Alternative Antiretroviral Regimen for HIV Patient Failing Biktarvy
For a patient failing Biktarvy, switch to a boosted protease inhibitor (PI) plus 2 NRTIs (with at least 1 active NRTI determined by resistance testing), as this is the guideline-recommended approach for initial treatment failure of an integrase strand transfer inhibitor-containing regimen. 1
Immediate Steps Before Switching
- Obtain resistance testing while the patient is still taking the failing Biktarvy regimen (or within 4 weeks of stopping if already discontinued), as this is essential to guide the new regimen selection 1
- Confirm virological failure is present (defined as HIV RNA >200 copies/mL) before making treatment changes 1
- Review the patient's complete ART history, prior resistance test results, co-medications, and tolerability issues 1
Recommended Alternative Regimen Structure
The preferred approach is a boosted PI-based regimen:
- Use darunavir/ritonavir or darunavir/cobicistat as the anchor agent 1
- Combine with 2 NRTIs, ensuring at least 1 is fully active based on genotypic resistance testing 1
- The NRTI backbone selection depends on resistance patterns identified on testing 1
Important Considerations for Regimen Selection
- Never add a single active agent to the failing regimen - this is explicitly not recommended and will lead to further resistance development 1
- Integrase resistance is uncommon with bictegravir due to its high genetic barrier, but when present, requires specific management 2, 3
- If raltegravir or elvitegravir resistance mutations are detected (suggesting cross-resistance), dolutegravir dosed twice daily plus at least 1 fully active agent can be considered as an alternative to PI-based therapy 1
Special Population Considerations
For patients with HIV/HBV co-infection:
- Continue tenofovir alafenamide or tenofovir disoproxil fumarate in the new regimen unless contraindicated 1
- Switching to a regimen with lamivudine or emtricitabine but excluding tenofovir will not maintain HBV suppression 1
- Alternative HBV suppressive therapy is required if tenofovir cannot be used 1
Monitoring After Switch
- Assess HIV viral load 1 month after switching regimens to confirm virological response 1
- Continue monitoring for treatment-emergent resistance if virological suppression is not achieved 1
Common Pitfall to Avoid
The most critical error is adding only one new active drug to a failing regimen - this guarantees development of additional resistance mutations and further limits future treatment options 1. Always construct a fully suppressive regimen with multiple active agents based on resistance testing results.