Study of Pharmacokinetics in HIV-infected Women

July 27, 2012 updated by: Women's College Hospital

Predictors of Antiretroviral Pharmacokinetics in HIV-infected Women With Virologic Suppression on Combination Antiretroviral Therapy

Women represent an increasing proportion of HIV cases globally and in Canada, yet are underrepresented in clinic trials. It is therefore critical to conduct this study on antiretroviral (ARV) pharmacokinetics (PK) in women to obtain additional information on ARV drug levels in women and their relation to adverse events (AEs).

The hypothesis for this study is three-fold:

  1. that the mean drug levels (Cmin and Cmax) of ARVs will be significantly higher in our female population as compared to the mean drug levels in the historical HIV population (which is primarily men)
  2. that ARV drug levels, particularly Cmin, are associated with body weight in women
  3. that higher ARV drug levels, particularly Cmax, are associated with higher frequency and severity of AEs.

The objectives of this study are as follows:

Primary objectives:

  1. To demonstrate that levels of Protease Inhibitors (PIs) and Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs) are significantly higher in our female population as compared to the mean drug levels in the historical general population (which is primarily men).
  2. To determine the association between PI and NNRTI minimum concentration (Cmin) and body weight in our female population.

Secondary objectives

  1. To determine the association between maximum concentration (Cmax) and the frequency and severity of AEs as measured by the proportion of patients with grade 2 or higher laboratory or clinical AEs and the Symptom Index Score in women.
  2. To determine the association between ARV drug levels and age, race, height, body mass index, adherence, hormonal levels and therapy, menstruation history, duration of HIV infection, duration on ARV therapy, baseline viral load, baseline CD4 count, present CD4 count, hepatitis B or C infection, class of ARVs, presence of ritonavir and other medications.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Predictors of antiretroviral pharmacokinetics in HIV-infected women with virologic suppression on combination antiretroviral therapy

Background

Women in Canada constitute the fastest growing population groups at risk for infection with HIV and AIDS. Women now represent approximately 40% of all AIDS cases worldwide and approximately 20% of cases in Canada. Although the AIDS epidemic has been ongoing for more than 20 years, surprisingly little is known about the differential efficacy and toxicity of various antiretroviral (ARV) drugs in women as compared to men. This gap in knowledge is a result of the initial exclusion of and continued underrepresentation of women in ARV clinical trials. Many studies suggest that HIV-infected women taking ARV treatment (ART) have more adverse events (AEs) than men, especially in relationship to systemic symptoms like diarrhea, as well as organ toxicity, including hepatotoxicity, lactic acidosis, peripheral neuropathy and, notably, lipodystrophy. Currently, the occurrence and management of AEs is the most important issue in the treatment of HIV. Understanding the reasons for the differences of AEs in HIV-infected women is critical and has yet to be evaluated within a large cohort. It is unknown whether these differences relate to hormonal influences, drug metabolism, adherence, fat distribution, body size or other factors. Some small studies have found that drug levels (e.g. Cmin, Cmax, AUC) are higher in women and are associated with increased toxicity. Ultimately, we plan to conduct a randomized clinical trial (RCT) to assess the utility of therapeutic drug monitoring (TDM) and ARV drug dose adjustment on the frequency of AEs in women. Prior to conducting this RCT, it is critical to conduct this study on ARV pharmacokinetics (PK) in women to obtain additional information on ARV drug levels in women and their relation to AEs.

Hypothesis

The hypothesis for this study is three-fold:

  1. that the mean drug levels (Cmin and Cmax) of ARVs will be significantly higher in our female population as compared to the mean drug levels in the historical HIV population (which is primarily men)
  2. that ARV drug levels, particularly Cmin, are associated with body weight in women
  3. that higher ARV drug levels, particularly Cmax, are associated with higher frequency and severity of AEs.

Patient population

Eighty HIV-infected women from 8 Canadian sites who have been on their first combination ART regimen containing either a PI or an NNRTI (since these are the ARV agents eligible for PK analysis) for at least three months and who have evidence of full virologic suppression (HIV RNA VL less than 50 copies/mL) on at least two occasions at least one month apart.

Objectives Primary objectives

  1. To demonstrate that the Cmin and Cmax of PIs and NNRTIs are significantly higher in our female population as compared to the mean drug levels in the historical general population (which is primarily men).
  2. To determine the association between PI and NNRTI Cmin and body weight in our female population.

Secondary objectives

  1. To determine the association between Cmax and the frequency and severity of AEs as measured by the proportion of patients with grade 2 or higher laboratory or clinical AEs and the Symptom index score in women.
  2. To determine the association between ARV drug levels and age, race, height, body mass index, adherence, hormonal levels and therapy, menstruation history, duration of HIV infection, duration on ARV therapy, baseline VL, baseline CD4 count, present CD4 count, hepatitis B or C infection, class of ARVs, presence of ritonavir and other medications.

Study design

The study will be a cross-sectional study with ARV drug levels (Cmin and Cmax) measured weekly for three weeks Three samples will be taken from each subject to reduce variability due to both technologic and biologic sources. Data will be collected on demographic characteristics, clinical disease and ARV history and on clinical toxicities at the first visit. Blood work will be carried out on the first visit to assess for laboratory toxicity and hormonal levels.

Data analysis

Drug levels will be summarized with the mean of the 3 values for Cmin and Cmax for each woman for their PI or NNRTI and compared to the mean values of the general HIV population. Cmin and Cmax will be classified into high and low levels with a high level defined as less than or equal to 1.5 X arithmetic population mean for each drug. Characteristics of patients with high drug levels will be compared to those of patients with low drug levels. Univariate and multivariate logistic regression models will be used to identify independent associations of patient characteristics with high drug levels. The proportions of patients with AEs and the median number of AEs per patient will be compared between patients with high Cmax and patients with low Cmax.

Study Type

Observational

Enrollment (Actual)

88

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

      • Quebec, Canada, G1V 4G2
        • Chuq/Chul
    • British Columbia
      • Vancouver, British Columbia, Canada, V6Z 1Y6
        • St. Paul's Hospital
      • Vancouver, British Columbia, Canada, V6H 3N1
        • Children and Women's Hospital
      • Vancouver, British Columbia, Canada, V6Z 2C7
        • Downtown Infectious Diseases Clinic
    • Nova Scotia
      • Halifax, Nova Scotia, Canada, B3H 1V7
        • Capital District Health Authority
    • Ontario
      • Hamilton, Ontario, Canada, L8N 3Z5
        • Hamilton Health Sciences - McMaster University
      • Ottawa, Ontario, Canada, K1N 6N5
        • University of Ottawa Health Services
      • Ottawa, Ontario, Canada, K1Y 4E9
        • Ottawa Health Research Institute
      • Toronto, Ontario, Canada, M4N 3M5
        • Sunnybrook Health Sciences Centre
      • Toronto, Ontario, Canada, M5B 1W8
        • St. Michael's Hospital
      • Toronto, Ontario, Canada, M5B 1L6
        • Canadian Immunodeficiency Research Collaborative
      • Toronto, Ontario, Canada, M5G 2N2
        • University Health Network - Toronto General Hospital
      • Windsor, Ontario, Canada, N8W 1E3
        • Windsor Regional Hospital HIV Care Program
    • Quebec
      • Montreal, Quebec, Canada, H2W 1T7
        • Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CHUM)
      • Montreal, Quebec, Canada, H2X 2P4
        • Montreal Chest Institute

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 65 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Female

Sampling Method

Non-Probability Sample

Study Population

The patient population will consist of 80 HIV-infected women (who are on their first cART regimen containing either a PI or an NNRTI for at least three months and who have evidence of full virologic suppression (HIV RNA VL < 50 copies/mL) on at least two occasions at least one month apart. The first cART regimen can include ARV switches as long as these switches are not due to virologic failure. The patient population is being limited to women who have full virologic suppression to avoid inclusion of women with difficulty with drug adherence.

Description

Inclusion Criteria:

  • Patient must be HIV infected
  • Patient must be 18 years old or older
  • Patient must be a biologic woman
  • Patient must be taking her first combination ARV regimen that includes a PI or an NNRTI for the past three months with no changes in any agent of the combination in that period (first combination ARV regimen is defined as a regimen started when the patient was ARV-naïve; however switches are allowed as long as the switches are not for virologic failure)
  • Patient must be taking either a PI or an NNRTI but not both
  • If taking a PI, patient must be taking only one PI excluding low dose ritonavir used as boosting
  • Patient must have a viral load < 50 copies/mL on two occasions at least 1 month apart including a value within three months before the baseline visit
  • Patient has to have signed and dated a full informed consent

Exclusion Criteria:

  • Patient who would have difficulty participating in a trial due to non-adherence or substance abuse
  • Patient who is pregnant or breast-feeding
  • Patient with a malignancy receiving systemic chemotherapy
  • Patient with end stage organ disease
  • Patient with other significant non-HIV underlying disease that might impinge upon disease progression or death
  • Patient who is not taking standard dosing of a PI or NNRTI as listed in Appendix G

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Time Perspectives: Prospective

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Mona R Loutfy, MD FRCPC MPH, Women's College Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

February 1, 2007

Primary Completion (Actual)

February 1, 2009

Study Completion (Actual)

February 1, 2009

Study Registration Dates

First Submitted

February 9, 2007

First Submitted That Met QC Criteria

February 9, 2007

First Posted (Estimate)

February 12, 2007

Study Record Updates

Last Update Posted (Estimate)

July 30, 2012

Last Update Submitted That Met QC Criteria

July 27, 2012

Last Verified

July 1, 2012

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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