial to stop
early. So the researchers analyzed the data obtained up to this point and
pooled the results from all of the centers.
The researchers found that during an average of 184 weeks of follow-up, there
were 95 treatment failures (18%) among 526 participants taking EFV+FTC-TDF
compared to 98 failures among 519 participants taking EFV+3TC-ZDV. During an
average 81 weeks follow-up, there were 108 failures (21%) among 526
participants assigned to ATV+DDI+FTC and 76 (15%) among 519 participants
assigned to EFV+3TC-ZDV. As for safety, 243 (46%) participants assigned to
EFV+FTC-TDF reached a safety endpoint (grade 3 disease, abnormal lab
measurement, or the need to change drug) compared to 313 (60%) in the
EFV+3TC-ZDV group. Importantly, the researchers found that there was greater
risk of safety events for women assigned to EFV+3TC-ZDV and also that the
atazanavir-based regimen had a higher relative efficacy in women compared to
men.
What Do These Findings Mean?
These findings suggest that in diverse populations, EFV+FTC-TDF is as
effective as EFV+3TC-ZDV but importantly, the once-daily dosing of
EFV+FTC-TDF makes this regimen useful for the initial treatment of HIV,
especially in low-income countries. Therefore, as per the guidance in
Treatment 2.0, EFV+FTC-TDF in a single combination tablet that can be taken
once a day is an attractive option. These findings also indicate that as
ATV+DDI+FTC was found to be inferior to the other regimens, this combination
should not be used in the initial treatment of HIV. These findings also add
to the evidence that antiretroviral efficacy and safety can differ between
women and men and support further development of sex-specific
recommendations for antiretroviral regimen options.
Additional Information
Please access these Web sites via the online version of this summary at
http://dx.doi.org/10.1371/journal.pmed.1001290.
The UNAIDS website has more information about Treatment 2.0; and the WHO website provides
technical information
For an introduction to the treatment of HIV/AIDS see http://www.avert.org/treatment.htm; the AVERT site
also has personal
stories from women living with HIV/AIDS
AIDSmap provides information for individuals and communities
affected by HIV/AIDS
The ACTG website provides information about research to improve treatment of HIV and related
complications