Is Biktarvy (bictegravir/emtricitabine/tenofovir alafenamide) a recommended regimen for HIV (Human Immunodeficiency Virus) post-exposure prophylaxis (PEP)?

Biktarvy for HIV Post-Exposure Prophylaxis

Biktarvy (bictegravir/emtricitabine/tenofovir alafenamide) is a preferred first-line regimen for HIV post-exposure prophylaxis in adults and adolescents. 1

Guideline Recommendations

The 2025 CDC guidelines explicitly list Biktarvy (BIC/FTC/TAF) as a preferred regimen for nonoccupational PEP in adults and adolescents, available as a convenient single-tablet complete regimen taken once daily for 28 days. 1 This represents a significant update from the 2015 WHO guidelines, which recommended tenofovir/emtricitabine with boosted protease inhibitors or raltegravir as the preferred approach. 1

The key advantages of Biktarvy for PEP include:

• Single-tablet regimen: One pill once daily for the full 28-day course, maximizing adherence 1, 2
• Superior tolerability: Significantly fewer gastrointestinal and systemic side effects compared to older regimens 3
• High completion rates: 90-96% completion rates in clinical studies, substantially higher than historical PEP regimens 4, 3

Initiation and Timing

Start Biktarvy as soon as possible after exposure, ideally within 24 hours but no later than 72 hours post-exposure. 1, 2 The first dose should not be delayed for pending laboratory results. 1 Perform rapid HIV testing or laboratory-based antigen/antibody combination testing before initiation, but do not wait for results to start treatment. 2, 4

Dosing Specifics

• Adults and adolescents ≥12 years: One tablet (bictegravir 50 mg/emtricitabine 200 mg/tenofovir alafenamide 25 mg) once daily for 28 days 1, 4
• Children ≥2 years and ≥14 kg: Weight-based dosing with two available tablet strengths 1
• Administration: Can be taken with or without food 5

Clinical Evidence Supporting Biktarvy

Real-world studies demonstrate exceptional performance. A Boston community health center study showed 90.4% completion rates with minimal side effects (nausea 15.4%, fatigue 9.6%, diarrhea 7.7%), with only one discontinuation due to adverse events. 3 A Chinese prospective cohort study found 97.8% completion rates and 99.6% adherence with BIC/FTC/TAF, significantly superior to multi-tablet regimens (82.6% completion, 90.2% adherence). 6 Another Chinese study reported 96.4% completion with no HIV infections through 24 weeks of follow-up. 7

Monitoring Requirements

Follow-up schedule:

• Within 72 hours: Initial evaluation after PEP initiation 2
• 4-6 weeks: HIV antigen/antibody testing plus HIV nucleic acid test (NAT) 2, 4
• 12 weeks: Final HIV testing with laboratory-based antigen/antibody combination immunoassay and HIV NAT 2, 4
• Baseline and follow-up: Renal and hepatic function tests 5

Special Considerations

Renal impairment: Tenofovir alafenamide (TAF) in Biktarvy is preferred over tenofovir disoproxil fumarate (TDF) for patients with impaired renal function due to better renal safety profile. 2

Drug interactions: Check for interactions with medications containing polyvalent cations (calcium, iron, magnesium), which can reduce bictegravir absorption. 4

Pregnancy: For pregnant women, dolutegravir with TAF/FTC is the recommended regimen rather than Biktarvy. 4

Long-acting injectable PrEP exposure: If the exposed person recently received long-acting injectable cabotegravir or rilpivirine, add HIV NAT to standard testing due to potential delayed seroconversion. 2

Transition to PrEP

After completing the 28-day PEP course, evaluate for ongoing HIV exposure risk and offer transition to pre-exposure prophylaxis (PrEP). 2, 5 Perform HIV testing at PEP completion before initiating PrEP. 2 This represents a critical opportunity to provide continuous HIV prevention for individuals with ongoing risk.

Common Pitfalls to Avoid

• Never prescribe tenofovir/emtricitabine alone without the third agent (bictegravir): Two-drug regimens provide inadequate protection. 2
• Do not delay initiation beyond 72 hours: Efficacy decreases substantially with delayed treatment. 4
• Do not stop PEP prematurely: The full 28-day course is required for maximum protection, even if side effects occur (unless severe). 1
• Do not assume PEP is single-dose: This is a 28-day commitment requiring adherence counseling. 4

Alternative Regimens

If Biktarvy is contraindicated or unavailable, the CDC recommends dolutegravir plus (tenofovir alafenamide or tenofovir disoproxil fumarate) plus (emtricitabine or lamivudine) as an equally preferred alternative. 1, 2