An Evaluation of the Development of Nevirapine Induced Mutations in HIV Patients Initiating or Discontinuing Combination Antiretroviral Therapy

This study has been terminated.
Sponsor:
Information provided by:
University Health Network, Toronto
ClinicalTrials.gov Identifier:
NCT00193947
First received: September 15, 2005
Last updated: August 2, 2011
Last verified: April 2007
  Purpose

Hypothesis

Nevirapine resistance developed in women and infants in the HIVNET 006 and 012 cohorts as a consequence of use of an agent with a long t½ as monotherapy in individuals with high viral loads.

Objective 1 To demonstrate that Nevirapine resistance does not develop in HIV infected patients when used as part of triple antiretroviral combination therapy between the initiation of treatment and suppression of HIV RNA to <1000 copies/ml.

Objective 2 To demonstrate that resistance to nevirapine does not develop when patients with suppressed HIV RNA discontinue combination antiretroviral therapy which contains nevirapine.


Condition Phase
Drug Resistance
Phase 4

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective
Official Title: An Evaluation of the Development of Nevirapine Induced Mutations in HIV Patients Initiating or Discontinuing Combination Antiretroviral Therapy

Resource links provided by NLM:


Further study details as provided by University Health Network, Toronto:

Primary Outcome Measures:
  • To demonstrate that Nevirapine resistance does not develop in HIV infected patients when used as part of triple antiretroviral combination therapy between the initiation of treatment and suppression of HIV RNA to <1000 copies/ml. [ Time Frame: during viral suppression ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • to determine whether ARV resistance emerges when pregnant women discontinue ARV [ Time Frame: 6 months after drug discontinutation or until viral rebound ] [ Designated as safety issue: No ]

Estimated Enrollment: 56
Study Start Date: November 2003
Study Completion Date: May 2008
Groups/Cohorts
women initiating ARV therapy during pregnancy with neveripine

  Hide Detailed Description

Detailed Description:

The HIVNET 012 clinical trial demonstrates a cost effective strategy to prevent maternal fetal transmission of HIV. In this study, a single 200 mg dose of Nevirapine was given to pregnant Ugandan women at the onset of labour and a single 2 mg/kg dose to their infants within 72 hours of birth (1). Given the efficacy, simplicity and low cost of this regime, the World Health Organization recently recommended implementation of this regimen as one of several options for prevention of maternal fetal transmission of HIV in resource limited settings.

Pharmacokinetic studies have demonstrated that 200 mg of Nevirapine given to the mother during labour results in concentrations >100 mg/mL (10 times the in vitro IC50) in the newborn. Nevirapine elimination is prolonged in both mothers and infants with median t½ of 36.8 to 65.7 hours. Administration of 200 mg orally to the mother and a single 2 mg/kg oral dose to the infant at 48-72 hours, maintains serum concentration in the infants >100 mg/ml through 7 days of life (2, 3)

Early studies demonstrated that the use of Nevirapine monotherapy resulted in a rapid selection of Nevirapine resistant mutations (4). This was associated with loss of antiviral activity and return of the viral load to baseline within 12 weeks. It appeared very soon that the non-nucleoside reverse transcriptase inhibitors were drugs with a low genetic barrier and that a single mutation in the reverse transcriptase gene induced a high level of phenotypic resistance (5). Similarly, when Nevirapine was used in combination with a single nucleoside, and there was incomplete suppression of viral replication, resistance emerged to the non-nucleoside reverse transcriptase inhibitor (6).

In contrast, when used as part of triple antiretroviral combination and there was successful inhibition of viral replication to <50 copies/ml, the viral response was maintained in 50% of patients out to 48 weeks (7, 8, 9, 10). However, again when virologic control is lost, resistance to Nevirapine emerges rapidly in 50-100% of patients (11). It is unclear whether or not these mutations developed during the initial suppression of viral load replication or during rebound of viremia with failure.

Given the pharmacokinetics of Nevirapine in pregnant women and infants, concern was raised that mother and child would be exposed to Nevirapine monotherapy for one to several days and that the selection of resistant mutants could arise limiting this strategy over the long term. In fact, a recent sub-analysis of the HIVNET 012 cohort found Nevirapine resistant mutations in 21/111 (19%) of women tested at 6-8 weeks after delivery. The K103N was the most common mutation. Women with the highest baseline viral load developed the mutations more frequently. Nevirapine resistant mutations were also detected in 11/24 or (46%) of infected infants at 6-8 weeks. In contrast to the mothers, the Y181C was the most commonly detected.

Similarly, the K103N resistance mutation was detected 6 weeks after Nevirapine administration in 3/15 (20%) women in the HIVNET006 phase I/II trial. This had the same Nevirapine dosing schedule as HIVNET012 (12).

New information has become available based on recent post-marketing surveillance data clarifying risk factors for severe life threatening and fatal hepatotoxicity with nevirapine. Women with CD4 counts > 250 cellsmm3 at initiation of therapy including pregnant women receiving chronic treatment for HIV infection are at considerably higher risk (12-fold) of hepatotoxicity which in some cases has been fatal. The greatest risk of severe and potentially fatal hepatic events occurs in the first 6 weeks of therapy. However, the risk continues after this time and patients should be closely monitored for the first 18 weeks of therapy. For this reason, women with CD4 > 250/mm3 will not be included in Objective 1 of this study.

Hypothesis

Nevirapine resistance developed in women and infants in the HIVNET 006 and 012 cohorts as a consequence of use of an agent with a long t½ as monotherapy in individuals with high viral loads.

Objective 1 To demonstrate that Nevirapine resistance does not develop in HIV infected patients when used as part of triple antiretroviral combination therapy between the initiation of treatment and suppression of HIV RNA to <1000 copies/ml.

Objective 2 To demonstrate that resistance to nevirapine does not develop when patients with suppressed HIV RNA discontinue combination antiretroviral therapy which contains nevirapine.

  Eligibility

Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Female
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population

Women attending the UHN immunodeficiency clinic

Criteria

Inclusion Criteria:Inclusion Criteria (Objective 1)

  1. HIV infected adults
  2. Antiretroviral naïve
  3. Viral load >1000 copies/ml
  4. Initiating combination antiretroviral therapy, which includes nevirapine.

Exclusion Criteria (Objective 1)

1. Women with CD4 counts > 250/mm3

Inclusion Criteria (Objective 2)

  1. HIV infected adults
  2. On their initial ARV combination which contains nevirapine
  3. HIV RNA < 50 copies/ml
  4. Decision to discontinue ARV therapy at the completion of pregnancy or for a drug holiday
  5. Not resistant to nevirapine.

Note that since most patients meeting the criteria for Objective 1 are expected to achieve HIV RNA < 50 copies/mL, the patient populations for Objectives 1 and 2 will be almost the same.

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Exclusion Criteria:

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  Contacts and Locations
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Please refer to this study by its ClinicalTrials.gov identifier: NCT00193947

Locations
Canada, Ontario
University Health Network
Toronto, Ontario, Canada, M5G 2C4
Sponsors and Collaborators
University Health Network, Toronto
Investigators
Principal Investigator: Sharon Walsmley University Health Network, Toronto
  More Information

No publications provided

Responsible Party: University Health Network Toronto, university health network
ClinicalTrials.gov Identifier: NCT00193947     History of Changes
Other Study ID Numbers: 03-0162-B
Study First Received: September 15, 2005
Last Updated: August 2, 2011
Health Authority: Canada: Health Canada

ClinicalTrials.gov processed this record on September 22, 2014