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Switch to Unboosted Atazanavir With Tenofovir Study

NCT01351740 · Status: COMPLETED · Phase: PHASE4 · Type: INTERVENTIONAL · Enrollment: 50

Last updated 2018-07-30

Study results available
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Summary

A drug-drug interaction between the anti-HIV drugs tenofovir DF (TDF) and atazanavir (ATZ) results in lower ATZ plasma levels when the drugs are given together, particularly in patients not taking ritonavir to boost ATZ levels. Lower plasma drug levels may make the anti-HIV regimen less effective in controlling the HIV virus levels in the blood. For this reason, current treatment guidelines recommend that ATZ always be boosted with ritonavir in regimens also containing TDF. However, withdrawal of ritonavir is often desirable given the tolerability and toxicity issues with this agent, even at the low dose (100 mg daily) used to boost ATZ. For example, ritonavir can cause stomach upset, nausea, diarrhea, high cholesterol levels, and liver enzyme abnormalities.

However, there is evidence that plasma ATZ levels may not predict treatment success on unboosted ATZ regimens, particularly among people whose plasma HIV virus is already under control and unboosted ATZ is being used as a maintenance strategy. In the BC Centre for Excellence in HIV/AIDS Drug Treatment Program (DTP), nearly 100 patients originally treated with ritonavir-boosted ATZ + TDF (+ FTC or 3TC) are receiving successful maintenance therapy with unboosted ATZ and the same TDF-based backbone.

The study will examine the hypothesis that switching to maintenance therapy with unboosted ATZ 400mg daily will have similar 48-week virologic efficacy to continuing ATZ/ritonavir 300/100mg daily among HIV-infected adults with stable viral load suppression on regimens comprising ATZ/ritonavir 300/100mg daily with TDF plus either FTC or 3TC, despite potentially lower ATZ trough levels with the unboosted regimen. In other words, patients whose HIV viral load is undetectable while receiving TDF (+FTC or 3TC) and ATZ/ritonavir will continue to maintain an undetectable viral load after switching to unboosted ATZ without ritonavir, in the same proportions as those continuing on their boosted ATZ/ritonavir regimen.

Conditions

  • HIV Infection

Interventions

DRUG

atazanavir

switch to unboosted atazanavir 400 mg daily

DRUG

atazanavir/ritonavir

Continue current regimen of atazanavir 300 mg/ ritonavir 100 mg daily

Sponsors & Collaborators

  • University of British Columbia

    lead OTHER

Principal Investigators

  • Marianne Harris, MD · Providence Health Care/ University of British Columbia

Study Design

Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Model
PARALLEL

Eligibility

Min Age
19 Years
Sex
ALL
Healthy Volunteers
No

Timeline & Regulatory

Start
2011-07-31
Primary Completion
2015-01-31
Completion
2015-12-31

Countries

  • Canada

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT01351740 on ClinicalTrials.gov