RECENT MAJOR CHANGES SECTION

RECENT MAJOR CHANGES

DESCRIPTION SECTION

11 DESCRIPTION

BIKTARVY (bictegravir, emtricitabine, and tenofovir alafenamide) is a fixed dose combination tablet containing bictegravir (BIC), emtricitabine (FTC), and tenofovir alafenamide (TAF) for oral administration.

• BIC is an integrase strand transfer inhibitor (INSTI).
• FTC, a synthetic nucleoside analog of cytidine, is an HIV nucleoside analog reverse transcriptase inhibitor (HIV NRTI).
• TAF, an HIV NRTI, is converted in vivo to tenofovir, an acyclic nucleoside phosphonate (nucleotide) analog of adenosine 5′-monophosphate.

BIKTARVY tablets are available in two dose strengths:

• 50 mg/200 mg/25 mg tablet containing 50 mg of BIC (equivalent to 52.5 mg of bictegravir sodium),
  200 mg of FTC, and 25 mg of TAF (equivalent to 28 mg of tenofovir alafenamide fumarate).

• 30 mg/120 mg/15 mg tablet containing 30 mg of BIC (equivalent to 31.5 mg of bictegravir sodium), 120 mg of FTC, and 15 mg of TAF (equivalent to 16.8 mg of tenofovir alafenamide fumarate).

Both dose strengths of BIKTARVY tablets include the following inactive ingredients: croscarmellose sodium, magnesium stearate, and microcrystalline cellulose. The tablets for both dose strengths are film-coated with a coating material containing iron oxide black, iron oxide red, polyethylene glycol, polyvinyl alcohol, talc, and titanium dioxide.

Bictegravir: The chemical name of bictegravir sodium is 2,5-Methanopyrido[1',2':4,5]pyrazino[2,1-b][1,3]oxazepine-10-carboxamide, 2,3,4,5,7,9,13,13a-octahydro-8-hydroxy-7,9-dioxo-N-[(2,4,6-trifluorophenyl)methyl]-, sodium salt (1:1), (2R,5S,13aR)-.

Bictegravir sodium has a molecular formula of C21H17F3N3NaO5 and a molecular weight of 471.4 and has the following structural formula:

Bictegravir sodium is an off-white to yellow solid with a solubility of 0.1 mg per mL in water at 20 °C.

Emtricitabine: The chemical name of FTC is 4-amino-5-fluoro-1-(2R-hydroxymethyl-1,3-oxathiolan-5S-yl)-(1H)-pyrimidin-2-one. FTC is the (-)enantiomer of a thio analog of cytidine, which differs from other cytidine analogs in that it has a fluorine in the 5 position.

FTC has a molecular formula of C8H10FN3O3S and a molecular weight of 247.2 and has the following structural formula:

FTC is a white to off-white powder with a solubility of approximately 112 mg per mL in water at 25 °C.

Tenofovir alafenamide: The chemical name of tenofovir alafenamide fumarate drug substance is L-alanine, N-[(S)-[[(1R)-2-(6-amino-9H-purin-9-yl)-1-methylethoxy]methyl]phenoxyphosphinyl]-, 1-methylethyl ester, (2E)-2-butenedioate (2:1).

Tenofovir alafenamide fumarate has an empirical formula of C21H29O5N6P∙½(C4H4O4) and a formula weight of 534.5 and has the following structural formula:

Tenofovir alafenamide fumarate is a white to off-white or tan powder with a solubility of 4.7 mg per mL in water at 20 °C.

CLINICAL PHARMACOLOGY SECTION

12 CLINICAL PHARMACOLOGY

12.1 Mechanism of Action

BIKTARVY is a fixed dose combination of antiretroviral drugs bictegravir (BIC), emtricitabine (FTC), and tenofovir alafenamide (TAF) [see Microbiology (12.4)].

12.2 Pharmacodynamics

Cardiac Electrophysiology

In a thorough QT/QTc trial in 48 healthy subjects, BIC at doses 1.5 and 6 times the recommended dose did not affect the QT/QTc interval and did not prolong the PR interval. In a thorough QT/QTc trial in 48 healthy subjects, TAF at the recommended dose or at a dose 5 times the recommended dose, did not affect the QT/QTc interval and did not prolong the PR interval. The effect of FTC on the QT interval is not known.

Effects on Serum Creatinine

Mean change from baseline in serum creatinine in healthy subjects who received BIC 75 mg (1.5 times the approved recommended dosage) once daily with food for 14 days was 0.1 mg per dL on Days 7 and 14 compared to placebo. BIC did not have a significant effect on the estimated creatinine clearance or on the actual glomerular filtration rate (determined by the clearance of probe drug, iohexol).

12.3 Pharmacokinetics

The pharmacokinetic (PK) properties of BIKTARVY components are provided in Table 4. The multiple dose PK parameters of BIKTARVY components (based on population pharmacokinetic analysis) are provided in Table 5.

Specific Populations

Patients with Renal Impairment

No clinically relevant differences in the pharmacokinetics of BIC, TAF, or its metabolite tenofovir were observed between subjects with severe renal impairment (estimated creatinine clearance of 15 to less than 30 mL/min, by Cockcroft-Gault method) and healthy subjects in Phase 1 studies. In a separate Phase 1 study of FTC alone, FTC exposures were increased in subjects with severe renal impairment.

The pharmacokinetics of BIC, FTC and TAF were evaluated in a subset of HIV-1 infected virologically-suppressed subjects with ESRD (estimated creatinine clearance less than 15 mL/min, by Cockcroft-Gault method) receiving chronic hemodialysis in Trial 1825. The pharmacokinetics of TAF were similar between healthy subjects and subjects with ESRD receiving chronic hemodialysis; increases in FTC and tenofovir exposures in subjects with ESRD were not considered clinically relevant. Median (minimum, maximum) BIC Ctrough values in subjects (n=7) with ESRD who received BIKTARVY were 846 ng/mL (288, 1810) compared to 2540 ng/mL (757, 6499) in subjects (N=584) with normal renal function. Despite significantly lower BIC Ctrough values in the virologically- suppressed ESRD population, virologic suppression was maintained [see Use in Specific Populations (8.6), and Clinical Studies (14.3)].

Patients with Hepatic Impairment

Bictegravir: Clinically relevant changes in the pharmacokinetics of BIC were not observed in subjects with moderate (Child-Pugh Class B) hepatic impairment.

Emtricitabine: The pharmacokinetics of FTC has not been studied in subjects with hepatic impairment; however, FTC is not significantly metabolized by liver enzymes, so the impact of hepatic impairment should be limited.

Tenofovir Alafenamide: Clinically relevant changes in the pharmacokinetics of TAF or its metabolite tenofovir were not observed in subjects with mild or moderate (Child-Pugh Class A and B) hepatic impairment [see Use in Specific Populations (8.7)].

Hepatitis B and/or Hepatitis C Virus Coinfection

The pharmacokinetics of BIC, FTC, and TAF have not been evaluated in subjects coinfected with hepatitis B and/or C virus.

Geriatric Patients

The pharmacokinetics of BIC, FTC, and TAF have not been fully evaluated in the elderly (65 years of age and older). Population pharmacokinetics analysis of HIV-infected subjects in Phase 3 trials of BIKTARVY showed that age did not have a clinically relevant effect on exposures of BIC and TAF up to 74 years of age [see Use in Specific Populations (8.5)].

Pediatric Patients

Mean BIC Ctrough was lower in 50 pediatric patients aged 12 to less than 18 years and weighing at least 35 kg who received BIKTARVY in Trial 1474 relative to adults following administration of BIKTARVY, but was not considered clinically significant based on exposure-response relationships; exposures of FTC and TAF in these pediatric patients were similar to those in adults (Table 6).

Mean BIC Cmax, and exposures of FTC and TAF (AUCtau and Cmax) achieved in 50 pediatric patients between the ages of 6 to less than 12 years and weighing at least 25 kg, and in 22 pediatric patients at least 2 years of age and weighing at least 14 to less than 25 kg who received BIKTARVY in Trial 1474 were higher than exposures in adults; however, the increases were not considered clinically significant as the safety profiles were similar in adult and pediatric patients (Tables 7 and 8) [see Use in Specific Populations (8.4)].

Race and Gender

No clinically relevant changes in the pharmacokinetics of BIC, FTC, and TAF were observed based on gender or race.

Drug Interaction Studies

As BIKTARVY is a complete regimen for the treatment of HIV-1 infection, comprehensive information regarding potential drug-drug interactions with other antiretroviral agents is not provided.

BIC is a substrate of CYP3A and UGT1A1.

BIC is an inhibitor of OCT2 and MATE1. At clinically relevant concentrations, BIC is not an inhibitor of hepatic transporters OATP1B1, OATP1B3, OCT1, BSEP, renal transporters OAT1 and OAT3, or CYP (including CYP3A) or UGT1A1 enzymes.

TAF is a substrate of P-gp and BCRP.

At clinically relevant concentrations, TAF is not an inhibitor of drug transporters P-gp, BCRP, hepatic transporters OATP1B1, OATP1B3, OCT1, BSEP, renal transporters OAT1, OAT3, OCT2, MATE1, or CYP (including CYP3A) or UGT1A1 enzymes.

Drug interaction studies were conducted with BIKTARVY or its components. Tables 9 and 10 summarize the pharmacokinetic effects of other drugs on BIC and TAF, respectively. Table 11 summarizes the pharmacokinetic effects of BIKTARVY or its components on other drugs.

Effect of Other Drugs on BIKTARVY Components

Effect of BIKTARVY Components on Other Drugs

12.4 Microbiology

Mechanism of Action

Bictegravir: BIC inhibits the strand transfer activity of HIV-1 integrase (integrase strand transfer inhibitor; INSTI), an HIV-1 encoded enzyme that is required for viral replication. Inhibition of integrase prevents the integration of linear HIV-1 DNA into host genomic DNA, blocking the formation of the HIV-1 provirus and propagation of the virus.

Emtricitabine: FTC, a synthetic nucleoside analog of cytidine, is phosphorylated by cellular enzymes to form emtricitabine 5'-triphosphate. Emtricitabine 5'-triphosphate inhibits the activity of the HIV-1 RT by competing with the natural substrate deoxycytidine 5'-triphosphate and by being incorporated into nascent viral DNA which results in chain termination. Emtricitabine 5′-triphosphate is a weak inhibitor of mammalian DNA polymerases α, β, Ɛ, and mitochondrial DNA polymerase γ.

Tenofovir Alafenamide: TAF is a phosphonamidate prodrug of tenofovir (2′-deoxyadenosine monophosphate analog). Plasma exposure to TAF allows for permeation into cells and then TAF is intracellularly converted to tenofovir through hydrolysis by cathepsin A. Tenofovir is subsequently phosphorylated by cellular kinases to the active metabolite tenofovir diphosphate. Tenofovir diphosphate inhibits HIV-1 replication through incorporation into viral DNA by the HIV RT, which results in DNA chain-termination. Tenofovir diphosphate is a weak inhibitor of mammalian DNA polymerases that include mitochondrial DNA polymerase γ and there is no evidence of toxicity to mitochondria in cell culture.

Antiviral Activity in Cell Culture

The triple combination of BIC, FTC, and TAF was not antagonistic with respect to antiviral activity in cell culture.

Bictegravir: The antiviral activity of BIC against laboratory and clinical isolates of HIV-1 was assessed in lymphoblastoid cell lines, PBMCs, primary monocyte/macrophage cells, and CD4+ T-lymphocytes. In MT-4 cells (human lymphoblastoid T-cell line) acutely infected with HIV-1 IIIB, the mean 50% effective concentration (EC50) was 2.4±0.4 nM, and the protein-adjusted EC95 value was 361 nM (0.162 micrograms per mL). BIC displayed antiviral activity in activated PBMCs against clinical isolates of HIV-1 representing groups M, N, and O, including subtypes A, B, C, D, E, F, and G, with a median EC50 value of 0.55 nM (range <0.05 to 1.71 nM). The EC50 value against a single HIV-2 isolate was 1.1 nM.

Emtricitabine: The antiviral activity of FTC against laboratory and clinical isolates of HIV-1 was assessed in T lymphoblastoid cell lines, the MAGI-CCR5 cell line, and PBMCs. In PBMCs acutely infected with HIV-1 subtypes A, B, C, D, E, F, and G, the median EC50 value for FTC was 9.5 nM (range 1 to 30 nM) and against HIV-2 was 7 nM.

Tenofovir Alafenamide: The antiviral activity of TAF against laboratory and clinical isolates of HIV-1 subtype B was assessed in lymphoblastoid cell lines, PBMCs, primary monocyte/macrophage cells and CD4-T lymphocytes. The EC50 values for TAF ranged from 2.0 to 14.7 nM. TAF displayed antiviral activity in cell culture against all HIV-1 groups (M, N, O), including subtypes A, B, C, D, E, F, and G (EC50 values ranged from 0.1 to 12 nM) and strain specific activity against HIV-2 (EC50 values ranged from 0.9 to 2.6 nM).

Resistance

In Cell Culture

Bictegravir: HIV-1 isolates with reduced susceptibility to BIC have been selected in cell culture. In one selection with BIC, a virus pool emerged expressing amino acid substitutions M50I and R263K in the HIV-1 integrase. M50I, R263K, and M50I+R263K substitutions, when introduced into a wild-type virus by site-directed mutagenesis, conferred 1.3-, 2.2-, and 2.9-fold reduced susceptibility to BIC, respectively. In a second selection, emergence of amino acid substitutions T66I and S153F was detected, and 0.4-, 1.9-, and 0.5-fold reductions in BIC susceptibility were observed with T66I, S153F, and T66I+S153F, respectively. In addition, S24G and E157K substitutions emerged during the selection process.

Emtricitabine: HIV-1 isolates with reduced susceptibility to FTC were selected in cell culture and in subjects treated with FTC. Reduced susceptibility to FTC was associated with M184V or I substitutions in HIV-1 RT.

Tenofovir Alafenamide: HIV-1 isolates with reduced susceptibility to TAF were selected in cell culture. HIV-1 isolates selected by TAF expressed a K65R substitution in HIV-1 RT, sometimes in the presence of S68N or L429I substitutions; in addition, a K70E substitution in HIV-1 RT was observed.

In Clinical Trials

In Subjects with No Antiretroviral Treatment History: Pooled results of genotypic resistance analyses were performed on paired baseline and on- treatment HIV-1 isolates from subjects receiving BIKTARVY in Trials 1489 and 1490 through Week 144 of the double-blind phase (N=634) or Week 96 of the extension phase (n=1025) [see Clinical Studies (14.2)] who had HIV-1 RNA greater than or equal to 200 copies/mL at the time of confirmed virologic failure or early study drug discontinuation. In the final resistance analysis population, no specific amino acid substitutions emerged consistently in the 11 treatment failure subjects with evaluable genotypic resistance data and failed to establish an association with genotypic BIC resistance. There were no treatment-emergent NRTI resistance-associated substitutions detected in the 11 evaluated treatment failure isolates. Phenotypic resistance analyses of failure isolates found fold-changes in drug susceptibility below the biological or clinical cutoffs for BIC, FTC, and TFV, compared to wild-type reference HIV-1.

In Virologically Suppressed Adult Subjects: In 2 of the switch trials, Trials 1844 and 1878, of virologically suppressed HIV-1 infected subjects (n=572), only one subject with virologic rebound in the resistance analysis population had IN genotypic and phenotypic data, and 2 rebounders had RT genotypic and phenotypic data. No subjects had HIV-1 with treatment-emergent genotypic or phenotypic resistance to BIC, FTC, or TAF. In Trial 4030, no subjects receiving BIKTARVY had treatment-emergent phenotypic resistance to BIC, FTC, or TAF.

In Virologically Suppressed Pediatric Subjects: In Trial 1474 [see Clinical Studies (14.4)], two of 50 subjects in cohort 1 were evaluated for the development of resistance through Week 48; no amino acid substitutions known to be associated with resistance to BIC, FTC, or TFV were detected. No subjects in cohort 2 or 3 met the criteria for resistance analyses through Week 24.

Cross-Resistance

Bictegravir: Cross-resistance has been observed among INSTIs. The susceptibility of BIC was tested against 64 clinical isolates expressing known INSTI resistance-associated substitutions listed by IAS-USA (20 with single substitutions and 44 with 2 or more substitutions). Isolates with a single INSTI-resistance substitution including E92Q, T97A, Y143C/R, Q148R, and N155H showed less than 2-fold reduced susceptibility to BIC. All isolates (n=14) with more than 2.5-fold reduced susceptibility to BIC (above the biological cutoff for BIC) contained G140A/C/S and Q148H/R/K substitutions; the majority (64.3%, 9/14) had a complex INSTI resistance pattern with an additional INSTI- resistance substitution L74M, T97A, or E138A/K. Of those evaluated isolates containing G140A/C/S and Q148H/R/K substitutions in the absence of additional INSTI-resistance substitutions, 38.5% (5/13) showed more than 2.5-fold reduction. In addition, site-directed mutant viruses with G118R (dolutegravir and raltegravir treatment-emergent substitution) and G118R+T97A had 3.4- and 2.8-fold reduced susceptibility to BIC, respectively.

BIC demonstrated equivalent antiviral activity with less than 2-fold reductions in susceptibility against HIV-1 variants expressing substitutions associated with resistance to NNRTIs, NRTIs, and PIs, compared with the wild- type virus.

Emtricitabine: Cross-resistance has been observed among NRTIs. FTC-resistant viruses with an M184V/I substitution in HIV-1 RT were cross-resistant to lamivudine. HIV-1 isolates containing the K65R RT substitution, selected in vivo by abacavir, didanosine, and tenofovir, demonstrated reduced susceptibility to inhibition by FTC.

Tenofovir Alafenamide: Cross-resistance has been observed among NRTIs. Tenofovir resistance substitutions K65R and K70E result in reduced susceptibility to abacavir, didanosine, emtricitabine, lamivudine, and tenofovir. HIV-1 with multiple thymidine analog substitutions (M41L, D67N, K70R, L210W, T215F/Y, K219Q/E/N/R), or multinucleoside resistant HIV-1 with a T69S double insertion mutation or with a Q151M substitution complex including K65R, showed reduced susceptibility to TAF in cell culture.

INDICATIONS & USAGE SECTION

Highlight: BIKTARVY is a three-drug combination of bictegravir (BIC), a human immunodeficiency virus type 1 (HIV-1) integrase strand transfer inhibitor (INSTI), and emtricitabine (FTC) and tenofovir alafenamide (TAF), both HIV-1 nucleoside analog reverse transcriptase inhibitors (NRTIs), and is indicated as a complete regimen for the treatment of HIV-1 infection in adults and pediatric patients weighing at least 14 kg:

• who have no antiretroviral treatment history or
• to replace the current antiretroviral regimen in those who are virologically suppressed (HIV-1 RNA less than 50 copies per mL) on a stable antiretroviral regimen with no known or suspected substitutions associated with resistance to bictegravir or tenofovir. (1)

1 INDICATIONS AND USAGE

BIKTARVY is indicated as a complete regimen for the treatment of human immunodeficiency virus type 1 (HIV-1) infection in adults and pediatric patients weighing at least 14 kg:

• who have no antiretroviral treatment history or
• to replace the current antiretroviral regimen in those who are virologically-suppressed (HIV-1 RNA less than 50 copies per mL) on a stable antiretroviral regimen with no known or suspected substitutions associated with resistance to bictegravir or tenofovir.

DOSAGE FORMS & STRENGTHS SECTION

Highlight: Tablets: 50 mg of BIC, 200 mg of FTC, and 25 mg of TAF. (3)

Tablets: 30 mg of BIC, 120 mg of FTC, and 15 mg of TAF. (3)

3 DOSAGE FORMS AND STRENGTHS

BIKTARVY tablets are available in two dose strengths:

• 50 mg/200 mg/25 mg tablets: 50 mg of bictegravir (BIC) (equivalent to 52.5 mg of bictegravir sodium), 200 mg of emtricitabine (FTC), and 25 mg of tenofovir alafenamide (TAF) (equivalent to 28 mg of tenofovir alafenamide fumarate). These tablets are purplish brown, capsule-shaped, film-coated, and debossed with "GSI" on one side and "9883" on the other side.
• 30 mg/120 mg/15 mg tablets: 30 mg of BIC (equivalent to 31.5 mg of bictegravir sodium), 120 mg of FTC, and 15 mg of TAF (equivalent to 16.8 mg of tenofovir alafenamide fumarate). These tablets are pink, capsule-shaped, film-coated, and debossed with "GSI" on one side and "B" on the other side.

CONTRAINDICATIONS SECTION

Highlight: BIKTARVY is contraindicated to be co-administered with:

• dofetilide. (4)
• rifampin. (4)

4 CONTRAINDICATIONS

BIKTARVY is contraindicated to be co-administered with:

• dofetilide due to the potential for increased dofetilide plasma concentrations and associated serious and/or life-threatening events [see Drug Interactions (7.5)].
• rifampin due to decreased BIC plasma concentrations, which may result in the loss of therapeutic effect and development of resistance to BIKTARVY [see Drug Interactions (7.5)].

BOXED WARNING SECTION

WARNING: POST TREATMENT ACUTE EXACERBATION OF HEPATITIS B

DRUG INTERACTIONS SECTION

Highlight: * Because BIKTARVY is a complete regimen, coadministration with other antiretroviral medications for the treatment of HIV-1 infection is not recommended. (7.1)

• Consult the Full Prescribing Information prior to and during treatment for important drug interactions. (4, 5.2, 7, 12.3)

7 DRUG INTERACTIONS

7.1 Other Antiretroviral Medications

Because BIKTARVY is a complete regimen, coadministration with other antiretroviral medications for the treatment of HIV-1 infection is not recommended [see Indications and Usage (1)]. Comprehensive information regarding potential drug-drug interactions with other antiretroviral medications is not provided because the safety and efficacy of concomitant HIV-1 antiretroviral therapy is unknown.

7.2 Potential for BIKTARVY to Affect Other Drugs

BIC inhibits organic cation transporter 2 (OCT2) and multidrug and toxin extrusion transporter 1 (MATE1) in vitro. Coadministration of BIKTARVY with drugs that are substrates of OCT2 and MATE1 (e.g., dofetilide) may increase their plasma concentrations (see Table 3).

7.3 Potential Effect of Other Drugs on One or More Components of BIKTARVY

BIC is a substrate of CYP3A and UGT1A1. A drug that is a strong inducer of CYP3A and also an inducer of UGT1A1 can substantially decrease the plasma concentrations of BIC which may lead to loss of therapeutic effect of BIKTARVY and development of resistance [see Clinical Pharmacology (12.3)].

The use of BIKTARVY with a drug that is a strong inhibitor of CYP3A and also an inhibitor of UGT1A1 may significantly increase the plasma concentrations of BIC.

TAF is a substrate of P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP). Co-administration of drugs that inhibit P-gp and BCRP may increase the absorption and plasma concentrations of TAF [see Clinical Pharmacology (12.3)]. Co-administration of drugs that induce P-gp activity are expected to decrease the absorption of TAF, resulting in decreased plasma concentration of TAF, which may lead to loss of therapeutic effect of BIKTARVY and development of resistance (see Table 3).

7.4 Drugs Affecting Renal Function

Because FTC and tenofovir are primarily excreted by the kidneys by a combination of glomerular filtration and active tubular secretion, coadministration of BIKTARVY with drugs that reduce renal function or compete for active tubular secretion may increase concentrations of FTC, tenofovir, and other renally eliminated drugs and this may increase the risk of adverse reactions. Some examples of drugs that are eliminated by active tubular secretion include, but are not limited to, acyclovir, cidofovir, ganciclovir, valacyclovir, valganciclovir, aminoglycosides (e.g., gentamicin), and high- dose or multiple NSAIDs [see Warnings and Precautions (5.4)].

7.5 Established and Potentially Significant Drug Interactions

Table 3 provides a listing of established or potentially clinically significant drug interactions with recommended prevention or management strategies. The drug interactions described are based on studies conducted with either BIKTARVY, the components of BIKTARVY (BIC, FTC, and TAF) as individual agents, or are drug interactions that may occur with BIKTARVY [see Contraindications (4), Warnings and Precautions (5.2), and Clinical Pharmacology (12.3)].

7.6 Drugs without Clinically Significant Interactions with BIKTARVY

Based on drug interaction studies conducted with BIKTARVY or the components of BIKTARVY, no clinically significant drug interactions have been observed when BIKTARVY is combined with the following drugs: ethinyl estradiol, ledipasvir/sofosbuvir, midazolam, norgestimate, sertraline, sofosbuvir, sofosbuvir/velpatasvir, and sofosbuvir/velpatasvir/voxilaprevir.

ADVERSE REACTIONS SECTION

Highlight: Most common adverse reactions (incidence greater than or equal to 5%, all grades) are diarrhea, nausea, and headache. (6.1)

To report SUSPECTED ADVERSE REACTIONS, contact Gilead Sciences, Inc. at 1-800-GILEAD-5 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

6 ADVERSE REACTIONS

The following adverse reactions are discussed in other sections of the labeling:

• Severe Acute Exacerbations of Hepatitis B [see Warnings and Precautions (5.1)].
• Immune Reconstitution Syndrome [see Warnings and Precautions (5.3)].
• New Onset or Worsening Renal Impairment [see Warnings and Precautions (5.4)].
• Lactic Acidosis/Severe Hepatomegaly with Steatosis [see Warnings and Precautions (5.5)].

6.1 Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

Clinical Trials in Adults with No Antiretroviral Treatment History

The primary safety assessment of BIKTARVY was based on data from two randomized, double-blind, active-controlled trials, Trial 1489 and Trial 1490, that enrolled 1274 HIV-1 infected adult subjects with no antiretroviral treatment history through Week 144. After Week 144, subjects received open- label BIKTARVY in an optional extension phase for an additional 96 weeks (end of study). A total of 634 and 1025 subjects received one tablet of BIKTARVY once daily during the double-blind (Week 144) and extension phases, respectively [see Clinical Studies (14.2)].

The most common adverse reactions (all Grades) reported in at least 5% of subjects in the BIKTARVY group in either Trial 1489 or Trial 1490 were diarrhea, nausea, and headache. The proportion of subjects who discontinued treatment through Week 144 with BIKTARVY, abacavir [ABC]/dolutegravir [DTG]/ lamivudine [3TC]), or DTG + FTC/TAF, due to adverse events, regardless of severity, was 1%, 2%, and 2%, respectively. Table 1 displays the frequency of adverse reactions (all Grades) greater than or equal to 2% in the BIKTARVY group.

Additional adverse reactions (all Grades) occurring in less than 2% of subjects administered BIKTARVY in Trials 1489 and 1490 included vomiting, flatulence, dyspepsia, abdominal pain, rash, and depression.

Suicidal ideation, suicide attempt, and depression suicidal occurred in 2% of subjects administered BIKTARVY; these events occurred primarily in subjects with a preexisting history of depression, prior suicide attempt or psychiatric illness.

The majority (84%) of adverse events associated with BIKTARVY were Grade 1.

Adverse reactions in the open-label extension phases of Trials 1489 and 1490 were similar to those observed in subjects administered BIKTARVY in the Week 144 analysis.

Clinical Trials in Virologically Suppressed Adults

The safety of BIKTARVY in virologically-suppressed adults was based on Week 48 data from 282 subjects in a randomized, double-blind, active-controlled trial (Trial 1844) in which virologically-suppressed subjects were switched from either DTG + ABC/3TC or ABC/DTG/3TC to BIKTARVY; Week 48 data from 290 subjects in an open-label, active-controlled trial in which virologically- suppressed subjects were switched from a regimen containing atazanavir (ATV) (given with cobicistat or ritonavir) or darunavir (DRV) (given with cobicistat or ritonavir) plus either FTC/TDF or ABC/3TC, to BIKTARVY (Trial 1878); and Week 48 data from a randomized, double-blind active-controlled trial in which 284 virologically-suppressed subjects were switched from DTG plus either FTC/TAF or FTC/TDF, to BIKTARVY (Trial 4030). Overall, the safety profile in virologically-suppressed adult subjects in Trials 1844, 1878, and 4030 was similar to that in subjects with no antiretroviral treatment history [see Clinical Studies (14.3)].

Clinical Trial in Adults with End Stage Renal Disease (ESRD) Receiving Chronic Hemodialysis

The safety of FTC and TAF (components of BIKTARVY) was evaluated in a single arm, open-label trial (Trial 1825) in virologically-suppressed adults with ESRD (estimated creatinine clearance of less than 15 mL/min) on chronic hemodialysis treated with FTC+TAF in combination with elvitegravir and cobicistat as a fixed-dose combination tablet for 96 weeks (N=55). The most commonly reported adverse reaction (adverse event assessed as causally related by investigator and all grades) was nausea (7%). Serious adverse events were reported in 65% of subjects and the most common serious adverse events were pneumonia (15%), fluid overload (7%), hyperkalemia (11%) and osteomyelitis (7%). Overall 7% of subjects permanently discontinued treatment due to an adverse event. In an extension phase of Trial 1825 in which 10 subjects switched to BIKTARVY for 48 weeks, the safety findings were similar to those in the initial phase of the open-label trial [see Use in Specific Populations (8.6), and Clinical Studies (14.3)].

Laboratory Abnormalities

The frequency of laboratory abnormalities (Grades 3–4) occurring in at least 2% of subjects receiving BIKTARVY in Trials 1489 and 1490 are presented in Table 2.

Changes in Serum Creatinine: BIC has been shown to increase serum creatinine due to inhibition of tubular secretion of creatinine without affecting renal glomerular function [see Clinical Pharmacology (12.2)]. Increases in serum creatinine occurred by Week 4 of treatment and remained stable through Week 144. In Trials 1489 and 1490, median (Q1, Q3) serum creatinine increased by 0.11 (0.03, 0.19) mg per dL from baseline to Week 144 in the BIKTARVY group and was similar to the comparator groups who received ABC/DTG/3TC, or DTG + FTC/TAF. There were no discontinuations due to renal adverse events and renal serious adverse events were encountered in less than 1% of participants treated with BIKTARVY through Week 144 in clinical trials.

Changes in Bilirubin: In Trials 1489 and 1490, total bilirubin increases were observed in 17% of subjects administered BIKTARVY through Week 144. Increases were primarily Grade 1 (1.0 to 1.5 × ULN) (12%) and Grade 2 (1.5 to 2.5 × ULN) (4%). Graded bilirubin increases in the ABC/DTG/3TC, and DTG + FTC/TAF groups, were 7% and 8%, respectively. Increases were primarily Grade 1 (5% ABC/DTG/3TC and 7% DTG + FTC/TAF) or Grade 2 (2% ABC/DTG/3TC and 2% DTG + FTC/TAF). There were no discontinuations due to hepatic adverse events through Week 144 in BIKTARVY clinical studies.

Clinical Trials in Pediatric Subjects

The safety of BIKTARVY was evaluated in HIV-1 infected virologically- suppressed subjects between the ages of 12 to less than 18 years and weighing at least 35 kg (N=50) through Week 48 (cohort 1), in virologically-suppressed subjects between the ages of 6 to less than 12 years and weighing at least 25 kg (N=50) through Week 24 (cohort 2), and in virologically suppressed subjects at least 2 years of age and weighing at least 14 to less than 25 kg (N=22) through Week 24 (cohort 3) in an open label clinical trial (Trial 1474) [see Clinical Studies (14.4)]. No new adverse reactions or laboratory abnormalities were identified compared to those observed in adults. Adverse reactions were reported in 11% of pediatric subjects. The majority (76%) of adverse reactions were Grade 1. No Grade 3 or 4 adverse reactions were reported. The adverse reaction reported by more than one subject (regardless of severity) was abdominal discomfort (n=2). One subject (1%) had Grade 2 adverse reactions of insomnia and anxiety that led to discontinuation of BIKTARVY. The other adverse reactions that occurred in single subjects were similar to those seen in adults.

6.2 Postmarketing Experience

The following events have been identified during post approval use of BIKTARVY or products containing TAF. Because these events are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Renal and Urinary Disorders

Acute renal failure, acute tubular necrosis, proximal renal tubulopathy, and Fanconi syndrome

Skin and Subcutaneous Tissue Disorders

Angioedema, Stevens-Johnson syndrome/toxic epidermal necrolysis, and urticaria

Investigations

Weight increased

CLINICAL STUDIES SECTION

14 CLINICAL STUDIES

14.1 Description of Clinical Trials

The efficacy and safety of BIKTARVY were evaluated in the trials summarized in Table 12.

End stage renal disease (estimated creatinine clearance of less than 15 mL/min by Cockcroft-Gault method).

Subjects received FTC+TAF in combination with elvitegravir and cobicistat for 96 weeks, followed by an extension phase in which 10 subjects received BIKTARVY for 48 weeks.

14.2 Clinical Trial Results in Adults with HIV-1 and No Antiretroviral

Treatment History

In Trial 1489, adults were randomized in a 1:1 ratio to receive either BIKTARVY (containing 50 mg of BIC, 200 mg of FTC, and 25 mg of TAF) (N=314) or ABC/DTG/3TC (600 mg/50 mg/300 mg) (N=315) once daily. In Trial 1490, subjects were randomized in a 1:1 ratio to receive either BIKTARVY (N=320) or DTG + FTC/TAF (50 mg + 200 mg/25 mg) (N=325) once daily.

In Trial 1489, the mean age was 34 years (range 18–71), 90% were male, 57% were White, 36% were Black, and 3% were Asian. 22% of patients identified as Hispanic/Latino. The mean baseline plasma HIV-1 RNA was 4.4 log10 copies/mL (range 1.3–6.5). The mean baseline CD4+ cell count was 464 cells per mm3 (range 0–1424) and 11% had CD4+ cell counts less than 200 cells per mm3. 16% of subjects had baseline viral loads greater than 100,000 copies per mL.

In Trial 1490, the mean age was 37 years (range 18–77), 88% were male, 59% were White, 31% were Black, and 3% were Asian. 25% of patients identified as Hispanic/Latino. The mean baseline plasma HIV-1 RNA was 4.4 log10 copies/mL (range 2.3–6.6). The mean baseline CD4+ cell count was 456 cells per mm3 (range 2–1636) and 12% had CD4+ cell counts less than 200 cells per mm3. 19% of subjects had baseline viral loads greater than 100,000 copies per mL.

In both trials, subjects were stratified by baseline HIV-1 RNA (less than or equal to 100,000 copies per mL, greater than 100,000 copies per mL to less than or equal to 400,000 copies per mL, or greater than 400,000 copies per mL), by CD4 count (less than 50 cells per mm3, 50–199 cells per mm3, or greater than or equal to 200 cells per mm3), and by region (US or ex-US).

Treatment outcomes of Trials 1489 and 1490 through Week 144 are presented in Table 13.

Treatment outcomes were similar across subgroups by age, sex, race, baseline viral load, and baseline CD4+ cell count.

In Trials 1489 and 1490, the mean increase from baseline in CD4+ count at Week 144 was 299 and 317 cells per mm3 in the BIKTARVY and ABC/DTG/3TC groups, respectively, and 278 and 289 cells per mm3 in the BIKTARVY and DTG + FTC/TAF groups, respectively.

14.3 Clinical Trial Results in Adults with Virologically-Suppressed HIV-1

Who Switched to BIKTARVY

In Trial 1844, the efficacy and safety of switching from a regimen of DTG + ABC/3TC or ABC/DTG/3TC to BIKTARVY were evaluated in a randomized, double- blind trial of virologically-suppressed (HIV-1 RNA less than 50 copies per mL) HIV-1 infected adults (N=563, randomized and dosed). Subjects must have been stably suppressed (HIV-1 RNA less than 50 copies per mL) on their baseline regimen for at least 3 months prior to trial entry and had no history of treatment failure. Subjects were randomized in a 1:1 ratio to either switch to BIKTARVY (containing 50 mg of BIC, 200 mg of FTC, and 25 mg of TAF) at baseline (N=282), or stay on their baseline antiretroviral regimen (N=281). Subjects had a mean age of 45 years (range 20–71), 89% were male, 73% were White, and 22% were Black. 17% of subjects identified as Hispanic/Latino. The mean baseline CD4+ cell count was 723 cells per mm3 (range 124–2444).

In Trial 1878, the efficacy and safety of switching from either ABC/3TC or FTC/TDF (200/300 mg) plus ATV or DRV (given with either cobicistat or ritonavir) to BIKTARVY (containing 50 mg of BIC, 200 mg of FTC, and 25 mg of TAF) were evaluated in a randomized, open-label study of virologically- suppressed HIV-1 infected adults (N=577, randomized and dosed). Subjects must have been stably suppressed on their baseline regimen for at least 6 months, must not have been previously treated with any INSTI, and had no history of treatment failure. Subjects were randomized in a 1:1 ratio to either switch to BIKTARVY (N=290) or stay on their baseline antiretroviral regimen (N=287). Subjects had a mean age of 46 years (range 20–79), 83% were male, 66% were White, and 26% were Black. 19% of subjects identified as Hispanic/Latino. The mean baseline CD4+ cell count was 663 cells per mm3 (range 62–2582). Subjects were stratified by prior treatment regimen. At screening, 15% of subjects were receiving ABC/3TC plus ATV or DRV (given with either cobicistat or ritonavir) and 85% of subjects were receiving FTC/TDF plus ATV or DRV (given with either cobicistat or ritonavir).

Treatment outcomes of Trials 1844 and 1878 through Week 48 are presented in Table 14.

In Trial 1844, treatment outcomes between treatment groups were similar across subgroups by age, sex, race, and region. The mean change from baseline in CD4+ count at Week 48 was -31 cells per mm3 in subjects who switched to BIKTARVY and 4 cells per mm3 in subjects who stayed on ABC/DTG/3TC.

In Trial 1878, treatment outcomes between treatment groups were similar across subgroups by age, sex, race, and region. The mean change from baseline in CD4+ count at Week 48 was 25 cells per mm3 in patients who switched to BIKTARVY and 0 cells per mm3 in patients who stayed on their baseline regimen.

In Trial 4030, the efficacy and safety of switching from DTG plus either FTC/TAF or FTC/TDF to BIKTARVY (containing 50 mg of BIC, 200 mg of FTC, and 25 mg of TAF) were evaluated in a randomized, double-blind study of virologically suppressed HIV-1 infected adults. Subjects must have been stably suppressed (HIV-1 RNA less than 50 copies/mL) on their baseline regimen for at least 6 months (if documented or suspected NRTI resistance), or at least 3 months (if no documented or suspected NRTI resistance) prior to trial entry. Subjects were randomized to switch to BIKTARVY (N=284) or to continue their prior treatment regimen, DTG+ F/TAF (N=281). The primary endpoint was the proportion of subjects with HIV-1 RNA ≥ 50 copies/mL at Week 48. At Week 48 the proportion of subjects with HIV-1 RNA ≥50 copies/mL was 0.4% (1/284) in the BIKTARVY group and 1.1% (3/281) in the DTG+F/TAF group (difference -0.7% [95%CI: -2.8%, 1.0%]).

Of the subjects receiving BIKTARVY, 47 had HIV-1 with pre-existing M184V or I resistance substitutions (M184M/V, M184M/I, M184V/I, M184V) in HIV-1 RT. Eighty-nine percent (42/47) of subjects with M184V or I remained suppressed (HIV-1 RNA < 50 copies/mL) and 11% (5/47 subjects) did not have virologic data at the Week 48 timepoint due to study drug discontinuation.

In Trial 1825, an open-label single arm trial, the efficacy, safety, and pharmacokinetics of FTC and TAF (components of BIKTARVY) were evaluated in virologically-suppressed adults with ESRD (estimated creatinine clearance of less than 15 mL/min) on chronic hemodialysis treated with FTC+TAF in combination with elvitegravir and cobicistat as a fixed-dose combination tablet for 96 weeks (N=55). In an extension phase of Trial 1825, 10 virologically-suppressed subjects switched to BIKTARVY and all subjects remained virologically suppressed (HIV-1 RNA < 50 copies/mL) for 48 weeks.

In Trial 4449, the efficacy and safety of switching from a stable antiretroviral regimen to BIKTARVY (containing 50 mg of BIC, 200 mg of FTC, and 25 mg of TAF) were evaluated in an open-label, single arm trial of virologically-suppressed (HIV-1 RNA less than 50 copies per mL) HIV-1 infected adults aged 65 years and over (N=86). Subjects treated with BIKTARVY had a mean age of 70 years (range: 65 to 80). The primary endpoint was the proportion of subjects with HIV RNA > 50 copies/mL at Week 48. No subjects had HIV RNA > 50 copies/mL. Ninety-one percent (78/86) of subjects remained suppressed (HIV-1 RNA < 50 copies/mL) at Week 48. Eight subjects did not have virologic data at the Week 48 timepoint due to discontinuation or missing data.

14.4 Clinical Trial Results in Pediatric Subjects with HIV-1

In Trial 1474, an open-label, single arm trial the efficacy, safety, and pharmacokinetics of BIKTARVY in HIV-1 infected pediatric subjects were evaluated in virologically-suppressed adolescents between the ages of 12 to less than 18 years weighing at least 35 kg (N=50), in virologically-suppressed children between the ages of 6 to less than 12 years weighing at least 25 kg (N=50), and in virologically-suppressed children at least 2 years of age and weighing at least 14 to less than 25 kg (N=22).

Cohort 1: Virologically-suppressed adolescents (12 to less than 18 years; at least 35 kg)

Subjects in cohort 1 treated with BIKTARVY (containing 50 mg of BIC, 200 mg of FTC, and 25 mg of TAF) once daily had a mean age of 14 years (range: 12 to 17) and a mean baseline weight of 51.7 kg (range: 35 to 123), 64% were female, 27% were Asian and 65% were black. At baseline, median CD4+ cell count was 750 cells per mm3 (range: 337 to 1207), and median CD4+% was 33% (range: 19% to 45%).

After switching to BIKTARVY, 98% (49/50) of subjects in cohort 1 remained suppressed (HIV-1 RNA < 50 copies/mL) at Week 48. The mean change from baseline in CD4+ cell count at Week 48 was -22 cells per mm3.

Cohort 2: Virologically-suppressed children (6 to less than 12 years; at least 25 kg)

Subjects in cohort 2 treated with BIKTARVY once daily had a mean age of 10 years (range: 6 to 11) and a mean baseline weight of 31.9 kg (range: 25 to 69), 54% were female, 22% were Asian and 72% were black. At baseline, median CD4+ cell count was 898 cells per mm3 (range 390 to 1991) and median CD4+% was 37% (range: 19% to 53%).

After switching to BIKTARVY (containing 50 mg of BIC, 200 mg of FTC, and 25 mg of TAF), 100% (50/50) of subjects in cohort 2 remained suppressed (HIV-1 RNA < 50 copies/mL) at Week 24. The mean change from baseline in CD4+ cell count at Week 24 was -24 cells per mm3.

Cohort 3: Virologically-suppressed children (at least 2 years; at least 14 to less than 25 kg)

Subjects in cohort 3 treated with BIKTARVY (containing 30 mg of BIC, 120 mg of FTC, and 15 mg of TAF) once daily had a mean age of 5 years (range: 3 to 9) and a mean baseline weight of 18.8 kg (range: 14 to 24), 50% were female, 23% were Asian and 73% were black. At baseline, the mean CD4+ cell count (SD) was 1104 (440), and the mean CD4% (SD) was 33.4% (6.0%).

After switching to BIKTARVY, 91% (20/22) of subjects in cohort 3 remained suppressed (HIV-1 RNA < 50 copies/mL) at Week 24. HIV-1 RNA was not collected at Week 24 for 2 subjects because of COVID-19 pandemic-related study disruption. The mean change from baseline to Week 24 in CD4+ cell count (SD) was −126 (264.2) cells per mm3 ; and the mean change in CD4% (SD) from baseline to Week 24 was 0.2% (4.4%).

OVERDOSAGE SECTION

10 OVERDOSAGE

No data are available on overdose of BIKTARVY in patients. If overdose occurs, monitor the patient for evidence of toxicity. Treatment of overdose with BIKTARVY consists of general supportive measures including monitoring of vital signs as well as observation of the clinical status of the patient.

Hemodialysis treatment removes approximately 30% of the FTC dose over a 3-hour dialysis period starting within 1.5 hours of FTC dosing (blood flow rate of 400 mL/min and a dialysate flow rate of 600 mL/min). It is not known whether FTC can be removed by peritoneal dialysis.

Tenofovir is efficiently removed by hemodialysis with an extraction coefficient of approximately 54%.

SPL PATIENT PACKAGE INSERT SECTION

SPL UNCLASSIFIED SECTION

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