SUAT: Switch to Unboosted Atazanavir With Tenofovir Study

• Sponsor: University of British Columbia (Other)
• Overall Status: Completed
• CT.gov ID: NCT01351740
• Collaborator: (none)
• Enrollment: 50
• Location: 1
• Arms: 2
• Duration (Months): 53
• Patients Per Site Per Month: 0.9

Study Details

Study Description

Brief 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.

Condition or Disease	Intervention/Treatment	Phase
HIV Infection	Drug: atazanavir; Drug: atazanavir/ritonavir	Phase 4

Detailed Description

Following a screening visit to establish study eligibility, eligible consenting subjects will be randomized 1:1 to one of the two treatment arms (switch to unboosted ATZ or continue ritonavir-boosted ATZ). Randomized open-label treatment will commence following study procedures at baseline. Participants will be assessed at baseline and at weeks 4, 8, 12, 24, 36, and 48. On-study evaluations will include assessment of adverse clinical events and medication changes; blood tests for HIV viral load, CD4 cell count, standard safety parameters, fasting lipids and glucose, and pregnancy testing (if applicable); and urine tests for urinalysis and albumin to creatinine ratio. In addition, a serum sample will be stored at each visit for possible future testing. A timed plasma sample for measurement of pre-dose trough ATZ levels will be obtained once per subject at 4-8 weeks. Quality of life will be assessed by completion of the MOS-HIV questionnaire at baseline and every 12 weeks. Adherence will be assessed based on prescription refill data.

In case of protocol-defined virologic failure, a plasma sample for ATZ trough level will be collected, and genotypic resistance testing will be performed on plasma samples with viral load >250 copies/mL. Subjects with confirmed virologic failure will be asked to come to the clinic and will have their HIV treatment changed to a more effective regimen, selected based on the results of genotypic testing, as soon as possible.

The anticipated rate of confirmed virologic failure in the control arm is no more than 15% over the 48 weeks of the study. Once at least 20 subjects have been assigned to the experimental (switch) treatment arm, if the observed confirmed virologic failure rate in the experimental arm is greater than twice this rate, i.e. >30%, at any time during the study, the study will be stopped. At this time, subjects in the experimental arm will be reassessed as soon as possible and will resume ritonavir-boosted atazanavir or other effective HIV therapy as appropriate. The failure rate will be reassessed at a minimum after each 20 subjects are enrolled into the experimental (switch) arm.

Study Design

• Study Type: Interventional
• Actual Enrollment: 50 participants
• Allocation: Randomized
• Intervention Model: Parallel Assignment
• Masking: None (Open Label)
• Primary Purpose: Treatment
• Official Title: Switch to Unboosted Atazanavir With Tenofovir (SUAT) Study
• Study Start Date: Jul 1, 2011
• Actual Primary Completion Date: Jan 1, 2015
• Actual Study Completion Date: Dec 1, 2015

Arms and Interventions

Arm	Intervention/Treatment
Experimental: Switch switch to unboosted atazanavir 400mg daily with the same nucleoside (NRTI) backbone	Drug: atazanavir; switch to unboosted atazanavir 400 mg daily
Active Comparator: Continuation continue on current regimen of atazanavir/ritonavir 300mg/100mg with the same nucleoside (NRTI) backbone	Drug: atazanavir/ritonavir; Continue current regimen of atazanavir 300 mg/ ritonavir 100 mg daily

Outcome Measures

Primary Outcome Measures

1. Proportions of Subjects Experiencing Virologic Failure by Randomized Treatment Arm [at or before 48 weeks.]

   For the purposes of the study, virologic failure is defined as either regimen change for any reason, or plasma viral load >400 copies/mL on 2 consecutive measurements >2 weeks apart.

Secondary Outcome Measures

1. Proportions of Subjects in Each Randomized Treatment Arm With Atazanavir Trough Levels Below 150ng/mL [1 month (4-8 weeks)]

   Therapeutic drug monitoring (TDM) to determine atazanavir trough plasma level will be performed once on all subjects at 4-8 weeks

2. Proportion of Subjects Experiencing Virologic Failure by Results of 1-month TDM [at or before 48 weeks]

   For the purposes of the study, virologic failure is defined as either regimen change for any reason, or plasma viral load >400 copies/mL on 2 consecutive measurements >2 weeks apart. Comparison will be made between subjects with 1-month (4-8 week) on-study atazanavir trough levels <150ng/mL and those with 1-month (4-8 week) on-study atazanavir trough levels >150ng/mL.

3. Proportions of Subjects Experiencing Virologic Failure by Randomized Treatment Arm [at or before 24 weeks.]

   For the purposes of the study, virologic failure is defined as either regimen change for any reason, or plasma viral load >400 copies/mL on 2 consecutive measurements >2 weeks apart.

4. Proportion of Subjects Experiencing Virologic Failure by Results of 1-month TDM [at or before 24 weeks]

   For the purposes of the study, virologic failure is defined as either regimen change for any reason, or plasma viral load >400 copies/mL on 2 consecutive measurements >2 weeks apart. Comparison will be made between subjects with 1-month (4-8 week) on-study atazanavir trough levels <150ng/mL and those with 1-month (4-8 week) on-study atazanavir trough levels >150ng/mL.

5. CD4 Cell Count Changes (Absolute and Fraction) [24 and 48 weeks]

   Comparison will be made between randomized treatment arms.

6. Safety (Clinical and Laboratory Adverse Events) [24 and 48 weeks]

   Serious adverse events and discontinuations will be compared between randomized treatment arms

7. Total Serum Bilirubin Levels [24 and 48 weeks]

   Comparison will be made between randomized treatment arms.

8. Metabolic Parameters [24 and 48 weeks]

   Comparison will be made between randomized treatment arms with respect to changes in fasting lipids and glucose, highly sensitive C-reactive protein [hsCRP], and apolipoprotein [apo]B, and proportions of subjects developing abnormalities or crossing predefined limits (e.g. NCEP thresholds for lipids)

9. Quality of Life as Assessed by MOS-HIV [24 and 48 weeks]

   Changes in MOS-HIV scores from baseline will be compared between randomized treatment arms.

Eligibility Criteria

Criteria

• Ages Eligible for Study: 19 Years and Older
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: No

Inclusion Criteria:

1. HIV infected adults at least 19 years of age

2. Willing and able to provide informed consent to study participation

3. Currently receiving a regimen including atazanavir 300mg/ritonavir 100mg daily with either tenofovir/emtricitabine (FTC) or tenofovir/lamivudine (3TC), for at least 3 months

4. Plasma viral load (VL) <40 copies/mL for at least 2 consecutive measurements including the screening value, and < 150 copies/mL continuously for at least 3 months prior to screening

5. Current regimen is first antiretroviral regimen, or if not first regimen, no evidence of resistance to any nucleosides (NRTIs) or protease inhibitors (PIs) on previous resistance tests

6. Any CD4

Exclusion Criteria:

1. Clinically significant intolerance or toxicity with current regimen precluding regimen continuation (e.g. intolerance/toxicity to ritonavir necessitating ritonavir discontinuation)

2. pregnancy or breast-feeding

3. antiretroviral regimen including any nonnucleoside reverse transcriptase inhibitor (nevirapine, efavirenz, or etravirine)

4. antiretroviral regimen including any protease inhibitor other than atazanavir and ritonavir

5. concomitant treatment with proton pump inhibitors, rifampin, St. John's wort, or garlic supplements. (Antacids and H2 receptor antagonists will be allowed provided their dosing is separated from atazanavir administration by at least 2 and 10 hours, respectively).

Contacts and Locations

Locations

	Site	City	State	Country	Postal Code
1	Immunodeficiency Clinic, St. Paul's Hospital	Vancouver	British Columbia	Canada	V6Z1Y6

Sponsors and Collaborators

• University of British Columbia

Investigators

• Principal Investigator: Marianne Harris, MD, Providence Health Care/ University of British Columbia

Study Documents (Full-Text)

None provided.

More Information

Additional Information:

• Journal article

Publications

None provided.

• Responsible Party: Marianne Harris, MD, Dr. Marianne Harris, University of British Columbia
• ClinicalTrials.gov Identifier: NCT01351740
• Other Study ID Numbers: H10-03255; H10-03255
• First Posted: May 11, 2011
• Last Update Posted: Jul 30, 2018
• Last Verified: Oct 1, 2017

• Keywords provided by Marianne Harris, MD, Dr. Marianne Harris, University of British Columbia: HIV; Anti-HIV Agents; HIV Protease Inhibitors
• Additional relevant MeSH terms: HIV Infections; Ritonavir; Atazanavir Sulfate

Study Results

Participant Flow

Arm/Group Title	Switch	Continuation
Arm/Group Description	switch to unboosted atazanavir 400mg daily with the same nucleoside (NRTI) backbone atazanavir: switch to unboosted atazanavir 400 mg daily	continue on current regimen of atazanavir/ritonavir 300mg/100mg with the same nucleoside (NRTI) backbone atazanavir/ritonavir: Continue current regimen of atazanavir 300 mg/ ritonavir 100 mg daily
Period Title: Overall Study
STARTED	25	25
COMPLETED	23	19
NOT COMPLETED	2	6

Baseline Characteristics

Arm/Group Title	Switch	Continuation	Total
Arm/Group Description	Switch to atazanavir 400 mg daily	Remain on atazanavir/ritonavir 300mg/100 mg daily	Total of all reporting groups
Overall Participants	25	25	50
Age (years) [Median (Inter-Quartile Range) ]
Median (Inter-Quartile Range) [years]	48	46	47
Sex: Female, Male (Count of Participants)
Female	2 8%	2 8%	4 8%
Male	23 92%	23 92%	46 92%

Outcome Measures

1. Primary Outcome

Title	Proportions of Subjects Experiencing Virologic Failure by Randomized Treatment Arm
Description	For the purposes of the study, virologic failure is defined as either regimen change for any reason, or plasma viral load >400 copies/mL on 2 consecutive measurements >2 weeks apart.
Time Frame	at or before 48 weeks.

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Switch	Continuation
Arm/Group Description	Switch to atazanavir 400 mg daily	Remain on atazanavir/ritonavir 300mg/100mg daily
Measure Participants	25	25
Count of Participants [Participants]	2 8%	6 24%

2. Secondary Outcome

Title	Proportions of Subjects in Each Randomized Treatment Arm With Atazanavir Trough Levels Below 150ng/mL
Description	Therapeutic drug monitoring (TDM) to determine atazanavir trough plasma level will be performed once on all subjects at 4-8 weeks
Time Frame	1 month (4-8 weeks)

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title	Switch	Continuation
Arm/Group Description	Switch to atazanavir 400 mg daily	Remain on atazanavir/ritonavir 300mg/100mg
Measure Participants	24	12
Count of Participants [Participants]	14 56%	3 12%

3. Secondary Outcome

Title	Proportion of Subjects Experiencing Virologic Failure by Results of 1-month TDM
Description	For the purposes of the study, virologic failure is defined as either regimen change for any reason, or plasma viral load >400 copies/mL on 2 consecutive measurements >2 weeks apart. Comparison will be made between subjects with 1-month (4-8 week) on-study atazanavir trough levels <150ng/mL and those with 1-month (4-8 week) on-study atazanavir trough levels >150ng/mL.
Time Frame	at or before 48 weeks

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title

Arm/Group Description

4. Secondary Outcome

Title	Proportions of Subjects Experiencing Virologic Failure by Randomized Treatment Arm
Description	For the purposes of the study, virologic failure is defined as either regimen change for any reason, or plasma viral load >400 copies/mL on 2 consecutive measurements >2 weeks apart.
Time Frame	at or before 24 weeks.

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title

Arm/Group Description

5. Secondary Outcome

Title	Proportion of Subjects Experiencing Virologic Failure by Results of 1-month TDM
Description	For the purposes of the study, virologic failure is defined as either regimen change for any reason, or plasma viral load >400 copies/mL on 2 consecutive measurements >2 weeks apart. Comparison will be made between subjects with 1-month (4-8 week) on-study atazanavir trough levels <150ng/mL and those with 1-month (4-8 week) on-study atazanavir trough levels >150ng/mL.
Time Frame	at or before 24 weeks

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title

Arm/Group Description

6. Secondary Outcome

Title	CD4 Cell Count Changes (Absolute and Fraction)
Description	Comparison will be made between randomized treatment arms.
Time Frame	24 and 48 weeks

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title

Arm/Group Description

7. Secondary Outcome

Title	Safety (Clinical and Laboratory Adverse Events)
Description	Serious adverse events and discontinuations will be compared between randomized treatment arms
Time Frame	24 and 48 weeks

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title

Arm/Group Description

8. Secondary Outcome

Title	Total Serum Bilirubin Levels
Description	Comparison will be made between randomized treatment arms.
Time Frame	24 and 48 weeks

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title

Arm/Group Description

9. Secondary Outcome

Title	Metabolic Parameters
Description	Comparison will be made between randomized treatment arms with respect to changes in fasting lipids and glucose, highly sensitive C-reactive protein [hsCRP], and apolipoprotein [apo]B, and proportions of subjects developing abnormalities or crossing predefined limits (e.g. NCEP thresholds for lipids)
Time Frame	24 and 48 weeks

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title

Arm/Group Description

10. Secondary Outcome

Title	Quality of Life as Assessed by MOS-HIV
Description	Changes in MOS-HIV scores from baseline will be compared between randomized treatment arms.
Time Frame	24 and 48 weeks

Outcome Measure Data

Analysis Population Description

[Not Specified]

Arm/Group Title

Arm/Group Description

Adverse Events

Time Frame	48 weeks
Arm/Group Title	Switch		Continuation
Arm/Group Description	Switch to atazanavir 400 mg daily		Remain on atazanavir/ritonavir 300 mg/100 mg daily
All Cause Mortality
	Switch		Continuation
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/25 (0%)		0/25 (0%)
Serious Adverse Events
	Switch		Continuation
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/25 (0%)		0/25 (0%)
Other (Not Including Serious) Adverse Events
	Switch		Continuation
	Affected / at Risk (%)	# Events	Affected / at Risk (%)	# Events
Total	0/25 (0%)		3/25 (12%)
Gastrointestinal disorders
diarrhea	0/25 (0%)		1/25 (4%)
Renal and urinary disorders
renal toxicity	0/25 (0%)		2/25 (8%)

Limitations/Caveats

[Not Specified]

More Information

Certain Agreements

All Principal Investigators ARE employed by the organization sponsoring the study.

There is NOT an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.