Clinical Trials


Microboosting of Atazanavir 300 mg With 50 mg Versus 100mg Ritonavir Daily in HIV-infected Patients: a Pharmacokinetic Study

This study has been completed
Ottawa Hospital Research Institute

Bristol-Myers Squibb

Information provided by (Responsible Party)
Ottawa Hospital Research Institute Identifier

First received: January 10, 2014
Last updated: September 21, 2015
Last Verified: September 2015
History of Changes


This is an open-label, single group study to determine the pharmacokinetic profile of atazanavir 300 mg daily boosted with ritonavir 100mg daily in HIV-infected patients over a period of 9 days.

Ritonavir and atazanavir are protease inhibitors used to treat HIV. However, ritonavir, when used at low doses (up to 100mg) does not have HIV activity, but will enhance (boost) the blood concentrations of other drugs like atazanavir.

Recently, a study showed that taking 50mg of ritonavir administered in an oral solution led to similar blood concentrations of atazanavir than when given with 100mg of ritonavir. Potential benefits associated with a lower dose of ritonavir may include a reduction of side effects such as upset stomach and an improvement in cholesterol level. This study will look at the amount of atazanavir into your blood when given with ritonavir in a tablet formulation at 50mg or 100mg with standard atazanavir dose (300mg).

Condition Intervention Phase
HIV Infection

Drug : atazanavir 300mg boosted with ritonavir 50 mg
Phase 1

Study Type: Interventional
Study Design: Allocation: N/A
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Supportive Care
Official Title: Microboosting of Atazanavir 300 mg With 50 mg Versus 100 mg Ritonavir Daily in HIV-infected Patients: a Pharmacokinetic Study

Further study details as provided by Ottawa Hospital Research Institute:

Primary Outcome Measures

  • Pharmacokinetics [ Time Frame: 9 days ]
    main pharmacokinetic parameters of atazanavir: AUC0-24h, Cmax and Cmin.
Secondary Outcome Measures:
  • adverse events [ Time Frame: 9 days ]
    the main pharmacokinetic parameters of ritonavir: AUC0-24h, Cmax and Cmin, , adverse events and preference, as reported by patients during the study period.

Enrollment: 12
Study Start Date: January 2014
Study Completion Date: September 2015
Primary Completion Date: November 2014 (Final data collection date for primary outcome measure)

Arms Assigned Interventions
Experimental: atazanavir 300mg boosted with ritonavir 100mg
Two period drug interaction. Period one: atazanavir 300mg boosted with ritonavir 100 mg once daily as part of current treatment standard of care. Period two: atazanavir 300 mg boosted with ritonavir 50 mg once daily for study days 2-8 inclusive
Drug: atazanavir 300mg boosted with ritonavir 50 mg
  • atazanavir 300 mg with ritonavir 100 mg once a day at 8:00 am for study day 1 and 9.
  • atazanavir 300 mg with ritonavir 50 mg once a day at 8:00 am for 7 consecutive days (study days 2-8)

Other Name:
  • Reyataz
  • ATV
  • Norvir
  • RTV



Ages Eligible for Study: 18 Years to 70 Years  
Sexes Eligible for Study: All  
Accepts Healthy Volunteers: No  


Inclusion Criteria:

  • Patients meeting the following criteria will be eligible for participation in this study:
    1. Signed informed consent prior to any study-related activities.
    2. Documented HIV infection.
    3. Male or female patients between 18 and 70 years of age inclusively.
    4. Medication history, vital signs and physical exam adequately showing no signs of acute illness at screening, as per the assessment by the physician.
    5. Patients must be willing to stop using any herbal or natural health products for 4 weeks prior to and during the study including:
  • Grapefruit, grapefruit juice, St. John's Wort and any others as determined by the investigators. ~#o2~ Patients must be on an antiretroviral regimen with atazanavir/ ritonavir 300/100 mg daily as the only protease inhibitor plus any combination of nucleoside reverse transcriptase inhibitors, for at least four weeks.
  • VL<40 copies/mL on the most recent measurement, during treatment with atazanavir 300 mg daily and ritonavir 100 mg daily, which must be within 12 weeks of the study start date.
  • Reproductive Status: Definition of Women of Child-Bearing Potential (WOCBP). WOCBP comprises women who have experienced menarche and who have not undergone successful surgical sterilization (hysterectomy, bilateral tubal ligation, or bilateral oophorectomy) or who are not post-menopausal (see definition below).
  • WOCBP must be using an acceptable method of contraception to avoid pregnancy throughout the study and for up to 4 weeks after the last dose of study drug in such a manner that the risk of pregnancy is minimized.
  • WOCBP must have a negative serum or urine pregnancy test result (minimum sensitivity 25 IU/L or equivalent units of HCG) within 0 to 72 hours before the first dose of study drug.
  • Women must not be breast-feeding.
  • Sexually active fertile men must use effective birth control if their partners are WOCBP

  • Exclusion Criteria:

  • Patients meeting one or more of the following criteria will be excluded from the study:
  • Female patients of childbearing potential who:
    1. Has a positive urine pregnancy test at screening.
    2. Have not been using a barrier method of contraception (such as diaphragm with spermicidal cream/jelly or condoms with spermicidal foam), for at least 3 months prior to participation in the study.
    3. Is not willing or able to use a reliable method of barrier contraception during the study.
    4. Is breastfeeding.
  • Patients with prior history of treatment failure on a PI based regimen, or with genotypic evidence of resistance associated mutations to protease inhibitors.
  • Use of any medication listed in Appendix I within 4 weeks prior to screening.
  • Use of any over-the-counter or prescription medications in the two weeks prior to Day 1 of the study that may interfere with absorption, distribution, metabolism or excretion of the study medications.
  • Inability to adhere to protocol.
  • Patients may be excluded from the study for other reasons, at the investigator's discretion.

    contacts and locations

    Contacts and Locations

    Choosing to participate in a study is an important personal decision.Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below.For general information, see Learn About Clinical Studies.

    Please refer to this study by its identifier: NCT02034838


    The Ottawa Hospital
    Ottawa, Ontario, Canada, K1H 8L6

    Sponsors and Collaborators

    Ottawa Hospital Research Institute
    Bristol-Myers Squibb


    Principal Investigator: William Cameron, MD, FRCPC The Ottawa Hospital
    More Information

    More Information

    Responsible Party: Ottawa Hospital Research Institute Identifier: NCT02034838   History of Changes  
    Other Study ID Numbers: AI424-979  
    Study First Received: January 10, 2014  
    Last Updated: September 21, 2015  

    Keywords provided by Ottawa Hospital Research Institute:


    Additional relevant MeSH terms:
    HIV Infections
    Atazanavir Sulfate processed this data on May 28, 2020
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