Can a patient be switched from Genvoya (elvitegravir, cobicistat, emtricitabine, tenofovir alafenamide) to Biktarvy (bictegravir, emtricitabine, tenofovir alafenamide) on the same day?

Same-Day Switch from Genvoya to Biktarvy

Yes, you can switch a patient from Genvoya to Biktarvy on the same day without any washout period or lead-in dosing, provided the patient is virologically suppressed and has no documented resistance to integrase inhibitors or NRTIs. 1

Prerequisites Before Making the Switch

Before executing a same-day switch, you must verify several critical factors:

• Confirm viral suppression status with HIV-1 RNA <50 copies/mL on the current Genvoya regimen 2
• Review complete antiretroviral treatment history to identify any prior virologic failures or resistance testing results 2
• Assess for documented NRTI or integrase inhibitor resistance mutations, as these would contraindicate the switch 1, 2
• Screen for hepatitis B co-infection, as both regimens contain tenofovir alafenamide and emtricitabine, maintaining HBV suppression 2
• Evaluate renal function (eGFR) to ensure appropriateness of tenofovir alafenamide formulation 2

Why This Switch Works Seamlessly

The transition from Genvoya (elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide) to Biktarvy (bictegravir/emtricitabine/tenofovir alafenamide) is particularly straightforward because:

• Both regimens share the same NRTI backbone (emtricitabine/tenofovir alafenamide), eliminating concerns about NRTI resistance emergence during the switch 3
• Both contain integrase inhibitors with high genetic barriers to resistance, though bictegravir has demonstrated superior resistance profiles compared to elvitegravir 3
• No pharmacokinetic boosting required with Biktarvy (unlike Genvoya's cobicistat), reducing drug-drug interaction potential 1, 4
• Once-daily dosing is maintained in both regimens, preserving adherence patterns 2

Evidence Supporting This Switch Strategy

The most recent International Antiviral Society-USA 2024 guidelines explicitly support switching virologically suppressed patients from older regimens to recommended initial regimens like Biktarvy, provided virologic suppression can be maintained 1. The guidelines specifically state that individuals with virologic suppression receiving regimens containing integrase inhibitors plus 2 NRTIs can be switched to bictegravir/emtricitabine/tenofovir alafenamide regardless of likely prior NRTI resistance, provided there is no history of integrase inhibitor resistance 1.

Clinical trial data demonstrate that bictegravir-based regimens achieve 92.4% virologic suppression rates at 48 weeks with no treatment-emergent resistance observed 3. The switch is particularly advantageous because bictegravir has minimal drug-drug interactions compared to cobicistat-boosted regimens 1.

Common Reasons to Execute This Switch

Valid clinical rationales for switching from Genvoya to Biktarvy include:

• Drug-drug interactions with cobicistat in Genvoya that complicate management of comorbidities 1, 4
• Patient preference for a regimen without pharmacokinetic boosting 1
• Anticipated medication additions that interact with cobicistat (e.g., proton pump inhibitors, certain antiepileptics) 4, 5
• Simplification to a regimen with fewer interaction concerns 1

Post-Switch Monitoring Protocol

After executing the same-day switch, implement the following monitoring schedule:

• Check HIV-1 RNA at 1 month post-switch to confirm maintained viral suppression 2
• Monitor every 3 months for the first year, then at least every 6 months if stable 2
• Assess renal function (serum creatinine, eGFR) at baseline and periodically, particularly given tenofovir alafenamide content 2
• Provide adherence counseling at the time of switch to ensure understanding of the new regimen 2

Critical Pitfalls to Avoid

Several scenarios would contraindicate or complicate a same-day switch:

• Do not switch if there is any documented integrase inhibitor resistance, as this would compromise efficacy of the bictegravir-based regimen 1, 2
• Do not switch without reviewing complete resistance testing history, as archived mutations may not be apparent from current viral load alone 2
• Do not discontinue tenofovir in HBV co-infected patients without ensuring alternative HBV suppressive therapy, though this is not an issue with this specific switch since both regimens contain tenofovir alafenamide 2
• Exercise caution if eGFR <30 mL/min/1.73 m², as dose adjustments may be needed 2

The switch from Genvoya to Biktarvy represents a straightforward same-day transition that maintains the NRTI backbone while upgrading to a more potent integrase inhibitor with fewer drug interaction concerns, making it an evidence-based simplification strategy for appropriate patients 1, 3.