Defining treatment failure in resource-rich settings

Area of Science:

• Virology
• Immunology
• Pharmacology

Background:

• Antiretroviral therapy (ART) aims for complete viral suppression in HIV patients.
• Defining treatment failure is crucial for optimizing ART efficacy in resource-rich settings.

Purpose of the Study:

• To define treatment failure in resource-rich settings.
• To summarize current guidelines, assays, and the significance of detectable viremia.
• To clarify definitions of treatment failure in clinical and research contexts.

Main Methods:

• Review of current guidelines and clinical trial data.
• Analysis of various HIV RNA assays and their lower limits of detection.
• Evaluation of definitions for treatment failure based on viral load thresholds.

Main Results:

• The primary goal of ART is complete viral suppression, even in treatment-experienced individuals.
• Repeated HIV RNA levels above the assay's lower limit of detection (typically 50 copies/ml) define treatment failure.
• Transient low-level viremia ('blips') may not indicate failure, but consecutive or higher levels are associated with increased risk.

Conclusions:

• A confirmed HIV RNA >50 copies/ml is a conservative definition of treatment failure.
• A threshold of 200 copies/ml might be preferable in clinical trials to avoid false-positive failure rates.
• Variability in clinical trial endpoint definitions complicates the comparison of study results.