Sofosbuvir/Velpatasvir/Voxilaprevir Gilead 400 mg/100 mg/100 mg film-coated tablets (previously known as Vosevi)

Sofosbuvir/Velpatasvir/Voxilaprevir Gilead is indicated for the treatment of chronic hepatitis C virus (HCV) infection in patients aged 12 years and older and weighing at least 30 kg (see sections 4.2, 4.4 and 5.1).

Sofosbuvir/Velpatasvir/Voxilaprevir Gilead treatment should be initiated and monitored by a physician experienced in the management of patients with HCV infection.

Posology

The recommended dose of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead in patients aged 12 years and older and weighing at least 30 kg is one 400 mg/100 mg/100 mg tablet or two 200 mg/50 mg/50 mg tablets, taken orally, once daily with food (see section 5.2).

The recommended durations of treatment applicable to all HCV genotypes are shown in Table 1.

Table 1: Recommended treatment durations for Sofosbuvir/Velpatasvir/Voxilaprevir Gilead for all HCV genotypes in patients 12 years and older and weighing at least 30 kg

DAA: direct-acting antiviral agent

* In clinical studies the DAA experienced patients had been exposed to combination regimens containing any of the following: daclatasvir, dasabuvir, elbasvir, grazoprevir, ledipasvir, ombitasvir, paritaprevir, sofosbuvir, velpatasvir, voxilaprevir (administered with sofosbuvir and velpatasvir for less than 12 weeks).

Missed dose

If a dose of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead is missed and it is within 18 hours of the normal time, patients should be instructed to take the tablet(s) as soon as possible and then patients should take the next dose at the usual time. If it is after 18 hours then patients should be instructed to wait and take the next dose of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead at the usual time. Patients should be instructed not to take a double dose of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead.

Patients should be instructed that if vomiting occurs within 4 hours of dosing an additional dose of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead should be taken. If vomiting occurs more than 4 hours after dosing, no further dose of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead is needed (see section 5.1).

Elderly

No dose adjustment is warranted for elderly patients (see section 5.2).

Renal impairment

No dose adjustment of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead is required for patients with mild or moderate renal impairment.

Safety data are limited in patients with severe renal impairment (estimated Glomerular Filtration Rate [eGFR] < 30 mL/min/1.73 m²) and end stage renal disease (ESRD) requiring haemodialysis. Sofosbuvir/Velpatasvir/Voxilaprevir Gilead has not been studied in patients with ESRD requiring dialysis. Sofosbuvir/Velpatasvir/Voxilaprevir Gilead can be used in these patients with no dose adjustment when no other relevant treatment options are available (see section 4.4, 4.8, 5.1 and 5.2).

Hepatic impairment

No dose adjustment of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead is required for patients with mild hepatic impairment (Child-Pugh-Turcotte [CPT] Class A). Sofosbuvir/Velpatasvir/Voxilaprevir Gilead is not recommended in patients with moderate or severe hepatic impairment (CPT Class B or C) (see section 5.2).

Paediatric population

The safety and efficacy of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead in children aged less than 12 years and weighing less than 30 kg have not yet been established. No data are available.

Method of administration

For oral use.

Patients should be instructed to swallow the tablet(s) whole with food (see section 5.2). Due to the bitter taste, it is recommended that the film-coated tablet is not chewed or crushed.

Hypersensitivity to the active substances or to any of the excipients listed in section 6.1.

Concomitant use with medicinal products that are strong P-glycoprotein (P-gp) and/or strong cytochrome P450 (CYP) inducers (e.g. carbamazepine, phenobarbital, phenytoin, rifampicin, rifabutin and St. John's wort) (see section 4.5).

Concomitant use with rosuvastatin or dabigatran etexilate (see section 4.5).

Concomitant use with ethinylestradiol-containing medicinal products such as combined oral contraceptives or contraceptive vaginal rings or transdermal patches (see section 4.5).

Severe bradycardia and heart block

Life-threatening cases of severe bradycardia and heart block have been observed when sofosbuvir containing regimens are used in combination with amiodarone. Bradycardia has generally occurred within hours to days, but cases with a longer time to onset have been observed mostly up to 2 weeks after initiating HCV treatment.

Amiodarone should only be used in patients on Sofosbuvir/Velpatasvir/Voxilaprevir Gilead when other alternative anti- arrhythmic treatments are not tolerated or are contraindicated.

Should concomitant use of amiodarone be considered necessary, it is recommended that patients undergo cardiac monitoring in an in-patient setting for the first 48 hours of coadministration, after which outpatient or self-monitoring of the heart rate should occur on a daily basis through at least the first 2 weeks of treatment.

Due to the long half-life of amiodarone, cardiac monitoring as outlined above should also be carried out for patients who have discontinued amiodarone within the past few months and are to be initiated on Sofosbuvir/Velpatasvir/Voxilaprevir Gilead.

All patients with concurrent or recent use of amiodarone should be warned of the symptoms of bradycardia and heart block and should be advised to seek medical advice urgently should they experience them.

HCV/HBV co-infection

There are no data on the use of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead in patients with HCV/hepatitis B virus (HBV) co-infection. Cases of HBV reactivation, some of them fatal, have been reported during or after treatment with DAAs. HBV screening should be performed in all patients before initiation of treatment. HCV/HBV co-infected patients are at risk of HBV reactivation, and should therefore be monitored and managed according to current clinical guidelines.

Renal impairment

Safety data are limited in patients with severe renal impairment (estimated glomerular filtration rate [eGFR] < 30 mL/min/1.73 m²) and ESRD requiring haemodialysis.

Sofosbuvir/Velpatasvir/Voxilaprevir Gilead can be used in these patients with no dose adjustment when no other relevant treatment options are available (see sections 4.8, 5.1 and 5.2).

Hepatic impairment

No dose adjustment of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead is required for patients with mild hepatic impairment (CPT Class A). Sofosbuvir/Velpatasvir/Voxilaprevir Gilead is not recommended in patients with moderate or severe hepatic impairment (CPT Class B or C) (see section 5.2).

Liver transplant patients

The safety and efficacy of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead in the treatment of HCV infection in patients who are post-liver transplant have not been assessed. Treatment with Sofosbuvir/Velpatasvir/Voxilaprevir Gilead, in accordance with the recommended posology (see section 4.2), should be guided by an assessment of the potential benefits and risks for the individual patient.

Use with moderate P-gp inducers or moderate CYP inducers

Medicinal products that are moderate P-gp and/or moderate CYP inducers (e.g. efavirenz, modafinil, oxcarbazepine or rifapentine) may decrease sofosbuvir, velpatasvir and/or voxilaprevir plasma concentrations leading to reduced therapeutic effect of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead. Co-administration of such medicinal products with Sofosbuvir/Velpatasvir/Voxilaprevir Gilead is not recommended (see section 4.5).

Use with strong OATP1B inhibitors

Medicinal products that are strong OATP1B inhibitors (e.g. ciclosporin) may substantially increase voxilaprevir plasma concentrations, the safety of which has not been established. Co-administration of strong OATP1B inhibitors with Sofosbuvir/Velpatasvir/Voxilaprevir Gilead is not recommended (see section 4.5).

Use with certain HIV antiretroviral regimens

Sofosbuvir/Velpatasvir/Voxilaprevir Gilead has been shown to increase tenofovir exposure when used together with an HIV regimen containing tenofovir disoproxil fumarate and a pharmacokinetic enhancer (ritonavir or cobicistat). The safety of tenofovir disoproxil fumarate in the setting of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead and a pharmacokinetic enhancer has not been established. The potential risks and benefits associated with co-administration of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead with the fixed-dose combination tablet containing elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate or tenofovir disoproxil fumarate given in conjunction with a boosted HIV protease inhibitor (e.g. darunavir) should be considered, particularly in patients at increased risk of renal dysfunction. Patients receiving Sofosbuvir/Velpatasvir/Voxilaprevir Gilead concomitantly with elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate or with tenofovir disoproxil fumarate and a boosted HIV protease inhibitor should be monitored for tenofovir-associated adverse reactions. Refer to tenofovir disoproxil fumarate, emtricitabine/tenofovir disoproxil fumarate, or elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate Summary of Product Characteristics for recommendations on renal monitoring.

Use in diabetic patients

Diabetics may experience improved glucose control, potentially resulting in symptomatic hypoglycaemia, after initiating HCV DAA treatment. Glucose levels of diabetic patients initiating DAA therapy should be closely monitored, particularly within the first 3 months, and their diabetic treatment modified when necessary. The physician in charge of the diabetic care of the patient should be informed when DAA therapy is initiated.

Excipients

Patients with rare hereditary problems of galactose intolerance, total lactase deficiency or glucose-galactose malabsorption should not take this medicinal product.

This medicinal product contains less than 1 mmol sodium (23 mg) per tablet, that is to say essentially 'sodium‑free'.

As Sofosbuvir/Velpatasvir/Voxilaprevir Gilead contains sofosbuvir, velpatasvir and voxilaprevir, any interactions that have been identified with these active substances individually may occur with Sofosbuvir/Velpatasvir/Voxilaprevir Gilead.

Pharmacokinetic interactions

Potential for Sofosbuvir/Velpatasvir/Voxilaprevir Gilead to affect other medicinal products

Velpatasvir and voxilaprevir are inhibitors of drug transporters P-gp, breast cancer resistance protein (BCRP), organic anion-transporting polypeptide (OATP) 1B1 and OATP1B3. Co-administration of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead with medicinal products that are substrates of these transporters may increase the exposure of such medicinal products.

Medicinal products that are sensitive substrates of these transporters and for which elevated plasma levels are associated with serious events are contraindicated (see Table 2). Dabigatran etexilate (P-gp substrate) and rosuvastatin (OATP1B and BCRP substrate) are contraindicated (see section 4.3 and Table 2).

Potential for other medicinal products to affect Sofosbuvir/Velpatasvir/Voxilaprevir Gilead

Sofosbuvir, velpatasvir and voxilaprevir are substrates of drug transporters P-gp and BCRP. Velpatasvir and voxilaprevir are substrates of drug transporters OATP1B1 and OATP1B3. In vitro, slow metabolic turnover of velpatasvir primarily by CYP2B6, CYP2C8 and CYP3A4 and of voxilaprevir primarily by CYP3A4 was observed.

Medicinal products that may decrease plasma exposure of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead

Medicinal products that are strong inducers of P-gp and/or strong inducers of CYP2B6, CYP2C8, or CYP3A4 (e.g. carbamazepine, phenobarbital, phenytoin, rifampicin, rifabutin and St. John's wort) may decrease plasma concentrations of sofosbuvir, velpatasvir and/or voxilaprevir leading to reduced therapeutic effect of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead. The use of such medicinal products with Sofosbuvir/Velpatasvir/Voxilaprevir Gilead is contraindicated (see section 4.3 and Table 2).

Medicinal products that are moderate P-gp inducers and/or moderate CYP inducers (e.g. efavirenz, modafinil, oxcarbazepine or rifapentine) may decrease sofosbuvir, velpatasvir and/or voxilaprevir plasma concentrations leading to reduced therapeutic effect of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead. Co-administration with such medicinal products is not recommended with Sofosbuvir/Velpatasvir/Voxilaprevir Gilead (see section 4.4 and Table 2).

Medicinal products that may increase plasma exposure of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead

Co-administration with medicinal products that inhibit P-gp or BCRP may increase sofosbuvir, velpatasvir or voxilaprevir plasma concentrations. Medicinal products that inhibit OATP1B, CYP2B6, CYP2C8, or CYP3A4 may increase plasma concentrations of velpatasvir or voxilaprevir. The use of strong inhibitors of OATP1B (e.g. ciclosporin) with Sofosbuvir/Velpatasvir/Voxilaprevir Gilead is not recommended (see section 4.4 and Table 2). Clinically significant medicinal product interactions with Sofosbuvir/Velpatasvir/Voxilaprevir Gilead mediated by P-gp, BCRP and CYP inhibitors are not expected. Sofosbuvir/Velpatasvir/Voxilaprevir Gilead may be co-administered with P-gp, BCRP and CYP inhibitors.

Pharmacodynamic interactions

Patients treated with vitamin K antagonists

As liver function may change during treatment with Sofosbuvir/Velpatasvir/Voxilaprevir Gilead, close monitoring of International Normalised Ratio (INR) values is recommended.

Impact of DAA therapy on medicinal products metabolized by the liver

The pharmacokinetics of medicinal products that are metabolized by the liver (e.g. immunosuppressive agents such as calcineurin inhibitors) may be impacted by changes in liver function during DAA therapy, related to clearance of HCV.

Patients treated with ethinylestradiol-containing medicinal products

Concomitant use with ethinylestradiol-containing medicinal products may increase the risk of alanine aminotransferase (ALT) elevations and is contraindicated (see section 4.3 and Table 2).

Interactions between Sofosbuvir/Velpatasvir/Voxilaprevir Gilead and other medicinal products

Table 2 provides a listing of established or potentially clinically significant medicinal product interactions (where 90% confidence interval [CI] of the geometric least-squares mean [GLSM] ratio were within “↔”, extended above “↑”, or extended below “↓” the predetermined interaction boundaries). The medicinal product interactions described are based on studies conducted with either sofosbuvir/velpatasvir/voxilaprevir, its components (sofosbuvir, velpatasvir, and/or voxilaprevir), or are predicted medicinal product interactions that may occur with Sofosbuvir/Velpatasvir/Voxilaprevir Gilead. The table is not all-inclusive.

Table 2: Interactions between Sofosbuvir/Velpatasvir/Voxilaprevir Gilead and other medicinal products

a. Mean ratio (90% CI) of co-administered drug pharmacokinetics of study medicinal products alone or in combination. No effect = 1.00.

b. All interaction studies conducted in healthy volunteers.

c. Lack of pharmacokinetics interaction lower bound 70%.

d. These are medicinal products within class where similar interactions could be predicted.

e. Bioequivalence/Equivalence boundary 80-125%.

f. Lack of pharmacokinetics interaction bounds 70-143%.

g. Administered as efavirenz, emtricitabine and tenofovir DF fixed-dose combination.

h. Administered as sofosbuvir, velpatasvir fixed-dose combination.

i. Administered as emtricitabine, rilpivirine, and tenofovir alafenamide fixed-dose combination.

j. Administered as emtricitabine, tenofovir disoproxil fumarate fixed-dose combination.

k. Lack of pharmacokinetics interaction bounds 50-200%.

l. Administered as elvitegravir, cobicistat, emtricitabine and tenofovir alafenamide fixed-dose combination.

Pregnancy

There are no or limited amount of data (less than 300 pregnancy outcomes) from the use of sofosbuvir, velpatasvir, voxilaprevir or Sofosbuvir/Velpatasvir/Voxilaprevir Gilead in pregnant women.

Sofosbuvir

Animal studies do not indicate direct or indirect harmful effects with respect to reproductive toxicity (see section 5.3).

It has not been possible to fully estimate exposure margins achieved for sofosbuvir in the rat relative to the exposure in humans at the recommended clinical dose (see section 5.3).

Velpatasvir

Animal studies have shown a possible link to reproductive toxicity (see section 5.3).

Voxilaprevir

Animal studies do not indicate direct or indirect harmful effects with respect to reproductive toxicity (see section 5.3).

As a precautionary measure, Sofosbuvir/Velpatasvir/Voxilaprevir Gilead use is not recommended during pregnancy.

Breast-feeding

It is unknown whether sofosbuvir, metabolites of sofosbuvir, velpatasvir or voxilaprevir are excreted in human milk.

Available pharmacokinetic data in animals have shown excretion of velpatasvir and metabolites of sofosbuvir in milk. When administered to lactating rats, voxilaprevir was detected in the plasma of nursing pups.

A risk to the newborns/infants cannot be excluded. Therefore, Sofosbuvir/Velpatasvir/Voxilaprevir Gilead should not be used during breast-feeding.

Fertility

No human data on the effect of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead on fertility are available. Animal studies do not indicate harmful effects of sofosbuvir, velpatasvir or voxilaprevir on fertility.

Sofosbuvir/Velpatasvir/Voxilaprevir Gilead has no or negligible influence on the ability to drive and use machines.

Summary of the safety profile

In Phase 2 and 3 clinical studies, the proportion of patients who permanently discontinued treatment due to adverse reactions was 0.1% for patients receiving sofosbuvir/velpatasvir/voxilaprevir for 8 weeks. There were no patients receiving sofosbuvir/velpatasvir/voxilaprevir for 12 weeks who permanently discontinued treatment due to adverse reactions in the Phase 2 and 3 pivotal clinical studies.

Tabulated summary of adverse reactions

Assessment of adverse reactions for Sofosbuvir/Velpatasvir/Voxilaprevir Gilead is based on safety data from clinical studies and post-marketing experience. All adverse reactions are presented in Table 3. The adverse reactions are listed below by system organ class and frequency.

Frequencies are defined as follows: very common (≥ 1/10); common (≥ 1/100 to < 1/10); uncommon (≥ 1/1000 to < 1/100); rare (≥ 1/10,000 to < 1/1000) or very rare (< 1/10,000).

Table 3: Adverse reactions identified with Sofosbuvir/Velpatasvir/Voxilaprevir Gilead

a. Adverse reaction identified through post-marketing surveillance for sofosbuvir/velpatasvir-containing products

Description of selected adverse reactions

Cardiac arrhythmias

Cases of severe bradycardia and heart block have been observed when sofosbuvir containing regimens are used in combination with amiodarone and/or other medicinal products that lower heart rate (see sections 4.4 and 4.5).

Skin disorders

Frequency not known: Stevens-Johnson syndrome

Laboratory abnormalities

Total bilirubin

In the Phase 3 studies increases in total bilirubin less than or equal to 1.5 x the upper limit of normal were observed in 4% of patients without cirrhosis and 10% of patients with compensated cirrhosis, due to inhibition of OATP1B1 and OATP1B3 by voxilaprevir. Total bilirubin levels decreased after completing Sofosbuvir/Velpatasvir/Voxilaprevir Gilead treatment.

Patients with renal impairment

The safety of sofosbuvir in a fixed dose combination with either ledipasvir or velpatasvir has been studied in 154 patients with ESRD requiring dialysis (Study 4062 and Study 4063). In this setting, exposure of sofosbuvir metabolite GS-331007 is 20- fold increased, exceeding levels where adverse reactions have been observed in preclinical studies. In this limited clinical safety data set, the rate of adverse events and deaths was not clearly elevated from what is expected in ESRD patients.

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme, Website: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.

Paediatric population

The safety assessment of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead in paediatric patients aged 12 years and older is based on data from 21 DAA-naïve patients with genotype 1, 2, 3, or 4 HCV infection (without cirrhosis) who were treated with Sofosbuvir/Velpatasvir/Voxilaprevir Gilead for 8 weeks in a Phase 2, open-label clinical study (study 1175). The adverse reactions observed were consistent with those observed in clinical studies of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead in adults.

The highest documented doses of sofosbuvir, velpatasvir and voxilaprevir were single doses of 1,200 mg, 500 mg, and 900 mg, respectively. In healthy adult volunteer studies with sofosbuvir and velpatasvir, there were no untoward effects observed at these dose levels, and adverse events were similar in frequency and severity to those reported in the placebo groups. The most common adverse reactions in patients receiving voxilaprevir 900 mg were diarrhoea (34%), nausea (17%) and headache (9%).

No specific antidote is available for overdose with Sofosbuvir/Velpatasvir/Voxilaprevir Gilead. If overdose occurs the patient must be monitored for evidence of toxicity. Treatment of overdose with Sofosbuvir/Velpatasvir/Voxilaprevir Gilead consists of general supportive measures including monitoring of vital signs, as well as observation of the clinical status of the patient. Haemodialysis can efficiently remove the predominant circulating metabolite of sofosbuvir, GS-331007, with an extraction ratio of 53%. Haemodialysis is unlikely to result in significant removal of velpatasvir or voxilaprevir since velpatasvir and voxilaprevir are highly bound to plasma proteins.

Pharmacotherapeutic group: Antivirals for systemic use; Direct-acting antivirals, ATC code: J05AP56

Mechanism of action

Sofosbuvir is a pan-genotypic inhibitor of the HCV NS5B RNA-dependent RNA polymerase, which is required for viral replication. Sofosbuvir is a nucleotide prodrug that undergoes intracellular metabolism to form the pharmacologically active uridine analogue triphosphate (GS-461203), which can be incorporated into HCV RNA by the NS5B polymerase and acts as a chain terminator. In a biochemical assay, GS-461203 inhibited the polymerase activity of the recombinant NS5B from HCV genotype 1b, 2a, 3a, and 4a. GS-461203 is neither an inhibitor of human DNA and RNA polymerases nor an inhibitor of mitochondrial RNA polymerase.

Velpatasvir is a pan-genotypic HCV inhibitor targeting the HCV NS5A protein, which is required for viral replication.

Voxilaprevir is a pan-genotypic inhibitor of the HCV NS3/4A protease. Voxilaprevir acts as a noncovalent, reversible inhibitor of the NS3/4A protease.

Antiviral activity

The 50% effective concentration (EC₅₀) values of sofosbuvir, velpatasvir and voxilaprevir against full-length or chimeric replicons encoding NS5B, NS5A and NS3 protease sequences from the laboratory strains are presented in Table 4. The EC₅₀ values of sofosbuvir, velpatasvir and voxilaprevir against clinical isolates are presented in Table 5.

Table 4: Activity of sofosbuvir, velpatasvir and voxilaprevir against full-length or chimeric laboratory replicons

NA: Not available

a. Mean value from multiple experiments of same laboratory replicon.

b. Stable chimeric 1b replicons carrying NS5B genes from genotype 2b, 5a or 6a were used for testing.

c. Data from various strains of full length NS5A replicons or chimeric NS5A replicons carrying full-length NS5A genes that contain L31 or M31 polymorphisms.

d. Data from a chimeric NS5A replicon carrying NS5A amino acids 9-184.

e. Stable cell lines expressing Renilla luciferase-encoding replicons.

f. Data obtained from transiently transfected replicons.

Table 5: Activity of sofosbuvir, velpatasvir and voxilaprevir against transient replicons containing NS5A, NS5B or NS3 protease from clinical isolates

NA: Not available

The presence of 40% human serum had no effect on the anti-HCV activity of sofosbuvir but reduced the anti-HCV activity of velpatasvir and voxilaprevir by 13- and 6.8-fold, respectively, against genotype 1a HCV replicons.

Resistance

In cell culture

For sofosbuvir, the NS5B substitution S282T was selected in genotype 1-6 replicons and was associated with 2- to 18-fold reduced susceptibility to sofosbuvir.

For velpatasvir in genotype 1-6 replicons, resistance-associated substitutions selected in 2 or more genotypes were L31I/V and Y93H. Site directed mutagenesis of NS5A resistance associated variants (RAVs) showed that substitutions conferring a > 100- fold reduction in velpatasvir susceptibility are M28G, A92K and Y93H/N/R/W in genotype 1a, A92K in genotype 1b, C92T and Y93H/N in genotype 2b, Y93H in genotype 3, and L31V and P32A/L/Q/R in genotype 6. No individual RAV tested in genotypes 2a, 4a or 5a conferred a > 100-fold reduction in velpatasvir susceptibility.

For voxilaprevir in genotype 1-6 replicons, resistance-associated substitutions selected in 2 or more genotypes were Q41H, A156V/T/L and D168E/H/Y. Site directed mutagenesis of known NS3 RAVs showed that substitutions conferring a > 100-fold reduction in voxilaprevir susceptibility are A156V, A156T or A156L in genotype 1a, 1b, 2a, 3a and 4. No individual RAV tested in genotypes 2b, 5a or 6a conferred a > 100-fold reduction in voxilaprevir susceptibility.

For both velpatasvir and voxilaprevir, combinations of RAVs often showed greater reductions in susceptibility than individual RAVs alone.

Cross resistance in cell culture

Voxilaprevir is active in vitro against most of the NS3 RAVs that confer resistance to first generation NS3/4A protease inhibitors. Additionally, velpatasvir is active in vitro against most of the NS5A RAVs that confer resistance to ledipasvir and daclatasvir. Sofosbuvir, velpatasvir, and voxilaprevir were fully active against substitutions associated with resistance to other classes of DAAs with different mechanisms of actions, e.g. voxilaprevir was fully active against NS5A and NS5B NI RAVs.

In clinical studies

Studies in DAA-experienced adult-patients

Of the 263 NS5A inhibitor-experienced patients treated with sofosbuvir/velpatasvir/voxilaprevir for 12 weeks in POLARIS-1 (see Table 10), 7 of 263 (3%) patients (2 with genotype 1, 4 with genotype 3, and 1 with genotype 4) did not achieve sustained virologic response (SVR12) and qualified for resistance analysis; 6 relapsed and 1 experienced virologic breakthrough with pharmacokinetic data consistent with nonadherence. The patient with genotype 1a and virologic breakthrough developed the NS5A RAVs L31M and Y93H. One patient with genotype 4d who relapsed developed the NS5A RAV Y93H. No NS3, NS5A, or NS5B nucleoside inhibitor (NI) RAVs emerged in the other 5 patients who relapsed.

Of the 182 DAA-experienced patients treated with sofosbuvir/velpatasvir/voxilaprevir for 12 weeks in POLARIS-4 (see Table 11), 1 of 182 (1%) patients relapsed and qualified for resistance analysis. No NS3, NS5A, or NS5B NI RAVs emerged in this patient infected with genotype 1a HCV.

Studies in DAA-naïve adult-patients

In the POLARIS-2 sofosbuvir/velpatasvir/voxilaprevir 8-week treatment group (see Table 12), a total of 21 of 501 (4%) patients (16 with genotype 1, 2 with genotype 2, 2 with genotype 4, and 1 with genotype 5) qualified for resistance analysis due to relapse. Of these 21 patients, 1 patient had virus with emergent NS5A RAVs Q30R and L31M at failure. No NS3 and NS5B NI RAVs emerged in any of these 21 patients at failure. In the sofosbuvir/velpatasvir 12-week treatment group, a total of 3 of 440 (1%) patients (2 with genotype 1, 1 with genotype 4) qualified for resistance analysis due to relapse. Of these 3 patients, 1 patient (33%) had virus with emergent NS5A RAV Y93N at failure. No NS3 and NS5B NI RAVs emerged in any of these 3 patients.

In the POLARIS-3 sofosbuvir/velpatasvir/voxilaprevir 8-week treatment group (see Table 14), 2 of 110 (2%) patients (genotype 3) qualified for resistance analysis due to relapse. No NS3, NS5A, or NS5B NI RAVs emerged in either of these patients. In the sofosbuvir/velpatasvir 12-week treatment group, 2 of 109 (2%) patients qualified for resistance analysis due to virologic failure. Both of these patients had virus with emergent NS5A RAV Y93H at failure. No NS3 or NS5B NI RAVs emerged in either of these patients.

Effect of baseline HCV resistance-associated variants on treatment outcome

Studies in DAA-experienced adult-patients

Analyses were conducted to explore the association between pre-existing baseline NS3 and NS5A RAVs and treatment outcome for patients that had previously been treated with DAA regimens and received sofosbuvir/velpatasvir/voxilaprevir for 12 weeks in POLARIS-1 and POLARIS-4. These are shown in Table 6.

Table 6: SVR12 in DAA-experienced patients with or without baseline NS3 or NS5A RAVs by study

a. Patients with NS3 and/or NS5A gene sequencing failure.

SVR12 was achieved in 18 of 19 (95%) patients who had baseline NS5B NI RAVs in POLARIS-1, including 2 patients who had virus with the S282T NS5B NI RAV in addition to NS5A RAVs at baseline. In POLARIS-4, a total of 14 patients had virus with NS5B NI RAVs at baseline and all achieved SVR12.

Studies in DAA-naïve adult-patients

Analyses were conducted to explore the association between pre-existing baseline NS3 and NS5A RAVs and treatment outcome for patients that had not previously been treated with DAA regimens and received sofosbuvir/velpatasvir/voxilaprevir for 8 weeks in POLARIS-2 and POLARIS-3. These are shown in Table 7.

Table 7: SVR12 in DAA-naïve patients with or without baseline NS3 or NS5A RAVs by study

a. Patients with NS3 and/or NS5A gene sequencing failure.

SVR12 was achieved in all 39 patients who had baseline NS5B NI RAVs in POLARIS-2 and 2 of 3 (67%) patients in POLARIS-3. The NS5B NI RAV S282T was not detected in any patient in POLARIS-2 and POLARIS-3 studies. Among patients with genotype 1a in POLARIS-2, SVR12 was 87% (53/61) for those with Q80K/L/R RAVs and 94% (99/105) for those without Q80K/L/R RAVs.

Study in paediatric patients

Baseline NS3, NS5A, and NS5B sequences were obtained for 21 paediatric patients aged 12 years to less than 18 years who had not previously been treated with DAA regimens in a Phase 2 study. Of the 21 patients, baseline NS3, NS5A and/or NS5B NI RAVs were detected in 1, 10, and 3 patients, respectively. Following treatment with Sofosbuvir/Velpatasvir/Voxilaprevir Gilead for 8 weeks, SVR12 was achieved in all 21 patients, including all patients who had baseline NS3, NS5A, and/or NS5B NI RAVs.

Clinical efficacy

The efficacy of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead (sofosbuvir [SOF]/velpatasvir [VEL]/voxilaprevir [VOX]) was evaluated in four Phase 3 studies in adults, two studies in DAA-experienced patients and two studies in DAA-naïve patients with, genotype 1 to 6 HCV infection without cirrhosis or with compensated cirrhosis, as summarised in Table 8.

Demographics and baseline characteristics for all studies are detailed in Table 9.

Table 8: Studies conducted with Sofosbuvir/Velpatasvir/Voxilaprevir Gilead

DAA: direct-acting antiviral; GT: genotype; SOF: sofosbuvir; VEL: velpatasvir; VOX: voxilaprevir

Table 9: Demographics and baseline characteristics for patients enrolled into POLARIS-1, -2, -3 and -4

Serum HCV RNA values were measured during the clinical studies using the COBAS AmpliPrep/COBAS Taqman HCV test (version 2.0) with a lower limit of quantification (LLOQ) of 15 IU per mL. Sustained virologic response (SVR12), defined as HCV RNA less than LLOQ at 12 weeks after the cessation of treatment, was the primary endpoint to determine the HCV cure rate.

Clinical studies in DAA-experienced patients

NS5A inhibitor-experienced adults (POLARIS-1)

Table 10 presents the SVR12 by HCV genotype for the POLARIS-1 trial. The median time between prior DAA failure and first dose of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead for patients enrolled into POLARIS-1 was 39 weeks (range: 11 to 299 weeks). No patients in the placebo group achieved SVR4.

Table 10: SVR12 in NS5A-inhibitor experienced patients by HCV genotype in study POLARIS-1*

GT = genotype

* The most common prior NS5A inhibitors were ledipasvir (LDV) (51%), daclatasvir (27%), and ombitasvir (11%).

a. One patient with undetermined genotype achieved SVR12.

b. Four patients had genotype 1 subtypes other than genotype 1a or genotype 1b; all 4 patients achieved SVR12.

c. Pharmacokinetic data for the 1 patient with on-treatment virologic failure was consistent with non-adherence.

d. The denominator for relapse is the number of patients with HCV RNA < LLOQ at their last on-treatment assessment.

e. Other includes patients with missing data and those who discontinued treatment prior to virologic suppression.

DAA-experienced adults who had not received an NS5A inhibitor (POLARIS-4)

Table 11 presents the SVR12 by HCV genotype and virologic outcome for the POLARIS-4 study. The median time between prior DAA failure and first dose of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead or sofosbuvir/velpatasvir for patients enrolled into POLARIS-4 was 76 weeks (range: 10 to 549 weeks).

Table 11: SVR12 by HCV genotype and virologic outcome in study POLARIS-4

a. The majority (85%) of patients previously failed a regimen containing sofosbuvir.

b. The denominator for relapse is the number of patients with HCV RNA < LLOQ at their last on-treatment assessment.

c. Other includes patients with missing data and those who discontinued treatment prior to virologic suppression.

Clinical studies in DAA-naïve patients

DAA-naïve adults with genotype 1, 2, 3, 4, 5, or 6 HCV infection (POLARIS-2)

Table 12 presents the SVR12 by HCV genotype and virologic outcome for the POLARIS-2 study.

Table 12: SVR12 by HCV genotype and virologic outcome in study POLARIS-2*

* 23% of patients enrolled into POLARIS-2 had received prior treatment with an interferon-based regimen.

a. Two patients with undetermined genotype in the SOF/VEL/VOX group achieved SVR12.

b. Two patients had genotype 1 subtypes other than genotype 1a or genotype 1b; both patients achieved SVR12.

c. The denominator for relapse is the number of patients with HCV RNA <LLOQ at their last on-treatment assessment.

d. Other includes patients with missing data and those who discontinued treatment prior to virologic suppression.

Treatment with Sofosbuvir/Velpatasvir/Voxilaprevir Gilead for 8 weeks in POLARIS-2 did not demonstrate noninferiority to treatment with sofosbuvir/velpatasvir for 12 weeks with a prespecified margin of -5%. The difference in SVR12 was driven by a lower response rate in patients with genotype 1a infection and/or cirrhosis. In patients with genotype 1a without cirrhosis treated with Sofosbuvir/Velpatasvir/Voxilaprevir Gilead for 8 weeks, outcome was influenced by the following baseline factors: Body Max Index BMI ≥ 30 kg/m², Q80K/L/R RAVs, IL28B non-CC, HCV RNA ≥ 800,000 IU/mL. The SVR12 was 98% among those with two or fewer factors and 81% among those with three or four factors. Table 13 presents the SVR12 by HCV genotype by cirrhosis status for the POLARIS-2 study.

Table 13: SVR12 by HCV genotype and virologic outcome in patients who received Sofosbuvir/Velpatasvir/Voxilaprevir Gilead 8 weeks without cirrhosis or with cirrhosis in study POLARIS-2

a. Two patients without cirrhosis with undetermined genotype in the SOF/VEL/VOX group achieved SVR12.

b. One patient without cirrhosis had genotype 1 subtype other than genotype 1a or genotype 1b; the patient achieved SVR12.

c. SVR12 is 89% in genotype 1a patients enrolled at sites in the US and 97% in genotype 1a patients enrolled at sites outside the US

d. The denominator for relapse is the number of patients with HCV RNA <LLOQ at their last on-treatment assessment.

e. Other includes patients with missing data and those who discontinued treatment prior to virologic suppression.

DAA-naïve adults with genotype 3 HCV infection and compensated cirrhosis (POLARIS-3)

Table 14 presents the SVR12 and virologic outcome for the POLARIS-3 study.

Table 14: SVR12 and virologic outcome in study POLARIS-3 (HCV genotype 3 with compensated cirrhosis)*

* 29% of patients enrolled into POLARIS-3 had received prior treatment with an interferon-based regimen.

a. The denominator for relapse is the number of patients with HCV RNA < LLOQ at their last on-treatment assessment.

b. Other includes patients with missing data and those who discontinued treatment prior to virologic suppression.

Adults previously treated with sofosbuvir/velpatasvir-containing regimens

Sofosbuvir/Velpatasvir/Voxilaprevir Gilead for 12 weeks was evaluated in patients who were previously treated with a sofosbuvir/velpatasvir-containing regimen. The median time to re-treatment was 414 days (range 198-1271). Of the 31 patients enrolled, 74% (23/31) were male, 81% (25/31) were white, 71% (22/31) had a baseline body mass index < 30 kg/m², 48% (15/31) had compensated cirrhosis, 58% (18/31) had previously received sofosbuvir, velpatasvir and voxilaprevir, and 42% (13/31) had previously received sofosbuvir and velpatasvir. Most patients had genotype 1 (61% (19/31) [1a, 48% (15/31); 1b, 13% (4/31)]) or genotype 3 (26% (8/31)) HCV infection. The overall SVR12 rate was 100% (31/31).

Elderly

Clinical studies of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead included 189 patients aged 65 and over (17% of total number of patients in the Phase 2 and 3 clinical studies). The response rates observed for patients ≥ 65 years of age were similar to that of patients < 65 years of age, across treatment groups.

Paediatric population

The efficacy of 8 weeks of treatment with sofosbuvir/velpatasvir/voxilaprevir in HCV-infected paediatric patients aged 12 years and older was evaluated in a Phase 2, open-label clinical trial (Study 1175) in 21 DAA-naïve patients.

Of the 21 treated patients, the median age was 14 years (range: 12-16); 62% of the patients were female; 76% were White, 5% were Black, and 10% were Asian; 10% were Hispanic/Latino. Mean weight was 54 kg (range: 38-86 kg); mean body mass index was 20.5 kg/m² (range: 17-32 kg/m²); and 52% had baseline HCV RNA levels ≥ 800,000 IU/mL. The proportions of patients with genotype 1, 2, 3, and 4 HCV were 29%, 19%, 43%, and 10%; and no patients had known cirrhosis. The majority of patients (76%) had been infected through vertical transmission. The SVR12 rate was 100% overall.

Absorption

The pharmacokinetic properties of sofosbuvir, GS-331007, velpatasvir and voxilaprevir have been evaluated in healthy adult subjects and in patients with chronic hepatitis C.

Sofosbuvir

Following oral administration of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead, sofosbuvir was absorbed quickly and the peak median plasma concentration was observed 2 hours post-dose. Median peak plasma concentration of GS-331007 was observed 4 hours post-dose. Based on the population pharmacokinetic analysis in HCV-infected patients, mean steady-state AUC_0-24 and C_max for sofosbuvir (n = 1038) were 1665 ng•hr/mL and 678 ng/mL, respectively; mean steady-state AUC_0-24 and C_max for GS-331007 (n = 1593) were 12834 ng•hr/mL and 744 ng/mL, respectively. Sofosbuvir and GS-331007 AUC_0-24 and C_max were similar in healthy adult subjects and patients with HCV infection.

Velpatasvir

Velpatasvir median peak concentrations were observed at 4 hours post-dose. Based on the population pharmacokinetic analysis in HCV-infected patients mean steady- state AUC_0-24 and C_max for velpatasvir (n = 1595) were 4041 ng•hr/mL and 311 ng/mL, respectively. Relative to healthy subjects (n = 137), velpatasvir AUC_0-24 and C_max were 41% lower and 39% lower, respectively, in HCV-infected patients.

Voxilaprevir

Voxilaprevir median peak concentrations were observed 4 hours post-dose. Based on the population pharmacokinetic analysis in HCV-infected patients mean steady-state AUC_0-24 and C_max for voxilaprevir (n = 1591) were 2577 ng•hr/mL and 192 ng/mL, respectively. Relative to healthy subjects (n = 63), voxilaprevir AUC_0-24 and C_max were both 260% higher in HCV-infected patients.

Effects of food

When Sofosbuvir/Velpatasvir/Voxilaprevir Gilead or its components taken together were administered with food, sofosbuvir AUC_0-inf and C_max were 64% to 144% and 9% to 76% higher, respectively; velpatasvir AUC_0-inf and C_max were 40% to 166% and 37% to 187% higher, respectively; and voxilaprevir AUC_0-inf and C_max were 112% to 435% and 147% to 680% higher, respectively. GS-331007 AUC_0-inf did not change and C_max was 19% to 35% lower when Sofosbuvir/Velpatasvir/Voxilaprevir Gilead or its components together were administered with food.

Distribution

Sofosbuvir is approximately 61-65% bound to human plasma proteins and the binding is independent of drug concentration over the range of 1 μg/mL to 20 μg/mL. Protein binding of GS-331007 was minimal in human plasma. After a single 400 mg dose of [¹⁴C]-sofosbuvir in healthy subjects, the blood to plasma ratio of [¹⁴C]-radioactivity was approximately 0.7.

Velpatasvir is > 99% bound to human plasma proteins and binding is independent of drug concentration over the range of 0.09 μg/mL to 1.8 μg/mL. After a single 100 mg dose of [¹⁴C]-velpatasvir in healthy subjects, the blood to plasma ratio of [¹⁴C]-radioactivity ranged between 0.5 and 0.7.

Voxilaprevir is approximately > 99% bound to human plasma proteins. After a single 100 mg dose of [¹⁴C]-voxilaprevir in healthy subjects, the blood to plasma ratio of [¹⁴C]-radioactivity ranged between 0.5 and 0.8.

Biotransformation

Sofosbuvir is extensively metabolised in the liver to form the pharmacologically active nucleoside analogue triphosphate GS-461203. The metabolic activation pathway involves sequential hydrolysis of the carboxyl ester moiety catalysed by human cathepsin A (CatA) or carboxylesterase 1 (CES1) and phosphoramidate cleavage by histidine triad nucleotide-binding protein 1 (HINT1) followed by phosphorylation by the pyrimidine nucleotide biosynthesis pathway.

Dephosphorylation results in the formation of nucleoside metabolite GS-331007 that cannot be efficiently rephosphorylated and lacks anti-HCV activity in vitro. After a single 400 mg oral dose of [¹⁴C]-sofosbuvir, GS-331007 accounted for approximately > 90% of total systemic exposure.

Velpatasvir is primarily a substrate of CYP2B6, CYP2C8, and CYP3A4 with slow turnover. Following a single dose of 100 mg [¹⁴C]-velpatasvir, the majority (> 98%) of radioactivity in plasma was parent drug. The monohydroxylated and desmethylated velpatasvir were the metabolites identified in human plasma.

Unchanged velpatasvir is the major species present in faeces.

Voxilaprevir is primarily a substrate of CYP3A4 with slow turnover. Following a single dose of 100 mg [¹⁴C]-voxilaprevir, the majority (approximately 91%) of radioactivity in plasma was parent drug. The hydrolysed and dehydrogenated voxilaprevir were the major metabolites identified in human plasma. Unchanged voxilaprevir is the major species present in faeces.

Elimination

Following a single 400 mg oral dose of [¹⁴C]-sofosbuvir, mean total recovery of the [¹⁴C]-radioactivity was greater than 92%, consisting of approximately 80%, 14%, and 2.5% recovered in urine, faeces, and expired air, respectively. The majority of the sofosbuvir dose recovered in urine was GS-331007 (78%) while 3.5% was recovered as sofosbuvir. These data indicate that renal clearance is the major elimination pathway for GS-331007. The median terminal half-lives of sofosbuvir and GS-331007 following administration of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead were 0.5 and 29 hours, respectively.

Following a single 100 mg oral dose of [¹⁴C]-velpatasvir, mean total recovery of the [¹⁴C]-radioactivity was 95%, consisting of approximately 94% and 0.4% recovered from the faeces and urine, respectively. Unchanged velpatasvir was the major species in faeces accounting for a mean of 77% of the administered dose, followed by monohydroxylated velpatasvir (5.9%) and desmethylated velpatasvir (3.0%). These data indicate that biliary excretion of parent drug was a major route of elimination for velpatasvir. The median terminal half-life of velpatasvir following administration of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead was approximately 17 hours.

Following a single 100 mg oral dose of [¹⁴C]-voxilaprevir, mean total recovery of the [¹⁴C]-radioactivity was 94%, with all radioactivity measured in the faeces and none in the urine. Unchanged voxilaprevir was the major species in faeces accounting for a mean of 40% of the administered dose. Voxilaprevir metabolites also identified in faeces included des-[methylcyclopropylsulphonamide]-voxilaprevir (22.1%), which is formed intestinally, dehydro-voxilaprevir (7.5%), and two des- [methylcyclopropylsulphonamide]-oxy-voxilaprevir metabolites (5.4% and 3.9%).

Biliary excretion of parent drug was the major route of elimination for voxilaprevir. The median terminal half-life of voxilaprevir following administration of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead was approximately 33 hours.

Linearity/non-linearity

Sofosbuvir and GS-331007 AUCs are near dose-proportional over the dose range of 200 mg to 1200 mg. Velpatasvir AUC increases in a greater than proportional manner from 5 to 50 mg and in a less than proportional manner from 50 to 450 mg, indicating velpatasvir absorption is solubility limited. Voxilaprevir (studied under fed conditions) AUC increases in a greater than dose-proportional manner over the dose range of 100 to 900 mg.

In vitro potential for sofosbuvir/velpatasvir/voxilaprevir drug-drug interactions

Sofosbuvir, velpatasvir and voxilaprevir are substrates of drug transporters P-gp and BCRP while GS-331007 is not. Voxilaprevir, and to a lesser extent velpatasvir, are also substrates of OATP1B1 and OATP1B3. In vitro, slow metabolic turnover of velpatasvir primarily by CYP2B6, CYP2C8, and CYP3A4 and of voxilaprevir primarily by CYP3A4 was observed.

Sofosbuvir and GS-331007 are not inhibitors of drug transporters P-gp, BCRP, multidrug resistance-associated protein 2 (MRP2), bile salt export pump (BSEP), OATP1B1, OATP1B3 and organic cation transporter (OCT) 1 and GS-331007 is not an inhibitor of OAT1, OAT3, OCT2, and multidrug and toxin extrusion protein (MATE) 1. Sofosbuvir and GS-331007 are not inhibitors or inducers of CYP or uridine glucuronosyltransferase (UGT) 1A1 enzymes.

Velpatasvir is an inhibitor of drug transporter P-gp, BCRP, OATP1B1, OATP1B3 and OATP2B1, and its involvement in drug interactions with these transporters is primarily limited to the process of absorption. At clinically relevant concentrations, velpatasvir is not an inhibitor of hepatic transporters BSEP, sodium taurocholate cotransporter protein (NTCP), OATP1A2 or OCT1, renal transporters OCT2, OAT1, OAT3, MRP2 or MATE1, or CYP or UGT1A1 enzymes.

Voxilaprevir is an inhibitor of drug transporters P-gp, BCRP, OATP1B1 and OATP1B3, and its involvement in drug interactions with these transporters is primarily limited to the process of absorption. At clinically relevant concentrations, voxilaprevir is not an inhibitor of hepatic transporters OCT1, renal transporters OCT2, OAT1, OAT3 or MATE1, or CYP or UGT1A1 enzymes.

Pharmacokinetics in special populations

Race and gender

No clinically relevant pharmacokinetic differences due to race or gender have been identified for sofosbuvir, GS-331007, velpatasvir or voxilaprevir.

Elderly

Population pharmacokinetic analysis in HCV-infected patients showed that within the age range (18 to 85 years) analysed, age did not have a clinically relevant effect on the exposure to sofosbuvir, GS-331007, velpatasvir or voxilaprevir. In the 13 patients aged 75 to 84 years with available pharmacokinetic data, mean exposure to voxilaprevir was 93% higher than the mean exposure observed in patients aged 18 to 64 years.

Renal impairment

A summary of the effect of varying degrees of renal impairment (RI) on the exposures of the components of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead compared to subjects with normal renal function, as described in the text below, are provided in Table 15.

Table 15: Effect of Varying Degrees of Renal Impairment on Exposures (AUC) of SOF, GS - 331007, Velpatasvir and Voxilaprevir Compared to Subjects with Normal Renal Function

The pharmacokinetics of sofosbuvir was studied in HCV negative adult patients with mild (eGFR ≥ 50 and < 80 mL/min/1.73 m²), moderate (eGFR ≥ 30 and < 50 mL/min/1.73 m²), severe renal impairment (eGFR < 30 mL/min/1.73 m²) and patients with ESRD requiring haemodialysis following a single 400 mg dose of sofosbuvir, relative to patients with normal renal function (eGFR > 80 mL/min/1.73 m²). GS-331007 is efficiently removed by haemodialysis with an extraction coefficient of approximately 53%. Following a single 400 mg dose of sofosbuvir, a 4-hour haemodialysis removed 18% of administered dose.

In HCV-infected adult patients with severe renal impairment treated with sofosbuvir 200 mg with ribavirin (n=10) or sofosbuvir 400 mg with ribavirin (n=10) for 24 weeks or ledipasvir/sofosbuvir 90/400 mg (n=18) for 12 weeks, the pharmacokinetics of sofosbuvir and GS-331007 were consistent with that observed in HCV negative adult patients with severe renal impairment.

The pharmacokinetics of velpatasvir were studied with a single dose of 100 mg velpatasvir in HCV negative adult patients with severe renal impairment (eGFR < 30 mL/min by Cockcroft-Gault). Voxilaprevir is not renally eliminated.

Additionally, the pharmacokinetics of voxilaprevir were studied with a single dose of 100 mg voxilaprevir in HCV negative adult patients with severe renal impairment (eGFR < 30 mL/min by Cockcroft-Gault). The pharmacokinetics of voxilaprevir have not been studied in subjects with ESRD requiring dialysis (see section 4.2).

The pharmacokinetics of sofosbuvir, GS-331007, and velpatasvir were studied in HCV-infected patients with ESRD requiring dialysis treated with once daily sofosbuvir/velpatasvir 400/100 mg for 12 weeks and compared to patients without renal impairment in the sofosbuvir/velpatasvir Phase 2/3 studies.

Although exposures of the fixed-dose combination sofosbuvir, GS-331007, velpatasvir, and voxilaprevir were not directly evaluated in HCV-infected adult patients with ESRD requiring dialysis after administration of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead, the exposures of sofosbuvir, GS-331007, and velpatasvir are expected to be similar to those observed after administration of sofosbuvir/velpatasvir 400/100 mg in HCV-infected patients with ESRD requiring dialysis.

Hepatic impairment

The pharmacokinetics of sofosbuvir was studied following 7-day dosing of 400 mg sofosbuvir in HCV-infected adult patients with moderate and severe hepatic impairment (CPT Class B and C). Relative to patients with normal hepatic function, the sofosbuvir AUC_0-24 was 126% and 143% higher in patients with moderate and severe hepatic impairment, while the GS-331007 AUC_0-24 was 18% and 9% higher, respectively. Population pharmacokinetics analysis in HCV-infected adult patients indicated that cirrhosis (CPT Class A) had no clinically relevant effect on the exposure to sofosbuvir and GS-331007.

The pharmacokinetics of velpatasvir were studied with a single dose of 100 mg velpatasvir in HCV negative adult patients with moderate and severe hepatic impairment (CPT Class B and C). Velpatasvir plasma exposure (AUC_inf) was similar in patients with moderate hepatic impairment, severe hepatic impairment, and control subjects with normal hepatic function. Population pharmacokinetic analysis in HCV- infected adult patients indicated that cirrhosis (CPT Class A) had no clinically relevant effect on the exposure of velpatasvir.

The pharmacokinetics of voxilaprevir were studied with a single dose of 100 mg voxilaprevir in HCV negative adult patients with moderate and severe hepatic impairment (CPT Class B and C). Relative to patients with normal hepatic function, the voxilaprevir AUC_inf was 299% and 500% higher in patients with moderate and severe hepatic impairment, respectively. The unbound fraction of voxilaprevir was approximately 2-fold higher in severe hepatic impairment compared with moderate hepatic impairment or normal hepatic function. Population pharmacokinetic analysis in HCV-infected adult patients indicated that patients with cirrhosis (CPT Class A) had 73% higher exposure of voxilaprevir than those without cirrhosis (see section 4.2).

Body weight

In adults, body weight did not have a clinically significant effect on sofosbuvir, velpatasvir or voxilaprevir exposure according to a population pharmacokinetic analysis.

Paediatric population

Sofosbuvir, GS-331007, velpatasvir, and voxilaprevir exposures in paediatric patients aged 12 years and older receiving oral once daily doses of sofosbuvir/velpatasvir/voxilaprevir 400 mg/100 mg/100 mg were similar to those in adults.

The pharmacokinetics of Sofosbuvir/Velpatasvir/Voxilaprevir Gilead in paediatric patients aged less than 12 years and weighing less than 30 kg have not been established (see section 4.2).

Sofosbuvir

Sofosbuvir was not genotoxic in a battery of in vitro or in vivo assays, including bacterial mutagenicity, chromosome aberration using human peripheral blood lymphocytes and in vivo mouse micronucleus assays. No teratogenic effects were observed in the rat and rabbit developmental toxicity studies with sofosbuvir.

Sofosbuvir had no adverse effects on behaviour, reproduction, or development of the offspring in the rat pre- and post-natal development study.

Sofosbuvir was not carcinogenic in the 2-year mouse and rat carcinogenicity studies at GS-331007 exposures up to 17 and 10-times higher, respectively than human exposure.

Velpatasvir

Velpatasvir was not genotoxic in a battery of in vitro or in vivo assays, including bacterial mutagenicity, chromosome aberration using human peripheral blood lymphocytes and in vivo rat micronucleus assays.

Velpatasvir was not carcinogenic in the 26-week transgenic mouse and 2-year rat carcinogenicity studies at exposures up to 67- and 5-times higher than human exposure, respectively.

Velpatasvir had no adverse effects on mating and fertility. No teratogenic effects were observed in the mouse and rat developmental toxicity studies with velpatasvir at AUC exposures approximately 23- and 4-fold higher, respectively, than the human exposure at the recommended clinical dose. However, a possible teratogenic effect was indicated in rabbits where an increase in total visceral malformations was seen in exposed animals at AUC exposures up to 0.5 fold the human exposure at recommended clinical dose. The human relevance of this finding is not known.

Velpatasvir had no adverse effects on behaviour, reproduction, or development of the offspring in the rat pre- and post-natal development study at AUC exposures approximately 3-fold higher than the human exposure at the recommended clinical dose.

Voxilaprevir

Voxilaprevir was not genotoxic in a battery of in vitro or in vivo assays, including bacterial mutagenicity, chromosome aberration using human peripheral blood lymphocytes and in vivo rat micronucleus assays.

Carcinogenicity studies for voxilaprevir have not been conducted.

Voxilaprevir had no adverse effects on mating and fertility. No teratogenic effects were observed in the rat and rabbit developmental toxicity studies with voxilaprevir at AUC exposures approximately 141- and 4-times higher, respectively, than the human exposure at the recommended clinical dose. Voxilaprevir had no adverse effects on behavior, reproduction, or development of the offspring in the rat pre- and post-natal development study at AUC exposures approximately 238-times higher than the human exposure at the recommended clinical dose.

Tablet core

Colloidal anhydrous silica

Copovidone

Croscarmellose sodium (E468)

Lactose monohydrate

Magnesium stearate

Microcrystalline cellulose (E460)

Film-coating

Iron oxide black (E172)

Iron oxide red (E172)

Iron oxide yellow (E172)

Macrogol (E1521)

Polyvinyl alcohol (E1203)

Talc (E553b)

Titanium dioxide (E171)

Not applicable.

4 years.

This medicinal product does not require any special temperature storage conditions. Store in the original package in order to protect from moisture. Keep the bottle tightly closed.

High density polyethylene (HDPE) bottle with a polypropylene child-resistant closure containing 28 film-coated tablets with polyester coil and a silica gel desiccant.

Pack size: outer carton containing 1 bottle of 28 film-coated tablets.

Any unused medicinal product or waste material should be disposed of in accordance with local requirements.