What is the recommended use of Descovy (emtricitabine and tenofovir alafenamide) for treating HIV-1 infection in adults and adolescents with impaired renal function or hepatitis B infection?

Descovy (Emtricitabine/Tenofovir Alafenamide) Use in HIV-1 Treatment

Descovy is recommended as part of generally recommended initial HIV-1 treatment regimens, specifically in combination with integrase inhibitors (bictegravir or dolutegravir), and is the preferred tenofovir formulation for patients with renal impairment (CrCl 30-60 mL/min), osteopenia, or osteoporosis. 1

Primary Indications for Descovy-Based Regimens

First-Line Treatment Options

The following Descovy-containing regimens are recommended as generally preferred initial therapy for treatment-naïve adults:

• Bictegravir/TAF/emtricitabine (single-tablet regimen) 1
• Dolutegravir plus TAF/emtricitabine 1

These regimens carry the highest evidence rating (AIa) and represent optimal choices for most patients initiating HIV treatment. 1

Alternative Initial Regimens

When generally recommended regimens are unavailable or contraindicated, Descovy may be used in:

• Darunavir/cobicistat plus TAF/emtricitabine 1
• Darunavir/ritonavir plus TAF/emtricitabine 1
• Elvitegravir/cobicistat/TAF/emtricitabine (single-tablet regimen) 1
• Raltegravir plus TAF/emtricitabine 1
• Rilpivirine/TAF/emtricitabine (only if baseline HIV RNA <100,000 copies/mL and CD4 >200/μL) 1

Specific Clinical Scenarios Favoring Descovy Over TDF

Renal Impairment

Descovy is specifically indicated for patients with creatinine clearance 30-60 mL/min, whereas TDF-based regimens are contraindicated below 60 mL/min. 2, 3 This represents a critical advantage, as TAF achieves adequate antiviral efficacy with significantly lower plasma tenofovir exposure, reducing nephrotoxicity risk. 4, 5

Bone Disease

Descovy should be selected over TDF for patients with osteopenia or osteoporosis, as TAF causes less decline in bone mineral density. 1, 2, 3 Clinical trials through 144 weeks demonstrate consistently less BMD loss with TAF compared to TDF. 5

Hepatitis B Co-infection

For HIV/HBV co-infected patients, Descovy-containing regimens are recommended to maintain suppression of both viruses. 1 Both emtricitabine and tenofovir alafenamide have anti-HBV activity. 6, 7

Critical warning: When switching regimens in HBV co-infected patients, tenofovir (TAF or TDF) must be continued to prevent severe hepatitis flares or hepatic decompensation. 1, 3 If switching to a regimen without tenofovir, alternative HBV suppressive therapy is mandatory. 1

Important Contraindications and Limitations

PrEP Use Restrictions

Descovy is NOT recommended for cisgender women receiving PrEP or for event-driven "2-1-1" PrEP dosing. 2 For PrEP in cisgender women, TDF/emtricitabine (Truvada) remains the only recommended option. 2, 3

For men who have sex with men requiring PrEP with renal impairment (CrCl 30-60 mL/min) or bone disease, Descovy is the preferred choice. 2, 3

Severe Renal Impairment

Descovy is not currently recommended for patients with estimated creatinine clearance below 30 mL/min, though it appears safe down to CrCl 15 mL/min. 5 In such cases, alternative regimens should be considered.

Hepatic Impairment

TAF is not recommended in patients with moderate or severe hepatic impairment (Child-Pugh class B or C). 5

Monitoring Requirements

Pre-Treatment Testing

Before initiating any Descovy-containing regimen, obtain:

• HIV testing with combination antigen-antibody assay (add HIV RNA if acute infection suspected) 2, 3
• Serum creatinine and estimated creatinine clearance 2, 3
• Hepatitis B surface antigen (HBsAg) 2, 3
• Hepatitis C antibody 2, 3
• HLA-B*5701 testing (only if abacavir-containing regimen is being considered as alternative) 1

Ongoing Monitoring Schedule

• HIV RNA level: Within 6 weeks of starting treatment, then every 3 months until <50 copies/mL for 1 year, then every 6 months 1, 2
• CD4 count: Every 6 months until >250/μL for 1 year, then can discontinue if virus remains suppressed 1
• Serum creatinine/eGFR: Every 6-12 months for most patients 2, 3
• More frequent renal monitoring (every 3-6 months) for patients >50 years, taking hypertension/diabetes medications, or baseline eGFR <90 mL/min 2

Drug-Drug Interactions

Review co-medications to ensure no TAF dosing adjustment is needed, as certain medications may require dose modifications. 1 TAF is more stable in plasma than TDF, leading to different interaction profiles. 4

Switching to Descovy-Based Regimens

In Virologically Suppressed Patients

Patients with viral suppression may switch to Descovy-based regimens provided both agents remain fully active and no resistance mutations are present. 1 Review prior resistance testing and treatment history before switching. 1

For HBV co-infected patients switching regimens, tenofovir (TAF or TDF) must be continued. 1 Switching to lamivudine or emtricitabine alone without tenofovir will not maintain HBV suppression. 1

Pregnancy Considerations

Pregnant individuals with HIV should initiate antiretroviral therapy for their own health and to reduce transmission risk. 1 Dolutegravir plus TAF/emtricitabine has supporting data for use during pregnancy. 1

Advantages Over TDF-Based Regimens

• Lower plasma tenofovir exposure reduces nephrotoxicity and bone density loss 4, 5
• Usable in moderate renal impairment (CrCl 30-60 mL/min) where TDF is contraindicated 2, 3, 5
• Better bone safety profile with less BMD decline through 144 weeks 5
• Equivalent virologic efficacy to TDF with improved safety 4, 5, 7