EPCLUSA

Tablets EPCLUSA is a fixed-dose combination tablet containing sofosbuvir and velpatasvir for oral administration. Sofosbuvir is a nucleotide analog HCV NS5B polymerase inhibitor and velpatasvir is an NS5A inhibitor. Each 400 mg/100 mg tablet contains 400 mg sofosbuvir and 100 mg velpatasvir, and each 200 mg/50 mg tablet contains 200 mg sofosbuvir and 50 mg velpatasvir. The tablets include the following inactive ingredients: copovidone, croscarmellose sodium, magnesium stearate, and microcrystalline cellulose. The tablets are film-coated with a coating material containing the following inactive ingredients: iron oxide red, polyethylene glycol, polyvinyl alcohol, talc, and titanium dioxide. Pellets EPCLUSA oral pellets are for oral administration, supplied as small, white to off-white pellets in unit-dose packets. Each unit-dose of EPCLUSA oral pellets contains either 200 mg sofosbuvir and 50 mg velpatasvir or 150 mg sofosbuvir and 37.5 mg velpatasvir and the following inactive ingredients: colloidal silicon dioxide, copovidone, croscarmellose sodium, lactose monohydrate, magnesium stearate, and microcrystalline cellulose. The oral pellets are film-coated with a coating material containing the following inactive ingredients: amino methacrylate copolymer, colloidal silicon dioxide, hypromellose, L-tartaric acid, polyethylene glycol, stearic acid, talc, and titanium dioxide. Sofosbuvir: The IUPAC name for sofosbuvir is ( S )-isopropyl 2-(( S )-(((2 R ,3 R ,4 R ,5 R )-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2 H )-yl)-4-fluoro-3-hydroxy-4-methyltetrahydrofuran-2-yl)methoxy)-(phenoxy)phosphorylamino)propanoate. It has a molecular formula of C 22 H 29 FN 3 O 9 P and a molecular weight of 529.45. It has the following structural formula: Sofosbuvir is a white to off-white crystalline solid with a solubility of at least 2 mg/mL across the pH range of 2–7.7 at 37 °C and is slightly soluble in water. Velpatasvir: The IUPAC name for velpatasvir is methyl {(1 R )-2-[(2 S ,4 S )-2-(5-{2-[(2 S ,5 S )-1-{(2 S )-2-[(methoxycarbonyl)amino]-3-methylbutanoyl}-5-methylpyrrolidin-2-yl]-1,11-dihydro[2]benzopyrano[4',3':6,7]naphtho[1,2- d ]imidazol-9-yl}-1 H -imidazol-2-yl)-4-(methoxymethyl)pyrrolidin-1-yl]-2-oxo-1-phenylethyl}carbamate. It has a molecular formula of C 49 H 54 N 8 O 8 and a molecular weight of 883.0. It has the following structural formula: Velpatasvir is practically insoluble (less than 0.1 mg/mL) above pH 5, slightly soluble (3.6 mg/mL) at pH 2, and soluble (greater than 36 mg/mL) at pH 1.2. Chemical Structure Chemical Structure

EPCLUSA is indicated for the treatment of adults and pediatric patients 3 years of age and older with chronic hepatitis C virus (HCV) genotype 1, 2, 3, 4, 5, or 6 infection [see Dosage and Administration (2.2 , 2.3 , 2.4) and Clinical Studies (14) ] : without cirrhosis or with compensated cirrhosis with decompensated cirrhosis for use in combination with ribavirin. EPCLUSA is a fixed-dose combination of sofosbuvir, a hepatitis C virus (HCV) nucleotide analog NS5B polymerase inhibitor, and velpatasvir, an HCV NS5A inhibitor, and is indicated for the treatment of adults and pediatric patients 3 years of age and older with chronic HCV genotype 1, 2, 3, 4, 5, or 6 infection ( 1 ): without cirrhosis or with compensated cirrhosis with decompensated cirrhosis for use in combination with ribavirin.

Testing prior to the initiation of therapy: Test all patients for HBV infection by measuring HBsAg and anti-HBc. ( 2.1 ) See recommended treatment regimen and duration in patients 3 years of age and older with genotypes 1, 2, 3, 4, 5, or 6 HCV in table below: ( 2.2 ) Patient Population Regimen and Duration Treatment-naïve and treatment-experienced In clinical trials, regimens contained peginterferon alfa/ribavirin with or without an HCV NS3/4A protease inhibitor (boceprevir, simeprevir, or telaprevir). , without cirrhosis and with compensated cirrhosis (Child-Pugh A) EPCLUSA 12 weeks Treatment-naïve and treatment-experienced , with decompensated cirrhosis (Child-Pugh B and C) EPCLUSA + ribavirin 12 weeks Recommended dosage in adults: One tablet (400 mg of sofosbuvir and 100 mg of velpatasvir) taken orally once daily with or without food. ( 2.3 ) Recommended dosage in pediatric patients 3 years and older: Recommended dosage is based on weight. Refer to Table 2 of the full prescribing information for specific dosing guidelines based on body weight. ( 2.4 ) For pediatric patients less than 6 years of age, administer EPCLUSA oral pellets with food. ( 2.4 ) Instructions for Use should be followed for preparation and administration of EPCLUSA oral pellets. ( 2.5 ) HCV/HIV-1 coinfection: For patients with HCV/HIV-1 coinfection, follow the dosage recommendations in the table above. ( 2.2 ) For treatment-naïve and treatment-experienced liver transplant recipients without cirrhosis or with compensated cirrhosis (Child-Pugh A), the recommended regimen is EPCLUSA once daily for 12 weeks. ( 2.2 ) If used in combination with ribavirin, follow the recommendations for ribavirin dosing and dosage modifications. ( 2.3 , 2.4 ) For patients with renal impairment including end stage renal disease on dialysis, follow the dosage recommendations in the table above. ( 2.6 ) 2.1 Testing Prior to the Initiation of Therapy Test all patients for evidence of current or prior HBV infection by measuring hepatitis B surface antigen (HBsAg) and hepatitis B core antibody (anti-HBc) before initiating HCV treatment with EPCLUSA [see Warnings and Precautions (5.1) ]. 2.2 Recommended Treatment Regimen and Duration in Patients 3 Years of Age and Older Table 1 shows the recommended treatment regimen and duration based on patient population . For patients with HCV/HIV-1 coinfection follow the dosage recommendations in Table 1. For treatment-naïve and treatment-experienced liver transplant recipients without cirrhosis or with compensated cirrhosis (Child-Pugh A), the recommended regimen is EPCLUSA once daily for 12 weeks [see Clinical Studies (14.3 and 14.5) ]. Refer to Drug Interactions (7) for dosage recommendations for concomitant drugs. Table 1 Recommended Treatment Regimen and Duration in Patients 3 Years of Age and Older with Genotype 1, 2, 3, 4, 5, or 6 HCV Patient Population Treatment Regimen and Duration Treatment-naïve and treatment-experienced In clinical trials in adults, regimens contained peginterferon alfa/ribavirin with or without an HCV NS3/4A protease inhibitor (boceprevir, simeprevir, or telaprevir). , without cirrhosis and with compensated cirrhosis (Child-Pugh A) EPCLUSA 12 weeks Treatment-naïve and treatment-experienced , with decompensated cirrhosis (Child-Pugh B or C) EPCLUSA + ribavirin See Dosage and Administration 2.3 and 2.4 for ribavirin dosage recommendations . 12 weeks 2.3 Recommended Dosage in Adults The recommended dosage of EPCLUSA in adults is one tablet (400 mg sofosbuvir and 100 mg velpatasvir) taken orally once daily with or without food [see Clinical Pharmacology (12.3) ] . When administered with EPCLUSA, the recommended dosage of ribavirin is based on weight (administered with food): 1,000 mg per day for patients less than 75 kg and 1,200 mg for those weighing at least 75 kg, divided and administered twice daily. The starting dosage and on-treatment dosage of ribavirin can be decreased based on hemoglobin and creatinine clearance. For ribavirin dosage modifications refer to the ribavirin prescribing information [see Use in Specific Populations (8.6) and Clinical Studies (14.4) ]. 2.4 Recommended Dosage in Pediatric Patients 3 Years of Age and Older The recommended dosage of EPCLUSA in pediatric patients 3 years of age and older is based on weight and provided in Table 2. Table 3 provides the weight-based dosage of ribavirin when used in combination with EPCLUSA for pediatric patients. Take EPCLUSA oral pellets or tablets once daily with or without food. In pediatric patients less than 6 years of age, administer the oral pellets with food to increase tolerability related to palatability [see Use in Specific Populations (8.4) , Clinical Pharmacology (12.3) , and Clinical Studies (14.8) ] . Table 2 Dosing for Pediatric Patients 3 Years and Older with Genotype 1, 2, 3, 4, 5, or 6 HCV Using EPCLUSA Oral Pellets or Tablets Body Weight (kg) EPCLUSA Daily Dose Dosing of EPCLUSA Oral Pellets Dosing of EPCLUSA Tablet less than 17 150 mg/37.5 mg per day one 150 mg/37.5 mg packet of pellets once daily N/A 17 to less than 30 200 mg/50 mg per day one 200 mg/50 mg packet of pellets once daily one 200 mg/50 mg tablet once daily at least 30 400 mg/100 mg per day two 200 mg/50 mg packets of pellets once daily one 400 mg/100 mg tablet once daily Two 200 mg/50 mg tablets once daily can be used for patients who cannot swallow the 400 mg/100 mg tablet. Table 3 Recommended Dosing for Ribavirin in Combination Therapy with EPCLUSA for Pediatric Patients 3 Years and Older Body Weight (kg) Oral Ribavirin Daily Dosage The daily dosage of ribavirin is weight-based and is administered orally in two divided doses with food. less than 47 15 mg per kg per day (divided dose AM and PM) 47–49 600 mg per day (1 × 200 mg AM, 2 × 200 mg PM) 50–65 800 mg per day (2 × 200 mg AM, 2 × 200 mg PM) 66–80 1,000 mg per day (2 × 200 mg AM, 3 × 200 mg PM) greater than 80 1,200 mg per day (3 × 200 mg AM, 3 × 200 mg PM) 2.5 Preparation and Administration of Oral Pellets See the EPCLUSA oral pellets full Instructions for Use for details on the preparation and administration of EPCLUSA oral pellets. Do not chew EPCLUSA oral pellets to avoid a bitter aftertaste. EPCLUSA oral pellets can be taken directly in the mouth or with food (See Instructions for Use ). In pediatric patients less than 6 years of age, administer the oral pellets with food to increase tolerability related to palatability. Sprinkle the oral pellets on one or more spoonfuls of non-acidic soft food at or below room temperature. Examples of non-acidic foods include pudding, chocolate syrup, and ice cream. Take EPCLUSA oral pellets within 15 minutes of gently mixing with food and swallow the entire contents without chewing. 2.6 Renal Impairment No dosage adjustment of EPCLUSA is recommended in patients with any degree of renal impairment, including patients requiring dialysis. Administer EPCLUSA with or without ribavirin according to the recommendations in Table 1 [see Adverse Reactions (6.1) , Use in Specific Populations (8.6) , and Clinical Studies (14.6) ]. Refer to ribavirin tablet prescribing information for ribavirin dosage modification for patients with CrCl less than or equal to 50 mL per minute.

EPCLUSA and ribavirin combination regimen is contraindicated in patients for whom ribavirin is contraindicated. Refer to the ribavirin prescribing information for a list of contraindications for ribavirin [see Dosage and Administration (2.2 , 2.3 , 2.4) ]. EPCLUSA and ribavirin combination regimen is contraindicated in patients for whom ribavirin is contraindicated. ( 4 )

The following serious adverse reactions are described below and elsewhere in labeling: Serious Symptomatic Bradycardia When Coadministered with Amiodarone [see Warnings and Precautions (5.2) ]. The most common adverse reactions (incidence greater than or equal to 10%, all grades) observed in adults and pediatric subjects 6 years of age and older with treatment with EPCLUSA for 12 weeks are headache and fatigue. ( 6.1 ) The most common adverse reactions (incidence greater than or equal to 10%, grade 1 or 2) observed in pediatric subjects less than 6 years of age are vomiting and product use issue (spitting up the drug). ( 6.1 ) The most common adverse reactions (incidence greater than or equal to 10%, all grades) observed with treatment with EPCLUSA and ribavirin for 12 weeks in adult patients with decompensated cirrhosis are fatigue, anemia, nausea, headache, insomnia, and diarrhea. ( 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. 6.1 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. If EPCLUSA is administered with ribavirin, refer to the prescribing information for ribavirin for a description of ribavirin-associated adverse reactions. Clinical Trials in Adult Subjects Adverse Reactions in Subjects without Cirrhosis or with Compensated Cirrhosis The adverse reactions data for EPCLUSA in patients without cirrhosis or with compensated cirrhosis were derived from three Phase 3 clinical trials (ASTRAL-1, ASTRAL-2, and ASTRAL-3) which evaluated a total of 1035 subjects infected with genotype 1, 2, 3, 4, 5, or 6 HCV, without cirrhosis or with compensated cirrhosis, who received EPCLUSA for 12 weeks. EPCLUSA was studied in placebo- and active-controlled trials [see Clinical Studies (14.2) ] . The proportion of subjects who permanently discontinued treatment due to adverse events was 0.2% for subjects who received EPCLUSA for 12 weeks. The most common adverse reactions (adverse events assessed as causally related by the investigator and at least 10%) were headache and fatigue in subjects treated with EPCLUSA for 12 weeks. Adverse reactions, all grades, observed in greater than or equal to 5% of subjects receiving 12 weeks of treatment with EPCLUSA in ASTRAL-1 include headache (22%), fatigue (15%), nausea (9%), asthenia (5%), and insomnia (5%). Of subjects receiving EPCLUSA who experienced these adverse reactions, 79% had an adverse reaction of mild severity (Grade 1). With the exception of asthenia, each of these adverse reactions occurred at a similar frequency or more frequently in subjects treated with placebo compared to subjects treated with EPCLUSA (asthenia: 3% versus 5% for the placebo and EPCLUSA groups, respectively). The adverse reactions observed in subjects treated with EPCLUSA in ASTRAL-2 and ASTRAL-3 were consistent with those observed in ASTRAL-1. Irritability was also observed in greater than or equal to 5% of subjects treated with EPCLUSA in ASTRAL-3. Adverse Reactions in Subjects Coinfected with HCV and HIV-1 The safety assessment of EPCLUSA in subjects with HCV/HIV-1 coinfection was based on an open-label clinical trial (ASTRAL-5) in 106 subjects who were on stable antiretroviral therapy [see Clinical Studies (14.3) ] . The safety profile in HCV/HIV-1 coinfected subjects was similar to that observed in HCV mono-infected subjects. The most common adverse reactions occurring in at least 10% of subjects were fatigue (22%) and headache (10%). Adverse Reactions in Subjects with Decompensated Cirrhosis The safety assessment of EPCLUSA in subjects infected with genotype 1, 2, 3, 4, or 6 HCV with decompensated cirrhosis was based on one Phase 3 trial (ASTRAL-4) including 87 subjects who received EPCLUSA with ribavirin for 12 weeks. All 87 subjects had Child-Pugh B cirrhosis at screening. On the first day of treatment with EPCLUSA with ribavirin, 6 subjects and 4 subjects were assessed to have Child-Pugh A and Child-Pugh C cirrhosis, respectively [see Clinical Studies (14.4) ] . The most common adverse reactions (adverse events assessed as causally related by the investigator, all grades with frequency of 10% or greater) in the 87 subjects who received EPCLUSA with ribavirin for 12 weeks were fatigue (32%), anemia (26%), nausea (15%), headache (11%), insomnia (11%), and diarrhea (10%). Of subjects who experienced these adverse reactions, 98% had adverse reactions of mild to moderate severity. A total of 4 (5%) subjects permanently discontinued EPCLUSA with ribavirin due to an adverse event; there was no adverse event leading to discontinuation that occurred in more than 1 subject. Decreases in hemoglobin to less than 10 g/dL and 8.5 g/dL during treatment were observed in 23% and 7% of subjects treated with EPCLUSA with ribavirin for 12 weeks, respectively. Ribavirin was permanently discontinued in 17% of subjects treated with EPCLUSA with ribavirin for 12 weeks, due to adverse reactions. Less Common Adverse Reactions Reported in Clinical Trials The following adverse reactions occurred in less than 5% of subjects without cirrhosis or with compensated cirrhosis treated with EPCLUSA for 12 weeks and are included because of a potential causal relationship. Rash: In the ASTRAL-1 study, rash occurred in 2% of subjects treated with EPCLUSA and in 1% of subjects treated with placebo. No serious adverse reactions of rash occurred, and all rashes were mild or moderate in severity. Depression: In the ASTRAL-1 study, depressed mood occurred in 1% of subjects treated with EPCLUSA and was not reported by any subject taking placebo. No serious adverse reactions of depressed mood occurred, and all events were mild or moderate in severity. The following adverse reactions occurred in less than 10% of subjects with decompensated cirrhosis (ASTRAL-4) treated with EPCLUSA with ribavirin for 12 weeks and are included because of a potential causal relationship. Rash: Rash occurred in 5% of subjects treated with EPCLUSA with ribavirin. No serious adverse reactions of rash occurred, and all rashes were mild or moderate in severity. Laboratory Abnormalities Lipase Elevations: In ASTRAL-1, isolated, asymptomatic lipase elevations of greater than 3×ULN were observed in 3% and 1% of subjects treated with EPCLUSA and placebo for 12 weeks, respectively; and in 6% and 3% of subjects treated with EPCLUSA in ASTRAL-2 and ASTRAL-3, respectively. In the Phase 3 trial of subjects with decompensated cirrhosis (ASTRAL-4), lipase was assessed when amylase values were greater than or equal to 1.5×ULN. Isolated, asymptomatic lipase elevations of greater than 3×ULN were observed in 2% of subjects treated with EPCLUSA with ribavirin for 12 weeks. Creatine Kinase: In ASTRAL-1, isolated, asymptomatic creatine kinase elevations greater than or equal to 10×ULN were reported in 1% and 0% of subjects treated with EPCLUSA and placebo for 12 weeks, respectively; and in 2% and 1% of subjects treated with EPCLUSA in ASTRAL-2 and ASTRAL-3, respectively. In the Phase 3 trial with decompensated cirrhosis (ASTRAL-4), isolated, asymptomatic creatine kinase elevations greater than or equal to 10×ULN were reported in 1% of subjects treated with EPCLUSA with ribavirin for 12 weeks. Indirect Bilirubin: Increases in indirect bilirubin up to 3 mg/dL above baseline were noted among HIV-1/HCV coinfected subjects treated with EPCLUSA and an atazanavir/ritonavir-based antiretroviral regimen. The elevated indirect bilirubin values were not associated with clinical adverse events, and all subjects completed 12 weeks of EPCLUSA without dose adjustment or treatment interruption of either EPCLUSA or HIV antiretroviral agents. Adverse Reactions in Adult Liver Transplant Recipients The safety assessment of EPCLUSA in liver transplant recipients was based on an open-label clinical trial (Trial 2104) in 79 adults without cirrhosis or with compensated cirrhosis who received EPCLUSA for 12 weeks [see Clinical Studies (14.5) ] . One subject discontinued treatment due to an adverse event on Day 7. The adverse reactions observed were consistent with the known safety profile of EPCLUSA. Adverse reactions occurring in at least 5% of subjects were headache (18%), fatigue (15%), nausea (8%), diarrhea (6%), and asthenia (5%). Adverse Reactions in Adults with Severe Renal Impairment Requiring Dialysis In an open-label trial (Trial 4062), in which a total of 59 adults with HCV with compensated liver disease (with or without cirrhosis) and ESRD requiring dialysis received EPCLUSA for 12 weeks, the most common adverse reaction was nausea (7%) [see Clinical Studies (14.6) ]. Adverse Reactions in People Who Inject Drugs (PWID), Including Those on Medication-Assisted Treatment (MAT) for Opioid Use Disorder The safety of EPCLUSA in PWID is based on an open-label Phase 2 trial (SIMPLIFY) that enrolled 103 adult subjects with chronic HCV genotype 1, 2, 3, and 4 infection. Subjects who self-reported injection drug use within the 6 months prior to starting treatment were eligible and were treated with EPCLUSA for 12 weeks. The trial included a subset of 58 subjects on MAT for opioid use disorder. The adverse reactions observed from SIMPLIFY both overall and in subjects on MAT were consistent with the known safety profile of EPCLUSA. The most common adverse reactions overall were fatigue (18%), nausea (13%), and headache (11%) [see Use in Specific Populations (8.8) and Clinical Studies (14.7) ]. Adverse reactions leading to permanent discontinuation of treatment were not observed in any subjects. Adverse Reactions in Pediatric Subjects 3 Years of Age and Older The safety assessment of EPCLUSA in pediatric subjects 3 years of age and older is based on data from a Phase 2, open-label clinical trial (Study 1143) that enrolled 216 subjects who were treated with EPCLUSA for 12 weeks [see Clinical Studies (14.8) ] . The adverse reactions observed in pediatric subjects 6 years of age and older were consistent with those observed in clinical trials of EPCLUSA in adults. Among the 41 pediatric subjects less than 6 years of age, gastrointestinal adverse reactions were reported more commonly compared to subjects 6 years of age and older. Vomiting and product use issue (spitting up the drug) were reported in 15% and 10% of subjects, respectively; these adverse reactions were mild (Grade 1 or 2) and led to treatment discontinuation in 5 (12%) subjects [see Use in Specific Populations (8.4) and Clinical Studies (14.8) ] . 6.2 Postmarketing Experience The following adverse reactions have been identified during post approval use of sofosbuvir. Because postmarketing reactions 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. Cardiac Disorders Serious symptomatic bradycardia has been reported in patients taking amiodarone who initiate treatment with a sofosbuvir-containing regimen [see Warnings and Precautions (5.2) and Drug Interactions (7.3) ]. Skin and Subcutaneous Tissue Disorders Skin rashes, sometimes with blisters or angioedema-like swelling Angioedema

P-gp inducers and/or moderate to strong CYP inducers (e.g., rifampin, St. John's wort, carbamazepine): May decrease concentrations of sofosbuvir and/or velpatasvir. Use of EPCLUSA with P-gp inducers and/or moderate to strong CYP inducers is not recommended. ( 5.3 , 7 ) Consult the full prescribing information prior to use for potential drug interactions. ( 5.2 , 5.3 , 7 ) Clearance of HCV infection with direct acting antivirals may lead to changes in hepatic function, which may impact safe and effective use of concomitant medications. Frequent monitoring of relevant laboratory parameters (INR or blood glucose) and dose adjustments of certain concomitant medications may be necessary. ( 7.3 ) 7.1 Potential for Other Drugs to Affect EPCLUSA Sofosbuvir and velpatasvir are substrates of drug transporters P-gp and BCRP while GS-331007 (the predominant circulating metabolite of sofosbuvir) is not. In vitro, slow metabolic turnover of velpatasvir by CYP2B6, CYP2C8, and CYP3A4 was observed. Drugs that are inducers of P-gp and/or moderate to strong inducers of CYP2B6, CYP2C8, or CYP3A4 (e.g., rifampin, St. John's wort, carbamazepine) may decrease plasma concentrations of sofosbuvir and/or velpatasvir, leading to reduced therapeutic effect of EPCLUSA. The use of these agents with EPCLUSA is not recommended [see Warnings and Precautions (5.3) and Clinical Pharmacology (12.3) ] . EPCLUSA may be coadministered with P-gp, BCRP, and CYP inhibitors. 7.2 Potential for EPCLUSA to Affect Other Drugs Velpatasvir is an inhibitor of drug transporters P-gp, breast cancer resistance protein (BCRP), OATP1B1, OATP1B3, and OATP2B1. Coadministration of EPCLUSA with drugs that are substrates of these transporters may increase the exposure of such drugs. 7.3 Established and Potentially Significant Drug Interactions Clearance of HCV infection with direct acting antivirals may lead to changes in hepatic function, which may impact the safe and effective use of concomitant medications. For example, altered blood glucose control resulting in serious symptomatic hypoglycemia has been reported in diabetic patients in postmarketing case reports and published epidemiological studies. Management of hypoglycemia in these cases required either discontinuation or dose modification of concomitant medications used for diabetes treatment. Frequent monitoring of relevant laboratory parameters (e.g., International Normalized Ratio [INR] in patients taking warfarin, blood glucose levels in diabetic patients) or drug concentrations of concomitant medications such as cytochrome P450 substrates with a narrow therapeutic index (e.g., certain immunosuppressants) is recommended to ensure safe and effective use. Dose adjustments of concomitant medications may be necessary. Table 4 provides a listing of established or potentially clinically significant drug interactions. The drug interactions described are based on studies conducted with either EPCLUSA, the components of EPCLUSA (sofosbuvir and velpatasvir) as individual agents, or are predicted drug interactions that may occur with EPCLUSA [see Warnings and Precautions (5.2 , 5.3) and Clinical Pharmacology (12.3) ] . Table 4 Potentially Significant Drug Interactions: Alteration in Dose or Regimen May Be Recommended Based on Drug Interaction Studies or Predicted Interaction This table is not all inclusive. Concomitant Drug Class: Drug Name Effect on Concentration ↓ = decrease, ↑ = increase. Clinical Effect/Recommendation DF = disoproxil fumarate. Acid Reducing Agents: ↓ velpatasvir Velpatasvir solubility decreases as pH increases. Drugs that increase gastric pH are expected to decrease concentration of velpatasvir. Antacids (e.g., aluminum and magnesium hydroxide) Separate antacid and EPCLUSA administration by 4 hours. H 2 -receptor antagonists These interactions have been studied in healthy adults. (e.g., famotidine) H 2 -receptor antagonists may be administered simultaneously with or 12 hours apart from EPCLUSA at a dose that does not exceed doses comparable to famotidine 40 mg twice daily. Proton-pump inhibitors (e.g., omeprazole) Coadministration of omeprazole or other proton-pump inhibitors is not recommended. If it is considered medically necessary to coadminister, EPCLUSA should be administered with food and taken 4 hours before omeprazole 20 mg. Use with other proton-pump inhibitors has not been studied. Antiarrhythmics: amiodarone Effect on amiodarone, sofosbuvir, and velpatasvir concentrations unknown Coadministration of amiodarone with a sofosbuvir-containing regimen may result in serious symptomatic bradycardia. The mechanism of this effect is unknown. Coadministration of amiodarone with EPCLUSA is not recommended; if coadministration is required, cardiac monitoring is recommended [see Warnings and Precautions (5.2) and Adverse Reactions (6.2) ]. digoxin ↑ digoxin Therapeutic concentration monitoring of digoxin is recommended when coadministered with EPCLUSA. Refer to digoxin prescribing information for monitoring and dose modification recommendations for concentration increases of less than 50%. Anticancers: topotecan ↑ topotecan Coadministration is not recommended. Anticonvulsants: carbamazepine phenytoin phenobarbital ↓ sofosbuvir ↓ velpatasvir Coadministration is not recommended. Antimycobacterials: rifabutin rifampin rifapentine ↓ sofosbuvir ↓ velpatasvir Coadministration is not recommended. HIV Antiretrovirals: efavirenz ↓ velpatasvir Coadministration of EPCLUSA with efavirenz-containing regimens is not recommended. Regimens containing tenofovir DF ↑ tenofovir Monitor for tenofovir-associated adverse reactions in patients receiving EPCLUSA concomitantly with a regimen containing tenofovir DF. Refer to the prescribing information of the tenofovir DF-containing product for recommendations on renal monitoring. tipranavir/ritonavir ↓ sofosbuvir ↓ velpatasvir Coadministration is not recommended. Herbal Supplements: St. John's wort (Hypericum perforatum) ↓ sofosbuvir ↓ velpatasvir Coadministration is not recommended . HMG-CoA Reductase Inhibitors: rosuvastatin ↑ rosuvastatin Coadministration of EPCLUSA with rosuvastatin may significantly increase the concentration of rosuvastatin, which is associated with increased risk of myopathy, including rhabdomyolysis. Rosuvastatin may be administered with EPCLUSA at a dose that does not exceed 10 mg. atorvastatin ↑ atorvastatin Coadministration of EPCLUSA with atorvastatin may be associated with increased risk of myopathy, including rhabdomyolysis. Monitor closely for HMG-CoA reductase inhibitor-associated adverse reactions, such as myopathy and rhabdomyolysis . 7.4 Drugs without Clinically Significant Interactions with EPCLUSA Based on drug interaction studies conducted with the components of EPCLUSA (sofosbuvir or velpatasvir) or EPCLUSA, no clinically significant drug interactions have been observed or are expected with the following drugs [see Clinical Pharmacology (12.3) ]: EPCLUSA: atazanavir/ritonavir, buprenorphine/naloxone, cyclosporine, darunavir/ritonavir, dolutegravir, elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide, emtricitabine, methadone, naltrexone, raltegravir, or rilpivirine. Sofosbuvir: ethinyl estradiol/norgestimate, or tacrolimus. Velpatasvir: ethinyl estradiol/norgestimate, ketoconazole, or pravastatin. See Table 4 for use of EPCLUSA with certain HIV antiretroviral regimens [see Drug Interactions (7.3) ] .

Store below 30 °C (86 ºF). Dispense only in original container. Store below 30 °C (86 ºF). Do not use if carton tamper-evident seal or packet has been opened or damaged.