What is Biktarvy Used For?
Biktarvy (bictegravir/emtricitabine/tenofovir alafenamide) is a complete single-tablet antiretroviral regimen used for the treatment of HIV-1 infection in adults and children weighing at least 14 kg, either as initial therapy in treatment-naive patients or as a switch regimen in virologically suppressed patients with no known resistance to its components. 1
Primary Indication: HIV-1 Treatment
Biktarvy is FDA-approved as a three-drug fixed-dose combination containing:
- Bictegravir 50 mg (an integrase strand transfer inhibitor with a high genetic barrier to resistance) 1
- Emtricitabine 200 mg (nucleoside reverse transcriptase inhibitor) 1
- Tenofovir alafenamide 25 mg (nucleoside reverse transcriptase inhibitor) 1
The regimen is taken once daily with or without food. 1
Specific Clinical Scenarios Where Biktarvy is Recommended
Treatment-Naive Patients
Bictegravir/emtricitabine/tenofovir alafenamide is recommended as a generally recommended initial regimen for adults starting HIV treatment, with an evidence rating of AIa. 2 This recommendation is based on superior efficacy compared to efavirenz-based regimens and non-inferiority to dolutegravir-based regimens, with 88-90% of patients achieving HIV-1 RNA <50 copies/mL at 96 weeks. 3
Virologically Suppressed Patients Switching Therapy
Biktarvy is indicated to replace current antiretroviral regimens in patients who are virologically suppressed (HIV-1 RNA <50 copies/mL) on a stable regimen with no known or suspected resistance mutations to bictegravir or tenofovir. 1 The regimen maintained viral suppression in 97% of treatment-experienced patients switching from other regimens at 48 weeks. 4
HIV-1 and Hepatitis B Coinfection
Biktarvy is particularly valuable for patients coinfected with HIV-1 and hepatitis B virus (HBV) because it contains both emtricitabine and tenofovir alafenamide, which are active against HBV. 5 In a randomized trial of coinfected patients, 63% achieved HBV DNA suppression (<29 IU/mL) at 48 weeks, significantly higher than the 43% with dolutegravir/emtricitabine/tenofovir disoproxil fumarate. 6
Pediatric Patients
Biktarvy is approved for children and adolescents weighing at least 14 kg. 1 For those weighing 14-25 kg, a lower-dose formulation (30 mg bictegravir/120 mg emtricitabine/15 mg tenofovir alafenamide) is used. 1 In pediatric trials, 98% of participants maintained virological suppression at 48 weeks with excellent tolerability. 7
Pregnant Individuals
For pregnant individuals who are virologically suppressed on a stable antiretroviral regimen with no known resistance to Biktarvy's components, the standard adult dose (50/200/25 mg) is recommended once daily. 1 Dolutegravir with tenofovir alafenamide/emtricitabine (similar backbone to Biktarvy) is specifically recommended for pregnant women due to high antiviral efficacy and low rates of adverse birth outcomes. 8
Key Advantages Supporting Its Use
High Genetic Barrier to Resistance
No treatment-emergent resistance to any component of Biktarvy has been observed in clinical trials through 96 weeks, making it particularly suitable for long-term treatment. 3, 5
Minimal Drug-Drug Interactions
Bictegravir is metabolized independently of the CYP450 pathway, resulting in minimal drug interactions with medications like corticosteroids, making it ideal for patients with comorbidities requiring multiple medications. 9
Renal Safety Profile
Tenofovir alafenamide has reduced renal and bone toxicity compared to tenofovir disoproxil fumarate. 2 Biktarvy can be used in patients with creatinine clearance ≥30 mL/min, and in virologically suppressed adults with creatinine clearance <15 mL/min receiving chronic hemodialysis. 1
No HLA-B*5701 Testing Required
Unlike abacavir-containing regimens, Biktarvy does not require HLA-B*5701 testing before initiation, making it suitable for rapid-start treatment strategies. 5
Single-Tablet Convenience
Once-daily dosing as a complete regimen improves adherence, with 95% of patients continuing treatment for at least 1 year in real-world studies. 4
Important Limitations and Contraindications
Not for HIV Prevention (PrEP)
Biktarvy is NOT approved or recommended for pre-exposure prophylaxis (PrEP) to prevent HIV infection. 8 For PrEP, tenofovir disoproxil fumarate/emtricitabine remains the recommended regimen. 2
Contraindications
Biktarvy is contraindicated with:
- Dofetilide (cardiac arrhythmia medication) 1
- Rifampin (tuberculosis treatment) - significantly decreases bictegravir levels 2, 1
Not Recommended In
- Patients with estimated creatinine clearance 15 to <30 mL/min (except virologically suppressed adults on hemodialysis) 1
- Patients with creatinine clearance <15 mL/min who are treatment-naive 1
- Patients with severe hepatic impairment (Child-Pugh C) 1
- Patients with known resistance mutations to bictegravir or tenofovir 1
Critical Monitoring Requirements
Before Starting Biktarvy
- HIV testing to confirm infection 1
- Hepatitis B surface antigen testing 1
- Serum creatinine and estimated creatinine clearance 1
- Urine glucose and urine protein 1
- Serum phosphorus in patients with chronic kidney disease 1
During Treatment
- HIV-1 RNA monitoring at 1 month after initiation or switch, then every 3-6 months 10
- Renal function monitoring as clinically appropriate 1
- In patients with chronic kidney disease, also monitor serum phosphorus 1
Special Warning: Hepatitis B Exacerbation
Severe acute exacerbations of hepatitis B have been reported in patients coinfected with HIV-1 and HBV who discontinue products containing emtricitabine and/or tenofovir. 1 Hepatic function must be closely monitored for several months after discontinuation, and anti-hepatitis B therapy may be warranted. 1