B/F/TAF forgiveness to non-adherence.

Area of Science:

• Virology
• Pharmacology
• Infectious Diseases

Background:

• Antiretroviral therapy (ART) forgiveness is crucial for long-term HIV management, enabling viral suppression despite imperfect adherence.
• Bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) is a commonly prescribed ART regimen.
• Understanding the forgiveness of B/F/TAF is essential for optimizing HIV treatment strategies.

Purpose of the Study:

• To evaluate the forgiveness of the bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) regimen.
• To determine the level of imperfect adherence that still allows for HIV-RNA suppression.
• To identify factors influencing virologic outcomes in patients on B/F/TAF.

Main Methods:

• Retrospective cohort study utilizing pharmacy refill data to calculate proportion of days covered (PDC) as a proxy for adherence.
• Defined forgiveness as the ability to achieve specific HIV-RNA thresholds (e.g., <200 or <50 copies/mL) at varying levels of imperfect adherence.
• Employed logistic regression to analyze the impact of baseline variables and adherence on virologic outcomes.

Main Results:

• Analysis included 420 adults with 787 one-year time-periods, demonstrating a median adherence of 0.97.
• Only 2.2% of time-periods showed HIV-RNA levels above 200 copies/mL.
• A PDC of 0.75 was sufficient for achieving viral suppression (<200 or <50 copies/mL) in over 90% of cases; an adherence of 0.85 achieved this in virtually all subjects.

Conclusions:

• Bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) exhibits significant forgiveness, maintaining HIV-RNA suppression even with suboptimal adherence.
• High forgiveness is a fundamental characteristic of effective ART regimens, contributing to improved long-term outcomes.
• B/F/TAF possesses the characteristics of an effective, well-tolerated, and forgiving ART regimen.