Can a patient with HIV-1 infection, currently on Epzicom (abacavir/lamivudine) and dolutegravir, be switched to Biktarvy (bictegravir/emtricitabine/tenofovir alafenamide)?

Switching from Epzicom and Dolutegravir to Biktarvy

Yes, a virologically suppressed patient on Epzicom (abacavir/lamivudine) and dolutegravir can be switched to Biktarvy (bictegravir/emtricitabine/tenofovir alafenamide), provided they meet specific criteria including documented viral suppression (HIV-1 RNA <50 copies/mL), no known resistance to bictegravir or tenofovir, and appropriate renal function. 1

Prerequisites That Must Be Confirmed Before Switching

Treatment history and resistance testing review:

• Review complete antiretroviral treatment history to confirm no prior virologic failure on integrase inhibitor or tenofovir-containing regimens 2, 3
• Confirm results of all prior resistance testing show no integrase strand transfer inhibitor (INSTI) or nucleoside reverse transcriptase inhibitor (NRTI) resistance mutations 3, 2
• If resistance testing history is unavailable, consider proviral DNA genotyping to detect archived mutations, though this is not routinely required for patients without documented virologic failure 2

Current virologic status:

• Confirm HIV-1 RNA <50 copies/mL on current stable regimen 1
• The FDA label specifically indicates Biktarvy is approved "to replace the current antiretroviral regimen in those who are virologically suppressed" 1

Hepatitis B screening:

• Assess hepatitis B virus (HBV) co-infection status before switching 1, 3
• If HBV co-infected, switching to Biktarvy is actually advantageous since it contains tenofovir alafenamide and emtricitabine, both active against HBV, maintaining required HBV suppression 2
• Critical warning: Never discontinue tenofovir-containing regimens in HBV co-infected patients without alternative HBV therapy, as severe hepatitis flares can occur 1, 4

Renal function assessment:

• Measure serum creatinine and estimated creatinine clearance (eCrCl) 1, 3
• Biktarvy is approved for eCrCl ≥30 mL/min 1
• Biktarvy is NOT recommended for eCrCl 15 to <30 mL/min, or <15 mL/min in patients not on chronic hemodialysis 1
• Assess urine glucose and urine protein as clinically appropriate 1

Why This Switch Is Guideline-Supported

High-quality evidence supports switching to Biktarvy:

• The 2025 International Antiviral Society-USA guidelines explicitly state that individuals with virologic suppression receiving any regimen can switch to bictegravir/emtricitabine/tenofovir alafenamide (one of the recommended initial regimens), provided there is no history of INSTI resistance 2
• Prospective clinical trials demonstrate that virologically suppressed patients can switch to bictegravir/emtricitabine/tenofovir alafenamide regardless of likely prior NRTI resistance, provided no INSTI resistance exists 2

Advantages of switching to Biktarvy:

• Single-tablet regimen improves convenience and adherence 2, 5
• No HLA-B*5701 testing required (unlike abacavir in Epzicom), making it suitable for rapid treatment modifications 5, 6
• High genetic barrier to resistance with no treatment-emergent resistance observed in clinical trials 2, 5, 6
• Tenofovir alafenamide has superior renal and bone safety profile compared to tenofovir disoproxil fumarate 2
• Fulfills treatment requirements for HBV co-infection 5
• Minimal drug-drug interactions compared to boosted protease inhibitor regimens 3

Clinical Trial Evidence Supporting This Switch

Switch study data:

• In a randomized trial of 563 virologically suppressed patients switching from dolutegravir/abacavir/lamivudine to bictegravir/emtricitabine/tenofovir alafenamide, only 1% had HIV-1 RNA ≥50 copies/mL at week 48, demonstrating non-inferiority 7
• At 96 weeks, 88% maintained HIV-1 RNA <50 copies/mL with no treatment-emergent resistance 8
• Five-year follow-up data show 98.6% of patients with available data maintained viral suppression, with only 1.6% discontinuing due to adverse events 9
• Treatment-related adverse events were actually less common with bictegravir/emtricitabine/tenofovir alafenamide (8%) compared to dolutegravir/abacavir/lamivudine (16%) in switch studies 7

Post-Switch Monitoring Protocol

Virologic monitoring:

• Check HIV-1 RNA at 1 month after switch to confirm maintained viral suppression 2, 3
• Monitor HIV-1 RNA every 3 months for the first year, then every 6 months if stable 3, 4
• More frequent monitoring is reasonable if there are adherence concerns 2

Safety monitoring:

• Monitor renal function (serum creatinine, eCrCl) periodically, particularly in patients with baseline renal impairment 1, 3
• Assess bone density if risk factors present, though tenofovir alafenamide has better bone safety than tenofovir disoproxil fumarate 3
• Monitor lipids, as modest increases may occur (loss of lipid-lowering effect seen with some prior regimens) 2
• Monitor weight, as median weight gain of 6.1 kg was observed at 5 years 9

HBV monitoring if co-infected:

• Continue monitoring HBV DNA and liver function tests 1
• If Biktarvy is ever discontinued in HBV co-infected patients, closely monitor hepatic function for several months and consider alternative HBV therapy 1

Critical Contraindications and Precautions

Absolute contraindications:

• Do NOT switch if patient is taking dofetilide (risk of serious cardiac arrhythmias) 1
• Do NOT switch if patient is taking rifampin (significant drug interaction reducing bictegravir levels) 1

Relative contraindications:

• Do NOT switch if eCrCl <30 mL/min (unless on chronic hemodialysis with eCrCl <15 mL/min) 1
• Do NOT switch if severe hepatic impairment present 1
• Exercise caution if documented INSTI or tenofovir resistance mutations exist 2, 1

Drug interactions requiring dose timing adjustments:

• If taking aluminum or magnesium-containing antacids: take Biktarvy at least 2 hours before or 6 hours after antacids 1
• If taking iron or calcium supplements: take Biktarvy with food at the same time as these supplements 1

Special Populations

Pregnancy:

• Biktarvy can be continued in pregnant individuals who are virologically suppressed on this regimen, though dolutegravir with tenofovir alafenamide/emtricitabine remains the preferred first-line regimen in pregnancy 2
• Bictegravir is an alternative regimen in pregnancy with reassuring pharmacokinetic data and low rates of birth defects 2

Older guidelines context:

• Earlier 2020 guidelines were more cautious about switching from high-barrier regimens (like dolutegravir-based therapy) without complete resistance history 2
• However, the most recent 2025 guidelines explicitly support this switch in virologically suppressed patients without INSTI resistance 2