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A Comparison of Two Tests for Anti-HIV Drug Resistance

This study has been completed.
Information provided by:
National Institute of Allergy and Infectious Diseases (NIAID) Identifier:
First received: November 8, 2000
Last updated: September 24, 2008
Last verified: July 2004

The purpose of this study is to compare 2 different types of tests of the HIV virus to see which specific anti-HIV drugs would work the best.

Drug resistance is a major reason for therapy failure in HIV patients. Two types of tests can detect resistance to drugs: 1) genotyping (sequencing), which looks at the DNA sequence of a virus to see whether it has developed any genetic resistance; 2) phenotyping, which looks at the ability of different drugs to suppress virus growth in the laboratory. Genotyping and phenotyping can help doctors give patients the most effective drug therapy.

HIV Infections

Study Type: Observational
Official Title: HIV-1 Resistance Testing During Antiretroviral Failure: Comparison of Sequencing Versus Phenotyping

Resource links provided by NLM:

Further study details as provided by National Institute of Allergy and Infectious Diseases (NIAID):

Estimated Enrollment: 600
Detailed Description:

The emergence of drug resistance is a major factor contributing to the failure of antiretroviral therapy in HIV-infected patients. Drug resistance can be detected by genotypic or phenotypic assays, both having distinct advantages and disadvantages. Results from genotypic and phenotypic testing are helpful in excluding from the subsequent regimen drugs to which the resistance is identified, and both tests predict virologic response to salvage therapy in patients who have failed a previous regimen. Resistance testing is likely to be beneficial as an aid in selecting a salvage regimen.

At entry, patients are randomized to Arm A (sequencing) or Arm B (phenotyping) and have a resistance test drawn while still receiving the current regimen even though regimen failure is suspected. The test results are available between Weeks 1 and 4, inclusive. There are weekly visits for the first 4 weeks after entry to monitor viral load and maintenance of the current failing (prestudy) regimen. If virologic failure is confirmed, a new regimen is chosen and prescribed at the first visit after resistance test results are available. [AS PER AMENDMENT 12/6/00: If the resistance assay fails to yield results, another regimen is chosen and prescribed based on the patient's medical and medication history.] If virologic failure is not confirmed, the current drug regimen is not changed. Otherwise, on-site study visits occur every 4 weeks until Week 24 and then every 8 weeks thereafter through Week 48. [AS PER AMENDMENT 12/6/00: on-site study visits occur every 4 weeks until Week 24 and then every 8 weeks thereafter]. Medical resource use is assessed at baseline and then every 8 weeks through Week 48. Quality of life is assessed at baseline and then every 16 weeks through Week 48.


Ages Eligible for Study:   14 Years and older   (Child, Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria

Patients may be eligible for this study if they:

  • Are HIV-positive.
  • Have failed 2 to 4 anti-HIV regimens containing 3 or more combinations of drugs. A patient has failed his/her current regimen if he/she has, within 30 days of study entry, either a viral load (level of HIV in the blood) of at least 10,000 copies/ml or 2 tests which show a viral load between 1,000 and 10,000 copies/ml.
  • Have taken 3 or more anti-HIV drugs for 8 or more weeks before the study.
  • Are at least 14 years old.
  • Have consent of parent or guardian if less than 18 years old.

Exclusion Criteria

Patients will not be eligible for this study if they:

  • Have failed only 1 anti-HIV drug combination.
  • Have failed 5 or more anti-HIV drug combinations, each containing 3 to 5 drugs.
  • Have had and received the results of prior resistance tests.
  • Have had treatment with a combination of 6 or more anti-HIV drugs.
  • Have problems absorbing food in the intestine.
  • Have had HIV vaccines.
  • Have taken drugs that affect the immune system or investigational drugs.
  • Are taking medications not allowed with protease inhibitors (PIs) if PIs would be part of their anti-HIV treatment during the study.
  • Have failed anti-HIV therapy due to nonadherence to medication.
  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: NCT00006490

  Show 47 Study Locations
Sponsors and Collaborators
National Institute of Allergy and Infectious Diseases (NIAID)
Study Chair: Richard D'Aquila
Study Chair: Daniel Kuritzkes
  More Information Identifier: NCT00006490     History of Changes
Other Study ID Numbers: ACTG A5076
Study First Received: November 8, 2000
Last Updated: September 24, 2008

Keywords provided by National Institute of Allergy and Infectious Diseases (NIAID):
Drug Resistance, Microbial
Sequence Analysis, DNA
Microbial Sensitivity Tests
Anti-HIV Agents

Additional relevant MeSH terms:
HIV Infections
Lentivirus Infections
Retroviridae Infections
RNA Virus Infections
Virus Diseases
Sexually Transmitted Diseases, Viral
Sexually Transmitted Diseases
Immunologic Deficiency Syndromes
Immune System Diseases processed this record on September 25, 2017