CLINICAL PHARMACOLOGY
Mechanism Of Action
HARVONI is a fixed-dose combination of ledipasvir and sofosbuvir which are direct-acting antiviral agents against the hepatitis C virus [see Microbiology].
Pharmacodynamics
Cardiac Electrophysiology
Thorough QT studies have been conducted for ledipasvir and sofosbuvir.
The effect of ledipasvir 120 mg twice daily (2.67 times the maximum recommended dosage) for 10 days on QTc interval was evaluated in a randomized, multiple-dose, placebo-, and active-controlled (moxifloxacin 400 mg) three period crossover thorough QT trial in 59 healthy subjects. At the dose of 120 mg twice daily (2.67 times the maximum recommended dosage), ledipasvir does not prolong QTc interval to any clinically relevant extent.
The effect of sofosbuvir 400 mg (maximum recommended dosage) and 1200 mg (three times the maximum recommended dosage) on QTc interval was evaluated in a randomized, single-dose, placebo-, and active-controlled (moxifloxacin 400 mg) four period crossover thorough QT trial in 59 healthy subjects. At a dose three times the maximum recommended dose, sofosbuvir does not prolong QTc to any clinically relevant extent.
Pharmacokinetics
Absorption
The pharmacokinetic properties of ledipasvir, sofosbuvir, and the predominant circulating metabolite GS-331007 have been evaluated in healthy adult subjects and in subjects with chronic hepatitis C. Following oral administration of HARVONI, ledipasvir median peak concentrations were observed 4 to 4.5 hours post-dose. Sofosbuvir was absorbed quickly and the peak median plasma concentration was observed ~0.8 to 1 hour post-dose. Median peak plasma concentration of GS-331007 was observed between 3.5 to 4 hours post-dose.
Based on the population pharmacokinetic analysis in HCV-infected subjects, geometric mean steady-state AUC0-24 for ledipasvir (N=2113), sofosbuvir (N=1542), and GS-331007 (N=2113) were 7290, 1320, and 12,000 ng•hr/mL, respectively. Steady-state Cmax for ledipasvir, sofosbuvir, and GS-331007 were 323, 618, and 707 ng/mL, respectively. Sofosbuvir and GS-331007 AUC0-24 and Cmax were similar in healthy adult subjects and subjects with HCV infection. Relative to healthy subjects (N=191), ledipasvir AUC0-24 and Cmax were 24% lower and 32% lower, respectively, in HCV-infected subjects.
Effect Of Food
Relative to fasting conditions, the administration of a single dose of HARVONI with a moderate fat (~600 kcal, 25% to 30% fat) or high fat (~1000 kcal, 50% fat) meal increased sofosbuvir AUC0-inf by approximately 2-fold, but did not significantly affect sofosbuvir Cmax. The exposures of GS-331007 and ledipasvir were not altered in the presence of either meal type. The response rates in Phase 3 trials were similar in HCV-infected subjects who received HARVONI with food or without food. HARVONI can be administered without regard to food.
Distribution
Ledipasvir is greater than 99.8% bound to human plasma proteins. After a single 90 mg dose of [14C]-ledipasvir in healthy subjects, the blood to plasma ratio of 14C-radioactivity ranged between 0.51 and 0.66.
Sofosbuvir is approximately 61–65% bound to human plasma proteins and the binding is independent of drug concentration over the range of 1 microgram/mL to 20 microgram/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.
Metabolism
In vitro, no detectable metabolism of ledipasvir was observed by human CYP1A2, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP3A4. Evidence of slow oxidative metabolism via an unknown mechanism has been observed. Following a single dose of 90 mg [14C]-ledipasvir, systemic exposure was almost exclusively to the parent drug (greater than 98%). Unchanged ledipasvir is the major species present in feces.
Sofosbuvir is extensively metabolized in the liver to form the pharmacologically active nucleoside analog triphosphate GS-461203. The metabolic activation pathway involves sequential hydrolysis of the carboxyl ester moiety catalyzed 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 greater than 90% of total systemic exposure.
Elimination
Following a single 90 mg oral dose of [14C]-ledipasvir, mean total recovery of the [14C]-radioactivity in feces and urine was approximately 87%, with most of the radioactive dose recovered from feces (approximately 86%). Unchanged ledipasvir excreted in feces accounted for a mean of 70% of the administered dose and the oxidative metabolite M19 accounted for 2.2% of the dose. These data indicate that biliary excretion of unchanged ledipasvir is a major route of elimination, with renal excretion being a minor pathway (approximately 1%). The median terminal half-life of ledipasvir following administration of HARVONI was 47 hours.
Following a single 400 mg oral dose of [14C]-sofosbuvir, mean total recovery of the dose was greater than 92%, consisting of approximately 80%, 14%, and 2.5% recovered in urine, feces, 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 HARVONI were 0.5 and 27 hours, respectively.
Specific Populations
Race
Population pharmacokinetics analysis in HCV-infected subjects indicated that
race had no clinically relevant effect on the exposure of ledipasvir, sofosbuvir, and
GS-331007.
Gender
Population pharmacokinetics analysis in HCV-infected subjects indicated
that gender had no clinically relevant effect on the exposure of sofosbuvir and
GS-331007. AUC and Cmax of ledipasvir were 77% and 58% higher, respectively, in
females than males; however, the relationship between gender and ledipasvir
exposures was not considered clinically relevant, as high response rates
(SVR12 >90%) were achieved in male and female subjects across the Phase 3
studies and the safety profiles are similar in females and males.
Pediatric Patients
The pharmacokinetics of ledipasvir, sofosbuvir, and GS-331007 were determined in HCV genotype 1, 3, or 4 infected pediatric subjects 3 years of age and older receiving a daily dose of HARVONI as described below in Table 7. Exposures in pediatric subjects were similar to those observed in adults.
Table 7 - Pharmacokinetic Properties of the Components of HARVONI in HCV-Infected Pediatric Subjects 3 Years of Age and Oldera
Weight Group |
Dose |
PK Parameter |
Geometric Mean (%CV) |
Ledipasvir |
Sofosbuvir |
GS-331007 |
≥35 kgb |
90/400 mg |
AUCtau (ng•hr/mL) |
11200 (45.7) |
1350 (45.2) |
13600 (18.9) |
Cmax (ng/mL) |
550 (44.2) |
660 (51.1) |
921 (17.8) |
17 to <35 kgc |
45/200 mg |
AUCtau (ng•hr/mL) |
8750 (46.6) |
1420 (34.2) |
10700 (30.9) |
Cmax (ng/mL) |
440 (42.7) |
690 (24.8) |
958 (26.1) |
<17 kgd |
33.75/150 mg |
AUCtau (ng•hr/mL) |
7460 (31.0) |
1720 (23.2) |
12200 (15.2) |
Cmax (ng/mL) |
405 (25.7) |
791 (16.6) |
1070 (13.0) |
a.Population PK derived parameters
b.Ledipasvir N=100; Sofosbuvir N=72; GS-331007 N=100
c.Ledipasvir N=86; Sofosbuvir N=66; GS-331007 N=86
d.Ledipasvir N=9; Sofosbuvir N=9; GS-331007 N=9 |
The pharmacokinetics of ledipasvir, sofosbuvir, and GS-331007 have not been established in pediatric subjects less than 3 years of age [see Use In Specific Populations, and Clinical Studies].
Geriatric Patients
Population pharmacokinetic analysis in HCV-infected subjects showed that within the age range (18 to 80 years) analyzed, age did not have a clinically relevant effect on the exposure to ledipasvir, sofosbuvir, and GS-331007 [see Use In Specific Populations].
Patients With Renal Impairment
The pharmacokinetics of ledipasvir were studied with a single dose of 90 mg ledipasvir in HCV negative subjects with severe renal impairment (eGFR less than 30 mL/min by Cockcroft-Gault). No clinically relevant differences in ledipasvir pharmacokinetics were observed between healthy subjects and subjects with severe renal impairment.
The pharmacokinetics of sofosbuvir were studied in HCV negative subjects with mild (eGFR between 50 to less than 80 mL/min/1.73 m2), moderate (eGFR between 30 to less than 50 mL/min/1.73 m2), severe renal impairment (eGFR less than 30 mL/min/1.73 m2), and subjects with ESRD requiring hemodialysis following a single 400 mg dose of sofosbuvir. Relative to subjects with normal renal function (eGFR greater than 80 mL/min/1.73 m2), the sofosbuvir AUC0-inf was 61%, 107%, and 171% higher in mild, moderate, and severe renal impairment, while the GS-331007 AUC0-inf was 55%, 88%, and 451% higher, respectively. In subjects with ESRD, relative to subjects with normal renal function, sofosbuvir and GS-331007 AUC0-inf was 28% and 1280% higher when sofosbuvir was dosed 1 hour before hemodialysis compared with 60% and 2070% higher when sofosbuvir was dosed 1 hour after hemodialysis, respectively. A 4 hour hemodialysis session removed approximately 18% of administered dose [see DOSAGE AND ADMINISTRATIONand Use In Specific Populations].
Patients With Hepatic Impairment
The pharmacokinetics of ledipasvir were studied with a single dose of 90 mg ledipasvir in HCV negative subjects with severe hepatic impairment (Child-Pugh Class C). Ledipasvir plasma exposure (AUC0-inf) was similar in subjects with severe hepatic impairment and control subjects with normal hepatic function. Population pharmacokinetics analysis in HCV-infected subjects indicated that cirrhosis (including decompensated cirrhosis) had no clinically relevant effect on the exposure of ledipasvir [see Use In Specific Populations].
The pharmacokinetics of sofosbuvir were studied following 7-day dosing of 400 mg sofosbuvir in HCV-infected subjects with moderate and severe hepatic impairment (Child-Pugh Class B and C). Relative to subjects with normal hepatic function, the sofosbuvir AUC0-24 were 126% and 143% higher in moderate and severe hepatic impairment, while the GS-331007 AUC0-24 were 18% and 9% higher, respectively. Population pharmacokinetics analysis in HCV-infected subjects indicated that cirrhosis (including decompensated cirrhosis) had no clinically relevant effect on the exposure of sofosbuvir and GS-331007 [see Use In Specific Populations and Clinical Studies].
Drug Interaction Studies
Ledipasvir and sofosbuvir are substrates of drug transporters P-gp and BCRP while GS-331007 is not. P-gp inducers (e.g., rifampin or St. John’s wort) may decrease ledipasvir and sofosbuvir plasma concentrations, leading to reduced therapeutic effect of HARVONI, and the use with P-gp inducers is not recommended with HARVONI [see WARNINGS AND PRECAUTIONS]. Coadministration with drugs that inhibit P-gp and/or BCRP may increase ledipasvir and sofosbuvir plasma concentrations without increasing GS-331007 plasma concentration; HARVONI may be coadministered with P-gp and/or BCRP inhibitors. Neither ledipasvir nor sofosbuvir is a substrate for hepatic uptake transporters OCT1, OATP1B1, or OATP1B3. GS-331007 is not a substrate for renal transporters, including organic anion transporter OAT1 or OAT3, or organic cation transporter OCT2.
Ledipasvir is subject to slow oxidative metabolism via an unknown mechanism. In vitro, no detectable metabolism of ledipasvir by CYP enzymes has been observed. Biliary excretion of unchanged ledipasvir is a major route of elimination. Sofosbuvir is not a substrate for CYP and UGT1A1 enzymes. Clinically significant drug interactions with HARVONI mediated by CYP or UGT1A1 enzymes are not expected.
The effects of coadministered drugs on the exposure of ledipasvir, sofosbuvir, and GS-331007 are shown in Table 8 [see DRUG INTERACTIONS].
Table 8 - Drug Interactions: Changes in Pharmacokinetic Parameters for Ledipasvir, Sofosbuvir, and the Predominant Circulating Metabolite GS-331007 in the Presence of the Coadministered Druga
Coadministered Drug |
Dose of Coadminis tered Drug (mg) |
Ledipasvir Dose (mg) |
Sofos -buvir Dose (mg) |
N |
Mean Ratio (90% CI) of Ledipasvir, Sofosbuvir, and GS-331007 PK With/Without Coadministered Drug No Effect=1.00 |
|
Cmax |
AUC |
Cmin |
Atazanavir/ ritonavir + emtricitabine/ tenofovir DFb,c |
300/100 + 200/300 once daily |
90 once daily |
400 once daily |
24 |
ledipasvir |
1.68 (1.54, 1.84) |
1.96 (1.74, 2.21) |
2.18 (1.91, 2.50) |
sofosbuvir |
1.01 (0.88, 1.15) |
1.11 (1.02, 1.21) |
NA |
GS-331007 |
1.17 (1.12, 1.23) |
1.31 (1.25, 1.36) |
1.42 (1.34, 1.49) |
Cyclosporine |
600 single dose |
ND |
400 single dose |
19 |
sofosbuvir |
2.54 (1.87, 3.45) |
4.53 (3.26, 6.30) |
NA |
GS-331007 |
0.60 (0.53, 0.69) |
1.04 (0.90, 1.20) |
NA |
Darunavir/ ritonavir |
800/100 once daily |
90 once daily |
ND |
23 |
ledipasvir |
1.45 (1.34, 1.56) |
1.39 (1.28, 1.49) |
1.39 (1.29, 1.51) |
ND |
400 single dose |
18 |
sofosbuvir |
1.45 (1.10, 1.92) |
1.34 (1.12, 1.59) |
NA |
GS-331007 |
0.97 (0.90, 1.05) |
1.24 (1.18, 1.30) |
NA |
Darunavir/ ritonavir + emtricitabine/ tenofovir DFb |
800/100 + 200/300 once daily |
90 once daily |
400 once daily |
23 |
ledipasvir |
1.11 (0.99, 1.24) |
1.12 (1.00, 1.25) |
1.17 (1.04, 1.31) |
sofosbuvir |
0.63 (0.52, 0.75) |
0.73 (0.65, 0.82) |
NA |
GS-331007 |
1.10 (1.04, 1.16) |
1.20 (1.16, 1.24) |
1.26 (1.20, 1.32) |
Efavirenz/ emtricitabine/ tenofovir DFd |
600/200/300 once daily |
90 once daily |
400 once daily |
14 |
ledipasvir |
0.66 (0.59, 0.75) |
0.66 (0.59, 0.75) |
0.66 (0.57, 0.76) |
sofosbuvir |
1.03 (0.87, 1.23) |
0.94 (0.81, 1.10) |
NA |
GS-331007 |
0.86 (0.76, 0.96) |
0.90 (0.83, 0.97) |
1.07 (1.02, 1.13) |
Elvitegravir/ cobicistat/ emtricitabine/ tenofovir alafenamide |
150/150/200 /10 once daily |
90 once daily |
400 once daily |
30 |
ledipasvir |
1.65 (1.53, 1.78) |
1.79 (1.64, 1.96) |
1.93 (1.74, 2.15) |
sofosbuvir |
1.28 (1.13, 1.47) |
1.47 (1.35,1.59) |
NA |
GS-331007 |
1.29 (1.24, 1.35) |
1.48 (1.44, 1.53) |
1.66 (1.60, 1.73) |
Famotidine |
40 single dose simultaneou sly with HARVONI |
90 single dose |
400 single dose |
12 |
ledipasvir |
0.80 (0.69, 0.93) |
0.89 (0.76, 1.06) |
NA |
sofosbuvir |
1.15 (0.88, 1.50) |
1.11 (1.00, 1.24) |
NA |
GS-331007 |
1.06 (0.97, 1.14) |
1.06 (1.02, 1.11) |
NA |
40 single dose 12 hours prior to HARVONI |
12 |
ledipasvir |
0.83 (0.69, 1.00) |
0.98 (0.80, 1.20) |
NA |
sofosbuvir |
1.00 (0.76, 1.32) |
0.95 (0.82, 1.10) |
NA |
GS-331007 |
1.13 (1.07, 1.20) |
1.06 (1.01, 1.12) |
NA |
Methadone |
30 to 130 daily |
ND |
400 once daily |
14 |
sofosbuvir |
0.95 (0.68, 1.33) |
1.30 (1.00, 1.69) |
NA |
GS-331007 |
0.73 (0.65, 0.83) |
1.04 (0.89, 1.22) |
NA |
Omeprazole |
20 once daily simultaneou sly with HARVONI |
90 single dose |
400 single dose |
16 |
ledipasvir |
0.89 (0.61, 1.30) |
0.96 (0.66, 1.39) |
NA |
sofosbuvir |
1.12 (0.88, 1.42) |
1.00 (0.80, 1.25) |
NA |
GS-331007 |
1.14 (1.01, 1.29) |
1.03 (0.96, 1.12) |
NA |
20 once daily 2 hours prior to ledipasvir |
30 single dose |
ND |
17 |
ledipasvir |
0.52 (0.41, 0.66) |
0.58 (0.48, 0.71) |
NA |
Rifampin |
600 once daily |
90 single dosee |
ND |
31 |
ledipasvir |
0.65 (0.56, 0.76) |
0.41 (0.36, 0.48) |
NA |
ND |
400 single dose |
17 |
sofosbuvir |
0.23 (0.19, 0.29) |
0.28 (0.24, 0.32) |
NA |
GS-331007 |
1.23 (1.14, 1.34) |
0.95 (0.88, 1.03) |
NA |
Simeprevir |
150 once daily |
30 once daily |
ND |
22 |
ledipasvir |
1.81 (1.69, 2.94) |
1.92 (1.77, 2.07) |
NA |
Tacrolimus |
5 single dose |
ND |
400 single dose |
16 |
sofosbuvir |
0.97 (0.65, 1.43) |
1.13 (0.81, 1.57) |
NA |
GS-331007 |
0.97 (0.83, 1.14) |
1.00 (0.87, 1.13) |
NA |
NA = not available/not applicable, ND = not dosed.
tenofovir DF = tenofovir disoproxil fumarate
a.All interaction studies conducted in healthy volunteers.
b.Data generated from simultaneous dosing with HARVONI. Staggered administration (12 hours apart) of atazanavir/ritonavir + emtricitabine/tenofovir DF or darunavir/ritonavir + emtricitabine/tenofovir DF and HARVONI provided similar results.
c.The effects of atazanavir/ritonavir on ledipasvir and sofosbuvir are similar with or without the presence of emtricitabine/tenofovir DF.
d.Administered as ATRIPLA® (efavirenz, emtricitabine, tenofovir DF).
e.This study was conducted in the presence of two other investigational HCV direct-acting agents. |
No effect on the pharmacokinetic parameters of ledipasvir, sofosbuvir, and GS-331007 was observed with raltegravir and the combination of abacavir and lamivudine; emtricitabine, rilpivirine, and tenofovir disoproxil fumarate; or dolutegravir, emtricitabine, and tenofovir disoproxil fumarate.
Ledipasvir is an inhibitor of drug transporter P-gp and breast cancer resistance protein (BCRP) and may increase intestinal absorption of coadministered substrates for these transporters. Ledipasvir is an inhibitor of transporters OATP1B1, OATP1B3, and BSEP only at concentrations exceeding those achieved in clinic. Ledipasvir is not an inhibitor of transporters MRP2, MRP4, OCT2, OAT1, OAT3, MATE1, and OCT1. The drug-drug interaction potential of ledipasvir is primarily limited to the intestinal inhibition of P-gp and BCRP. Clinically relevant transporter inhibition by ledipasvir in the systemic circulation is not expected due to its high protein binding. Sofosbuvir and GS-331007 are not inhibitors of drug transporters P-gp, BCRP, MRP2, BSEP, OATP1B1, OATP1B3, and OCT1, and GS-331007 is not an inhibitor of OAT1, OCT2, and MATE1.
Ledipasvir, sofosbuvir, and GS-331007 are not inhibitors or inducers of CYP or UGT1A1 enzymes.
The effects of ledipasvir or sofosbuvir on the exposure of coadministered drugs are shown in Table 9 [see DRUG INTERACTIONS].
Table 9 - Drug Interactions: Changes in Pharmacokinetic Parameters for Coadministered Drug in the Presence of Ledipasvir, Sofosbuvir, or HARVONIa
Coadministered Drug |
Dose of Coadministered Drug (mg) |
Ledipasvir Dose (mg) |
Sofosbuvir Dose (mg) |
N |
Mean Ratio (90% CI) of Coadministered Drug PK With/Without Ledipasvir, Sofosbuvir, or HARVONI
No Effect=1.00 |
Cmax |
AUC |
Cmin |
Atazanavir/ ritonavir + emtricitabine /tenofovir DFb,c,d |
atazanavir 300 once daily |
90 once daily |
400 once daily |
24 |
1.07
(0.99, 1.14) |
1.27
(1.18, 1.37) |
1.63
(1.45, 1.84) |
ritonavir 100 once daily |
0.86
(0.79, 0.93) |
0.97
(0.89, 1.05) |
1.45
(1.27, 1.64) |
tenofovir DF 300 once daily |
1.47
(1.37, 1.58) |
1.35
(1.29, 1.42) |
1.47
(1.38, 1.57) |
Darunavir/ ritonavir + emtricitabine/ tenofovir DFb,d |
darunavir 800 once daily |
90 once daily |
400 once daily |
23 |
1.01
(0.96, 1.06) |
1.04
(0.99, 1.08) |
1.08
(0.98, 1.20) |
ritonavir 100 once daily |
1.17
(1.01, 1.35) |
1.25
(1.15, 1.36) |
1.48
(1.34, 1.63) |
tenofovir DF 300 once daily |
1.64
(1.54, 1.74) |
1.50
(1.42, 1.59) |
1.59
(1.49, 1.70) |
Elvitegravir/ cobicistat/ emtricitabine/ tenofovir alafenamide |
elvitegravir 150 once daily |
90 once daily |
400 once daily |
30 |
0.98
(0.90, 1.07) |
1.11
(1.02, 1.20) |
1.46
(1.28, 1.66) |
cobicistat 150 once daily |
1.23
(1.15, 1.32) |
1.53
(1.45, 1.62) |
3.25
(2.88, 3.67) |
tenofovir alafenamide 10 once daily |
0.90
(0.73, 1.11) |
0.86
(0.78, 0.95) |
NA |
Norelgestromin |
norgestimate 0.180/0.215/0.25/ ethinyl estradiol 0.025 once daily |
90 once daily |
ND |
15 |
1.02
(0.89, 1.16) |
1.03
(0.90, 1.18) |
1.09
(0.91, 1.31) |
ND |
400 once daily |
1.07
(0.94, 1.22) |
1.06
(0.92, 1.21) |
1.07
(0.89, 1.28) |
Norgestrel |
90 once daily |
ND |
1.03
(0.87, 1.23) |
0.99
(0.82, 1.20) |
1.00
(0.81, 1.23) |
ND |
400 once daily |
1.18
(0.99, 1.41) |
1.19
(0.98, 1.45) |
1.23
(1.00, 1.51) |
Ethinyl estradiol |
90 once daily |
ND |
1.40
(1.18, 1.66) |
1.20
(1.04, 1.39) |
0.98
(0.79, 1.22) |
ND |
400 once daily |
1.15
(0.97, 1.36) |
1.09
(0.94, 1.26) |
0.99
(0.80, 1.23) |
Raltegravir |
400 twice daily |
90 once daily |
ND |
28 |
0.82
(0.66, 1.02) |
0.85
(0.70, 1.02) |
1.15
(0.90, 1.46) |
ND |
400 single dose |
19 |
0.57
(0.44, 0.75) |
0.73
(0.59, 0.91) |
0.95
(0.81, 1.12) |
Simeprevir |
150 once daily |
30 once daily |
ND |
22 |
2.61
(2.39, 2.86) |
2.69
(2.44, 2.96) |
NA |
Tacrolimus |
5 single dose |
ND |
400 single dose |
16 |
0.73
(0.59, 0.90) |
1.09
(0.84, 1.40) |
NA |
Tenofovir DF |
300 once dailye |
90 once daily |
400 once daily |
15 |
1.79
(1.56, 2.04) |
1.98
(1.77, 2.23) |
2.63
(2.32, 2.97) |
NA = not available/not applicable, ND = not dosed. tenofovir DF = tenofovir disoproxil fumarate
a.All interaction studies conducted in healthy volunteers.
b.Data generated from simultaneous dosing with HARVONI. Staggered administration (12 hours apart) of atazanavir/ritonavir + emtricitabine/tenofovir DF or darunavir/ritonavir + emtricitabine/tenofovir DF and HARVONI provided similar results.
c.The effects of HARVONI on atazanavir and ritonavir are similar with or without the presence of emtricitabine/tenofovir DF.
d.This magnitude of change in tenofovir exposure does not reflect the approximately 60–80% increase caused by the effects of an HIV PI/ritonavir and the effect of food. Therefore, tenofovir exposure is approximately 130% higher when administered as tenofovir DF + atazanavir/ritonavir + HARVONI or tenofovir DF + darunavir/ritonavir
+ HARVONI and with food as compared to the tenofovir exposure observed following fasted administration of tenofovir DF-based regimens that do not contain an HIV PI/ritonavir and HARVONI.
e.Administered as ATRIPLA (efavirenz, emtricitabine, tenofovir DF). The effects of HARVONI on tenofovir exposures are similar when tenofovir is administered as ATRIPLA, COMPLERA, or TRUVADA + dolutegravir. |
No effect on the pharmacokinetic parameters of the following coadministered drugs was observed with ledipasvir or sofosbuvir: abacavir, cyclosporine, darunavir/ritonavir, dolutegravir, efavirenz, emtricitabine, lamivudine, methadone, or rilpivirine.
Microbiology
Mechanism Of Action
Ledipasvir is an inhibitor of the HCV NS5A protein, which is required for viral replication. Resistance selection in cell culture and cross-resistance studies indicate ledipasvir targets NS5A as its mode of action.
Sofosbuvir is an 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 analog 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 genotypes 1b and 4a with IC50 values of 3.3 and 2.7 microM, respectively. GS-461203 is neither an inhibitor of human DNA and RNA polymerases nor an inhibitor of mitochondrial RNA polymerase.
Antiviral Activity
In HCV replicon assays, the EC50 values of ledipasvir against full-length replicons from genotypes 1a and 1b were 0.031 nM and 0.004 nM, respectively. The median EC50 values of ledipasvir against chimeric replicons encoding NS5A sequences from clinical isolates from treatment-naïve HCV-infected subjects were 0. 02 nM for genotype 1a (range 0.007–1.0 nM; N=23) and 0.006 nM for genotype 1b (range 0.002–1.0 nM; N=34). Ledipasvir had median EC50 values ranging between 0.002 nM to 0.16 nM against 11 genotype 4 subtypes (4a, 4d, 4n, 4r, 4o, 4c, 4f, 4k, 4l, 4m and 4t). The median EC50 value for subtype 4b was 199.6 nM (range 0.66-1799 nM; N=3); the two 4b isolates with EC50 values greater than 100 nM had NS5A resistance-associated polymorphisms L30S+M31M+P58S+Y93H. The median EC50 value of ledipasvir was
0.03 nM against genotype 5a isolates (range 0.008–0.081 nM; N=35). For genotype 6, the EC50 values for ledipasvir varied by subtype. Subtypes 6a and 6h had median EC50 values of 0.55 and 0.17 nM, respectively. For subtypes 6e, 6l, 6n, 6q, 6k and 6m, the median EC50 values ranged from 60.6 nM to 430.1 nM.
In HCV replicon assays, the EC50 values of sofosbuvir against full-length replicons from genotypes 1a, 1b, and 4a, and chimeric 1b replicons encoding NS5B from genotypes 5a or 6a ranged from 14–110 nM. The median EC50 value of sofosbuvir against chimeric replicons encoding NS5B sequences from clinical isolates was 62 nM for genotype 1a (range 29–128 nM; N=67) and 102 nM for genotype 1b (range 45–170 nM; N=29). In replication competent virus assays, the EC50 value of sofosbuvir against genotype 1a was 30 nM. Evaluation of sofosbuvir in combination with ledipasvir showed no antagonistic effect in reducing HCV RNA levels in replicon cells.
Resistance
In Cell Culture
HCV replicons with reduced susceptibility to ledipasvir have been selected in cell culture for genotypes 1a and 1b. Reduced susceptibility to ledipasvir was associated with the primary NS5A amino acid substitution Y93H in both genotypes 1a and 1b. Additionally, a Q30E substitution emerged in genotype 1a replicons. Site-directed mutagenesis of the Y93H in both genotypes 1a and 1b, as well as the Q30E substitution in genotype 1a, conferred high levels of reduced susceptibility to ledipasvir (fold change in EC50 greater than 1000-fold).
HCV replicons with reduced susceptibility to sofosbuvir have been selected in cell culture for multiple genotypes including 1b, 4a, 5a, and 6a. Reduced susceptibility to sofosbuvir was associated with the NS5B substitution S282T in all replicon genotypes examined. An m289L substitution developed along with the S282T substitution in genotype 5 and 6 replicons. Site-directed mutagenesis of the S282T substitution in replicons of 8 genotypes conferred 2- to 18-fold reduced susceptibility to sofosbuvir.
In Clinical Trials
Genotype 1
In a pooled analysis of subjects who received HARVONI in Phase 3 trials (ION-3, ION-1, and ION-2), 37 subjects (29 with genotype 1a HCV and 8 with genotype 1b HCV) qualified for resistance analysis due to virologic failure (35 with virologic relapse, 2 with breakthrough on-treatment due to documented non-adherence). Post-baseline NS5A and NS5B deep nucleotide sequence analysis data (assay sensitivity of 1%) were available for 37/37 and 36/37 subjects’ viruses, respectively.
Of the 29 genotype 1a virologic failure subjects, 55% (16/29) of subjects had virus with emergent NS5A resistance-associated substitutions K24R, m28T/V, Q30R/H/K/L, L31M, or Y93H/N at failure. Five of these 16 subjects’ viruses also had baseline NS5A polymorphisms at resistance-associated amino acid positions. The most common substitutions detected at failure were Q30R, Y93H or N, and L31M.
Of the 8 genotype 1b virologic failure subjects, 88% (7/8) had virus with emergent NS5A resistance-associated substitutions L31V/M/I or Y93H at failure. Virus from three of these 7 subjects also had baseline NS5A polymorphisms at resistance-associated positions. The most common substitution detected at failure was Y93H.
At failure, 38% (14/37) of virologic failure subjects’ viruses had 2 or more NS5A substitutions at resistance-associated positions.
In the SOLAR-1 and SOLAR-2 trials (liver transplant recipients or subjects with decompensated liver disease), there were 24 virologic failures with genotype 1 infection (20 relapsers and 4 subjects who discontinued treatment prior to achieving HCV RNA <LLOQ). Treatment-emergent NS5A resistance-associated substitutions K24R, m28T, Q30R/H/K, L31V, H58D/P, and/or Y93H/C were detected in 14/17 (82%) genotype 1a virologic failure subjects, and R30Q, L31M, and/or Y93H/N were detected in 6/7 (86%) genotype 1b virologic failure subjects.
In phenotypic analyses, post-baseline isolates from subjects who harbored NS5A resistance-associated substitutions at failure showed 20- to >243-fold reduced susceptibility to ledipasvir.
Treatment-emergent NS5B substitutions L159 (n=1) and V321 (n=2) previously associated with sofosbuvir failure were detected in the Phase 3 trials (ION-3, ION-1, and ION-2). In addition, treatment-emergent NS5B substitutions at highly conserved positions D61G (n=3), A112T (n=2), E237G (n=2), and S473T (n=1) were detected at low frequency by next generation sequencing in treatment failure subjects infected with HCV genotype 1a. The D61G substitution was previously described in subjects infected with HCV genotype 1a in a liver pre-transplant trial. The E237G substitution was detected in 3 subjects infected with HCV GT1a in the SOLAR-1 and SOLAR-2 trials. The clinical significance of these substitutions is currently unknown. The sofosbuvir-associated resistance substitution S282T in NS5B was not detected in any failure isolate from the Phase 3 trials. NS5B substitutions S282T, L320V/I, and V321I in combination with NS5A substitutions L31M, Y93H, and Q30L were detected in one subject at failure following 8 weeks of treatment with HARVONI in a Phase 2 trial.
Genotype 4, 5 or 6
Resistance analysis was performed for 6 relapse subjects infected with HCV genotype 4 (Study 1119 and ION-4, N=3), genotype 5 (Study 1119, N=2) or genotype 6 (ELECTRON-2, N=1) and treated with HARVONI for 12 weeks. All the relapse subjects with NS5A sequencing data (5 of 6) had pretreatment NS5A resistance-associated polymorphisms (single or combinations at positions 24, 28, 30, 31, and 58). NS5A resistance substitutions (Y93C or L28V) emerged in two of the genotype 4 relapse subjects post-treatment who also had NS5A polymorphisms pretreatment that were retained post-treatment. Two of the relapsers with genotype 4 HCV infection had an NS5B V321I substitution pretreatment, which was retained post-treatment. Three of the relapse subjects (1 each for genotype 4, 5, and 6) had virus with emergent sofosbuvir resistance-associated substitution S282T at relapse; the genotype 5 relapse subject also had emergent nucleotide inhibitor substitution m289I.
Persistence Of Resistance-Associated Substitutions
No data are available on the persistence of ledipasvir or sofosbuvir resistance-associated substitutions. NS5A resistance-associated substitutions for other NS5A inhibitors have been found to persist for >1 year in some patients. The long-term clinical impact of the emergence or persistence of virus containing ledipasvir or sofosbuvir resistance-associated substitutions is unknown.
Effect Of Baseline HCV Polymorphisms On Treatment Response
Adults
Genotype 1
Analyses were conducted to explore the association between pre-existing baseline NS5A polymorphisms at resistance-associated positions and relapse rates. In the pooled analysis of the Phase 3 trials, 23% (370/1589) of subjects’ virus had baseline NS5A polymorphisms at resistance-associated positions (any change from reference at NS5A amino acid positions 24, 28, 30, 31, 58, 92, or 93) identified by population or analysis of deep nucleotide sequences with a 15% frequency threshold.
In treatment-naïve subjects whose virus had baseline NS5A polymorphisms at resistance-associated positions in Studies ION-1 and ION-3, relapse rates were 6% (3/48) after 8 weeks and 1% (1/113) after 12 weeks of treatment with HARVONI. Relapse rates among subjects without baseline NS5A polymorphisms at resistance-associated positions were 5% (8/167) after 8 weeks and 1% (3/306) after 12 weeks treatment with HARVONI.
In treatment-experienced subjects in Study ION-2 whose virus had baseline NS5A polymorphisms at resistance-associated positions, relapse rates were 22% (5/23) after 12 weeks and 0% (0/19) after 24 weeks of treatment with HARVONI. In another study in treatment-experienced subjects (SIRIUS), 0/15 (0%) subjects with NS5A polymorphisms at resistance-associated positions relapsed after 12 weeks of treatment with HARVONI + RBV compared to 2/15 (13%) subjects treated with 24 weeks of HARVONI.
SVR was achieved in all 24 subjects (N=20 with L159F+C316N; N=1 with L159F; and N=3 with N142T) who had baseline polymorphisms associated with resistance to sofosbuvir and/or other NS5B nucleoside inhibitors. The NS5B S282T substitution associated with resistance to sofosbuvir was not detected in the baseline NS5B sequence of any subject in Phase 3 trials by population or deep nucleotide sequence analysis.
In the SOLAR-1 and SOLAR-2 trials (liver transplant recipients or subjects with decompensated liver disease), after 12 weeks of treatment with HARVONI and RBV, relapse rates were 7% (5/71) and 5% (10/217) in genotype 1 subjects with and without baseline NS5A polymorphisms at resistance-associated positions, respectively.
In the Phase 3 trials and SOLAR trials, the specific baseline NS5A resistance-associated polymorphisms observed among subjects who relapsed were m28T/V, Q30H/R, L31M, H58D/P, and Y93H/N in genotype 1a, and L28M, L31M, A92T, and Y93H in genotype 1b. Subjects with multiple NS5A polymorphisms at resistance-associated positions appeared to have higher relapse rates.
Genotype 4, 5 or 6
Phylogenetic analysis of HCV sequences from genotype 4-infected subjects in Study 1119 (N=44) and ION-4 (N=8) identified 7 HCV genotype 4 subtypes (4a, 4b, 4d, 4f, 4m, 4o, and 4r). Most subjects were infected with subtype 4a (N=32; 62%) or 4d (N=11; 21%); 1 to 3 subjects were infected with each of the other genotype 4 subtypes. There were 3 subjects with subtype 4r, 2 of whom experienced virologic relapse, and both had a combination of 2 pretreatment NS5A resistance-associated polymorphisms (L28M/V+L30R).
Phylogenetic analysis of HCV sequences from genotype 5-infected subjects in Study 1119 showed almost all were subtype 5a (N=39) with one subject not having a subtype identified at screening or by analysis.
Phylogenetic analysis of HCV sequences from genotype 6-infected subjects in ELECTRON-2 identified 7 HCV genotype 6 subtypes (6a, 6e, 6l, 6m, 6p, 6q, and 6r). Thirty-two percent of the subjects had subtype 6a and 24% had subtype 6e. One to three subjects were infected with the other subtypes 6l, 6m, 6p, 6q, or 6r. The one subject who did not achieve SVR12 had subtype 6l.
Although the data are limited, baseline HCV NS5A resistance-associated polymorphisms are not expected to impact the likelihood of achieving SVR when HARVONI is used as recommended to treat HCV genotype 4, 5, or 6-infected patients, based on the low virologic failure rate observed in Study 1119 and ELECTRON-2. The specific baseline polymorphisms observed in subjects with virologic failure were L28M/V, L30R, and P58T for genotype 4; L31M for genotype 5; and Q24K, F28V, R30A, and T58P for genotype 6.
Relapse occurred in 2 of 3 genotype 4 subjects who had baseline NS5B V321I, a polymorphism at a position associated with treatment failure to sofosbuvir and other nucleoside inhibitors; these two subjects also had baseline NS5A resistance-associated polymorphisms. For genotype 5 and 6, SVR12 was achieved in subjects who had baseline NS5B polymorphisms at positions associated with resistance to sofosbuvir and other nucleoside inhibitors (N=1 with N142T in genotype 5; N=1 with m289I in genotype 5; N=15 with m289L/I in genotype 6). The sofosbuvir resistance-associated substitution S282T was not detected in the baseline NS5B sequence of any subject with genotype 4, 5, or 6 HCV in clinical trials by population or deep nucleotide sequence analysis.
Pediatrics
In Study 1116, the presence of NS5A and NS5B resistance-associated polymorphisms did not impact treatment outcome; all pediatric subjects 3 years of age and older with baseline NS5A or NS5B nucleoside inhibitor resistance-associated polymorphisms (14%; 32/223) achieved SVR following 12 weeks treatment with HARVONI.
Cross Resistance
Based on resistance patterns observed in cell culture replicon studies and HCV-infected subjects, cross-resistance between ledipasvir and other NS5A inhibitors is expected. Both sofosbuvir and ledipasvir were fully active against substitutions associated with resistance to other classes of direct-acting antivirals with different mechanisms of action, such as NS5B non-nucleoside inhibitors and NS3 protease inhibitors. The efficacy of ledipasvir/sofosbuvir has not been established in patients who have previously failed treatment with other regimens that include an NS5A inhibitor.
Clinical Studies
Description Of Clinical Trials
The efficacy and safety of HARVONI were evaluated in four trials in genotype 1 HCV mono-infected subjects including one trial exclusively in treatment-experienced subjects with compensated cirrhosis (Child-Pugh A), one trial in genotype 1 or 4 HCV/HIV-1 coinfected subjects, two trials in genotype 4, 5, or 6 HCV mono-infected subjects, two trials in genotype 1 or 4 HCV infected pretransplant subjects with decompensated cirrhosis (Child-Pugh B and C) or post-transplant with Metavir F0-F3 fibrosis, compensated cirrhosis, decompensated cirrhosis, or fibrosing cholestatic hepatitis (FCH), and one trial in genotype 1 or 4 HCV pediatric subjects 3 years of age and older without cirrhosis or with compensated cirrhosis, as summarized in Table 10 [see Clinical Trials In Subjects With Genotype 1 HCV, Clinical Trials In Subjects With Genotype 4, 5, Or 6 HCV, Clinical Trials In Subjects Coinfected With HCV And HIV-1, Clinical Trials In Liver Transplant Recipients And/Or Subjects With Decompensated Cirrhosis and Clinical Trial In Pediatric Subjects]:
Table 10 Trials Conducted with HARVONI with or without Ribavirin in Subjects with Chronic HCV Genotype 1, 4, 5, or 6 Infection
Trial |
Population |
Study Arms (Number of Subjects Treated) |
ION-3
(open-label) |
GT1, TN without cirrhosis |
HARVONI 8 weeks (215) |
HARVONI + RBV 8 weeks (216) |
HARVONI 12 weeks (216) |
ION-1
(open-label) |
GT1, TN with or without cirrhosis |
HARVONI 12 weeks (214) |
HARVONI + RBV 12 weeks (217) |
HARVONI 24 weeks (217) |
HARVONI + RBV 24 weeks (217) |
ION-2
(open-label) |
GT1, TE with or without cirrhosis |
HARVONI 12 weeks (109) |
HARVONI + RBV 12 weeks (111) |
HARVONI 24 weeks (109) |
HARVONI + RBV 24 weeks (111) |
SIRIUS
(double-blind) |
GT1, TE with cirrhosis |
HARVONI + RBV 12 Weeks (77) |
HARVONI 24 weeks (77) |
ION-4
(open-label) |
GT1 and GT4 HCV/HIV-1 coinfected TN and TE with or without cirrhosis |
HARVONI 12 Weeks (N=327 for GT1; N=8 for GT4) |
Study 1119
(open-label) |
GT4 and GT5, TN and TE with or without cirrhosis |
HARVONI 12 Weeks (N=44 for GT4; N=41 for GT5) |
ELECTRON-2
(open-label) |
GT6, TN and TE with or without cirrhosis |
HARVONI 12 Weeks (25) |
SOLAR-1 and SOLAR-2
(open-label) |
GT1 and GT4 pre-transplant with decompensated cirrhosis or post-transplant with Metavir F0-F3 fibrosis, compensated cirrhosis, decompensated cirrhosis, or FCH |
HARVONI + RBV 12 Weeks (336) |
HARVONI + RBV 24 weeks (334) |
1116
(open-label) |
GT1 or 4 TN and TE with or without cirrhosis in pediatric subjects 3 years of age and older |
HARVONI 12 Weeks (223) |
HARVONI 24 Weeks (1) |
TN: Treatment-naïve subjects
TE: Treatment-experienced subjects including those who have failed a peginterferon alfa + ribavirin based regimen with or without an HCV protease inhibitor. |
HARVONI was administered once daily by mouth in these trials. For subjects without cirrhosis or with compensated cirrhosis who received ribavirin (RBV), the RBV dosage was 1000 mg per day for subjects weighing less than 75 kg or 1200 mg per day for subjects weighing at least 75 kg. For subjects with decompensated cirrhosis in SOLAR1 and SOLAR-2 studies, the starting RBV dosage was 600 mg per day regardless of transplantation status. RBV dose adjustments were performed according to the RBV labeling.
Serum HCV RNA values were measured during the clinical trials using the COBAS TaqMan HCV test (version 2.0), for use with the High Pure System in ION-3, ION-1, ION-2, SIRIUS, and ION-4 studies or the COBAS AmpliPrep/COBAS Taqman HCV test (version 2.0) in ELECTRON-2, 1119, SOLAR-1, SOLAR-2, and 1116 studies. The COBAS TaqMan HCV test (version 2.0) for use with the High Pure System has a lower limit of quantification (LLOQ) of 25 IU per mL and the COBAS AmpliPrep/COBAS Taqman HCV test (version 2.0) has a 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 in studies in adults and the key efficacy endpoint in the study in pediatric subjects 12 years of age and older. Relapse was a secondary endpoint, which was defined as HCV RNA greater than or equal to LLOQ with 2 consecutive values or last available post-treatment measurement during the post-treatment period after achieving HCV RNA less than LLOQ at end of treatment.
Clinical Trials In Subjects With Genotype 1 HCV
Treatment-Naïve Adults Without Cirrhosis - ION-3 (Study 0108)
ION-3 was a randomized, open-label trial in treatment-naïve non-cirrhotic subjects with genotype 1 HCV. Subjects were randomized in a 1:1:1 ratio to one of the following three treatment groups and stratified by HCV genotype (1a vs 1b): HARVONI for 8 weeks, HARVONI for 12 weeks, or HARVONI + ribavirin for 8 weeks.
Demographics and baseline characteristics were balanced across the treatment groups. Of the 647 treated subjects, the median age was 55 years (range: 20 to 75); 58% of the subjects were male; 78% were White; 19% were Black; 6% were Hispanic or Latino; mean body mass index was 28 kg/m2 (range: 18 to 56 kg/m2); 81% had baseline HCV RNA levels greater than or equal to 800,000 IU per mL; 80% had genotype 1a HCV infection; 73% had non-C/C IL28B alleles (CT or TT).
Table 11 presents the SVR12 for the HARVONI treatment groups in the ION-3 trial after 8 and 12 weeks of HARVONI treatment. Ribavirin was not shown to increase the SVR12 observed with HARVONI. Therefore, the HARVONI + ribavirin arm is not presented in Table 11.
Table 11 - Study ION-3: SVR12 after 8 and 12 Weeks of Treatment in Treatment-Naïve Non-Cirrhotic Subjects with Genotype 1 HCV
|
HARVONI 8 Weeks (N=215) |
HARVONI 12 Weeks (N=216) |
SVR12 |
94% (202/215) |
96% (208/216) |
Outcome for Subjects without SVR |
On-Treatment Virologic Failure |
0/215 |
0/216 |
Relapsea |
5% (11/215) |
1% (3/216) |
Otherb |
1% (2/215) |
2% (5/216) |
SVR by Genotypec |
Genotype 1a |
93% (159/171) |
96% (165/172) |
Genotype 1b |
98% (42/43) |
98% (43/44) |
a.The denominator for relapse is the number of subjects with HCV RNA <LLOQ at their last on-treatment assessment.
b.Other includes subjects who did not achieve SVR and did not meet virologic failure criteria (e.g., lost to follow-up).
c.One subject without a confirmed subtype for genotype 1 infection was excluded from this subgroup analysis. |
The treatment difference between the 8-week treatment of HARVONI and 12-week treatment of HARVONI was –2.3% (97.5% confidence interval –7.2% to 2.5%). Among subjects with a baseline HCV RNA less than 6 million IU per mL, the SVR12 was 97% (119/123) with 8-week treatment of HARVONI and 96% (126/131) with 12-week treatment of HARVONI.
Relapse rates by baseline viral load are presented in Table 12.
Table 12 Study ION-3: Relapse Rates by Baseline Viral Load after 8 and
12 Weeks of Treatment in Treatment-Naïve Non-Cirrhotic Subjects
with Genotype 1 HCV
|
HARVONI 8 Weeks (N=215) |
HARVONI 12 Weeks (N=216) |
Number of Responders at End of Treatment |
215 |
216 |
Baseline HCV RNAa |
HCV RNA <6 million IU/mL |
2% (2/123) |
2% (2/131) |
HCV RNA ≥6 million IU/mL |
10% (9/92) |
1% (1/85) |
a. HCV RNA values were determined using the Roche TaqMan Assay; a subject’s HCV RNA may vary from visit to visit. |
Treatment-Naïve Adults With Or Without Cirrhosis - ION-1 (Study 0102)
ION-1 was a randomized, open-label trial that evaluated 12 and 24 weeks of treatment with HARVONI with or without ribavirin in 865 treatment-naïve subjects with genotype 1 HCV including those with cirrhosis. Subjects were randomized in a 1:1:1:1 ratio to receive HARVONI for 12 weeks, HARVONI + ribavirin for 12 weeks, HARVONI for 24 weeks, or HARVONI + ribavirin for 24 weeks. Randomization was stratified by the presence or absence of cirrhosis and HCV genotype (1a vs 1b).
Demographics and baseline characteristics were balanced across the treatment groups. Of the 865 treated subjects, the median age was 54 years (range: 18 to 80); 59% of the subjects were male; 85% were White; 12% were Black; 12% were Hispanic or Latino; mean body mass index was 27 kg/m2 (range: 18 to 48 kg/m2); 79% had baseline HCV RNA levels greater than or equal to 800,000 IU per mL; 67% had genotype 1a HCV infection; 70% had non-C/C IL28B alleles (CT or TT); and 16% had cirrhosis.
Table 13 presents the SVR12 for the treatment group of HARVONI for 12 weeks in the ION-1 trial. Ribavirin was not shown to increase SVR12 observed with HARVONI. Therefore, the HARVONI + ribavirin arm is not presented in Table 13.
Table 13 Study ION-1: SVR12 after 12 Weeks of Treatment in Treatment-Naïve Subjects with Genotype 1 HCV with and without Cirrhosis
|
HARVONI 12 Weeks (N=214) |
SVR12a |
99% (210/213) |
Outcome for Subjects without SVR |
On-Treatment Virologic Failurea |
0/213 |
Relapsea,b |
<1% (1/212) |
Othera,c |
1% (2/213) |
a.Excluding one subject with genotype 4 infection.
b.The denominator for relapse is the number of subjects with HCV RNA <LLOQ at their last on-treatment assessment.
c.Other includes subjects who did not achieve SVR12 and did not meet virologic failure criteria (e.g., lost to follow-up). |
SVR12 for selected subgroups are presented in Table 14.
Table 14 Study ION-1: SVR12 for Selected Subgroups after 12 Weeks of Treatment in Treatment-Naïve Subjects with Genotype 1 HCV with and without Cirrhosis
|
HARVONI 12 Weeks
(N=214) |
Genotypea |
Genotype 1a |
98% (142/145) |
Genotype 1b |
100% (67/67) |
Cirrhosisb |
No |
99% (176/177) |
Yes |
94% (32/34) |
a.One subject without a confirmed subtype for genotype 1 infection and one subject with genotype 4 infection were excluded from this subgroup analysis.
b.Subjects with missing cirrhosis status were excluded from this subgroup analysis. |
Previously-Treated Adults With Or Without Cirrhosis - ION-2 (Study 0109)
ION-2 was a randomized, open-label trial that evaluated 12 and 24 weeks of treatment with HARVONI with or without ribavirin in genotype 1 HCV-infected subjects with or without cirrhosis who failed prior therapy with an interferon-based regimen, including regimens containing an HCV protease inhibitor. Subjects were randomized in a 1:1:1:1 ratio to receive HARVONI for 12 weeks, HARVONI + ribavirin for 12 weeks, HARVONI for 24 weeks, or HARVONI + ribavirin for 24 weeks. Randomization was stratified by the presence or absence of cirrhosis, HCV genotype (1a vs 1b) and response to prior HCV therapy (relapse/breakthrough vs nonresponse).
Demographics and baseline characteristics were balanced across the treatment groups. Of the 440 treated subjects, the median age was 57 years (range: 24 to 75); 65% of the subjects were male; 81% were White; 18% were Black; 9% were Hispanic or Latino; mean body mass index was 28 kg/m2 (range: 19 to 50 kg/m2); 89% had baseline HCV RNA levels greater than or equal to 800,000 IU per mL; 79% had genotype 1a HCV infection; 88% had non-C/C IL28B alleles (CT or TT); and 20% had cirrhosis. Forty-seven percent (47%) of the subjects failed a prior therapy of pegylated interferon and ribavirin. Among these subjects, 49% were relapse/breakthrough and 51% were non-responder. Fifty-three percent (53%) of the subjects failed a prior therapy of pegylated interferon and ribavirin with an HCV protease inhibitor. Among these subjects, 62% were relapse/breakthrough and 38% were non-responder.
Table 15 presents the SVR12 for the HARVONI treatment groups in the ION-2 trial. Ribavirin was not shown to increase SVR12 observed with HARVONI. Therefore, the HARVONI + ribavirin arms are not presented in Table 15.
Table 15 Study ION-2: SVR12 after 12 and 24 Weeks of Treatment in Subjects
with Genotype 1 HCV with or without Cirrhosis Who Failed Prior
Therapy
|
HARVONI 12 Weeks (N=109) |
HARVONI 24 Weeks (N=109) |
SVR12 |
94% (102/109) |
99% (108/109) |
Outcome for Subjects without SVR |
On-Treatment Virologic Failure |
0/109 |
0/109 |
Relapsea |
6% (7/108) |
0/109 |
Otherb |
0/109 |
1% (1/109) |
a.The denominator for relapse is the number of subjects with HCV RNA <LLOQ at their last on-treatment assessment.
b.Other includes subjects who did not achieve SVR12 and did not meet virologic failure criteria (e.g., lost to follow-up). |
Among the subjects with available SVR12 and SVR24 data (206/218), all subjects who achieved SVR12 in the ION-2 study also achieved SVR24.
SVR12 and relapse rates for selected subgroups are presented in Tables 16 and 17.
Table 16 Study ION-2: SVR12 for Selected Subgroups after 12 and 24 Weeks of Treatment in Subjects with Genotype 1 HCV Who Failed Prior Therapy
|
HARVONI 12 Weeks (N=109) |
HARVONI 24 Weeks (N=109) |
Genotype |
Genotype 1a |
95% (82/86) |
99% (84/85) |
Genotype 1b |
87% (20/23) |
100% (24/24) |
Cirrhosisa |
No |
95% (83/87) |
99% (85/86) |
Yes |
86% (19/22) |
100% (22/22) |
Prior HCV Therapy |
Peg-IFN + RBV |
93% (40/43) |
100% (58/58) |
HCV protease inhibitor + Peg-IFN + RBV |
94% (62/66) |
98% (49/50) |
Response to Prior HCV Therapy |
Relapse/Breakthrough |
95% (57/60) |
100% (60/60) |
Non-responder |
92% (45/49) |
98% (48/49) |
a.Subjects with missing cirrhosis status were excluded from this subgroup analysis. |
Table 17 Study ION-2: Relapse Rates for Selected Subgroups after 12 and 24 Weeks of Treatment in Subjects with Genotype 1 HCV Who Failed Prior Therapy
|
HARVONI 12 Weeks (N=109) |
HARVONI 24 Weeks (N=109) |
Number of Responders at End of Treatment |
108 |
109 |
Cirrhosisa |
|
No |
5% (4/86)b |
0% (0/86) |
Yes |
14% (3/22) |
0% (0/22) |
Presence of Baseline NS5A Resistance-Associated Polymorphismsc |
No |
2% (2/85) |
0% (0/90) |
Yes |
22% (5/23) |
0% (0/19) |
IL28B Status |
|
|
C/C |
0% (0/10) |
0% (0/16) |
Non-C/C |
7% (7/98) |
0% (0/93) |
a.Subjects with missing cirrhosis status were excluded from this subgroup analysis.
b.These 4 non-cirrhotic relapsers all had baseline NS5A resistance-associated polymorphisms.
c.NS5A resistance-associated polymorphisms include any change at NS5A positions 24, 28, 30, 31, 58, 92, or 93. |
Previously-Treated Adults With Cirrhosis - SIRIUS (Study 0121)
SIRIUS was a randomized, double-blind and placebo-controlled trial that evaluated the efficacy of HARVONI + ribavirin for 12 weeks or HARVONI without ribavirin for 24 weeks in genotype 1 HCV-infected subjects with compensated cirrhosis who failed prior therapy with a Peg-IFN + RBV regimen followed by a subsequent Peg-IFN + RBV
+ an HCV protease inhibitor regimen. Subjects were randomized in a 1:1 ratio to receive placebo for 12 weeks followed by HARVONI + ribavirin for 12 weeks or HARVONI for 24 weeks. Randomization was stratified by HCV genotype (1a vs 1b) and response to prior HCV therapy (never achieved HCV RNA less than LLOQ vs achieved HCV RNA less than LLOQ).
Demographics and baseline characteristics were balanced across the treatment groups. Of the 155 randomized subjects, the median age was 56 years (range: 23 to 77); 74% of the subjects were male; 97% were White; mean body mass index was 27 kg/m2 (range: 19 to 47 kg/m2); 63% had genotype 1a HCV infection; 94% had non-C/C IL28B alleles (CT or TT). One subject discontinued therapy while on placebo, and was not included in the efficacy analysis.
The SVR12 was 96% (74/77) and 97% (75/77) in subjects treated with HARVONI + ribavirin for 12 weeks and HARVONI for 24 weeks without ribavirin, respectively. All 5 subjects who did not achieve SVR12 relapsed.
Clinical Trials In Subjects With Genotype 4, 5, Or 6 HCV
Below are trial descriptions, SVR12 and relapse data in the genotype 4, 5, and 6 HCV populations. Trial results in the genotype 4, 5, and 6 HCV populations are based upon limited number of subjects in some subgroups, particularly in subjects who have been previously-treated and subjects with cirrhosis.
Genotype 4
In two open-label studies (Study 1119 and ION-4), HARVONI was administered for 12 weeks to treatment-naïve and previously-treated adult subjects with genotype 4 HCV infection. Study 1119 enrolled 44 treatment-naïve or previously-treated subjects with genotype 4 HCV, with or without cirrhosis. ION-4 enrolled 4 treatment-naïve and 4 previously-treated subjects with genotype 4 HCV infection who were coinfected with HIV-1, none of whom had cirrhosis.
In Study 1119, the overall SVR12 rate was 93% (41/44). SVR12 was similar based upon prior HCV treatment history and cirrhosis status. In ION-4, all 8 subjects achieved SVR12.
Genotype 5
In the open-label 1119 trial, HARVONI was administered for 12 weeks to 41 treatmentnaïve or previously-treated adult subjects with genotype 5 HCV infection, with or without cirrhosis. The overall SVR12 was 93% (38/41). SVR12 was similar based upon prior HCV treatment history and cirrhosis status.
Genotype 6
In the open-label ELECTRON-2 trial, HARVONI was administered for 12 weeks to 25 treatment-naïve or previously-treated adult subjects with genotype 6 HCV infection, with or without cirrhosis. The overall SVR12 was 96% (24/25). SVR12 was similar based upon prior HCV treatment history and cirrhosis status. The single subject who relapsed discontinued study treatment early (at approximately Week 8).
Clinical Trials In Subjects Coinfected With HCV And HIV-1
ION-4 was an open-label clinical trial that evaluated the safety and efficacy of 12 weeks of treatment with HARVONI without ribavirin in HCV treatment-naïve and previously-treated adult subjects with genotype 1 or 4 HCV infection who were coinfected with HIV1.
Treatment-experienced subjects had failed prior treatment with Peg-IFN + RBV, Peg-IFN + RBV + an HCV protease inhibitor or sofosbuvir + RBV. Subjects were on a stable HIV-1 antiretroviral therapy that included emtricitabine + tenofovir disoproxil fumarate, administered with efavirenz, rilpivirine, or raltegravir.
Of the 335 treated subjects, the median age was 52 years (range: 26 to 72); 82% of the subjects were male; 61% were White; 34% were Black; mean body mass index was 27 kg/m2 (range: 18 to 66 kg/m2); 75% had genotype 1a HCV infection; 2% had genotype 4 infection; 76% had non-C/C IL28B alleles (CT or TT); and 20% had compensated cirrhosis. Fifty-five percent (55%) of the subjects were treatment-experienced.
Table 18 presents the SVR12 in the ION-4 trial after 12 weeks of HARVONI treatment.
Table 18 Study ION-4: SVR12 in Subjects with Genotype 1 or 4 HCV Coinfected with HIV-1
|
HARVONI 12 Weeks (N=335) |
SVR12 |
96% (321/335) |
Outcome for Subjects without SVR |
|
On-Treatment Virologic Failure |
<1% (2/335) |
Relapsea |
3% (10/333) |
Otherb |
<1% (2/335) |
a.The denominator for relapse is the number of subjects with HCV RNA <LLOQ at their last on-treatment assessment.
b.Other includes subjects who did not achieve SVR12 and did not meet virologic failure criteria (e.g., lost to follow-up). |
SVR12 rates were 94% (63/67) in subjects with cirrhosis and 98% (46/47) in subjects who were previously-treated and had cirrhosis. The relapse rate in the ION-4 trial in Black subjects was 9% (10/115), all of whom were IL28B non-CC genotype, and none in non-Black subjects (0/220). In the ION-1, ION-2, and ION-3 HCV mono-infection studies, relapse rates were 3% (10/305) in Black subjects and 2% (26/1637) in non-Black subjects.
No subject had HIV-1 rebound during the study. The percentage of CD4+ cells did not change during treatment. Median CD4+ cell count increase of 29 cells/mm3 was observed at the end of treatment with HARVONI for 12 weeks.
Clinical Trials In Liver Transplant Recipients And/Or Subjects With Decompensated Cirrhosis
SOLAR-1 and SOLAR-2 were two open-label trials that evaluated 12 and 24 weeks of treatment with HARVONI in combination with ribavirin in HCV treatment-naïve and previously-treated adult subjects with genotype 1 and 4 infection who had undergone liver transplantation and/or who had decompensated liver disease. The two trials were identical in study design. Subjects were enrolled in one of the seven groups in the trials based on liver transplantation status and severity of hepatic impairment (see Table 19). Subjects with a CPT score greater than 12 were excluded. Within each group, subjects were randomized in a 1:1 ratio to receive HARVONI + RBV for 12 weeks or HARVONI + RBV for 24 weeks. For subjects with decompensated cirrhosis in SOLAR-1 and SOLAR-2 studies, the starting RBV dosage was 600 mg per day regardless of transplantation status. RBV dose adjustments were performed according to the RBV labeling [see Description Of Clinical Trials].
Demographics and baseline characteristics were balanced across the treatment groups. Of the 670 treated subjects, the median age was 59 years (range: 21 to 81); 77% of the subjects were male; 91% were White; mean body mass index was 28 kg/m2 (range: 18 to 49 kg/m2); 94% and 6% had genotype 1 and 4 HCV infection, respectively; 78% of the subjects failed a prior HCV therapy.
Table 19 presents the pooled SVR12 rates for SOLAR-1 and SOLAR-2 in subjects with genotype 1 HCV treated with HARVONI + RBV for 12 weeks. The SVR12 rates observed with 24 weeks of HARVONI + RBV were similar to the SVR12 rates observed with 12 weeks of treatment. Therefore, the results for the HARVONI + RBV 24 weeks arm are not presented in Table 19.
Table 19 Studies SOLAR-1 and SOLAR-2: SVR12 and Relapse Rates After 12 Weeks of Treatment with HARVONI and Ribavirin in Subjects with Genotype 1 HCV Who Were Post Liver Transplant and/or Who Had Decompensated Liver Disease
|
HARVONI + RBV 12 weeks (N=307) |
SVR12 (N=300)a,b |
Relapse (N=288)a,b,c |
Pre-transplant |
CPT B |
87% (45/52) |
12% (6/51) |
CPT C |
88% (35/40) |
5% (2/37) |
Post-transplant |
Metavir score F0-F3 |
95% (94/99) |
3% (3/97) |
CPT A |
98% (55/56) |
0% (0/55) |
CPT B |
89% (41/46) |
2% (1/42) |
CPT C |
57% (4/7) |
33% (2/6) |
a.Five subjects transplanted prior to post-treatment Week 12 with HCV RNA<LLOQ at last measurement prior to transplant were excluded.
b.Two subjects were excluded due to failure to meet the inclusion criteria for any of the treatment groups (i.e., did not have decompensated cirrhosis and had also not received a liver transplant).
c.Twelve subjects were excluded from relapse analysis because they died (N=11) or withdrew consent (N=1) prior to reaching the 12 week post-treatment follow-up visit. |
There were 7 subjects with fibrosing cholestatic hepatitis in the 12 week treatment arm, and all subjects achieved SVR12.
In genotype 4 HCV post-transplant subjects without cirrhosis or with compensated cirrhosis treated with HARVONI + RBV for 12 weeks (N=12), the SVR12 rate was similar to rates reported with genotype 1; no subjects relapsed. Available data in subjects with genotype 4 HCV who had decompensated cirrhosis (pre- and post-liver transplantation) were insufficient for dosing recommendations; therefore, these results are not presented.
Clinical Trial In Pediatric Subjects
The efficacy of HARVONI was evaluated in an open-label trial (Study 1116) in 224 HCV treatment-naïve (N=186) and treatment-experienced (N=38) pediatric subjects 3 years of age or older. This study evaluated 12 weeks of treatment with HARVONI once daily in genotype 1 (N=183) or genotype 4 (N=3) treatment-naive subjects without cirrhosis or with compensated cirrhosis; genotype 1 treatment-experienced subjects without cirrhosis (N=37); and evaluated 24 weeks of treatment with HARVONI once daily in one genotype 1 subject who was both treatment-experienced and cirrhotic.
Subjects 12 Years To <18 Years Of Age
HARVONI was evaluated in 100 subjects 12 years to <18 years of age with HCV genotype 1 infection. Demographics and baseline characteristics were balanced across treatment-naïve and treatment-experienced subjects (patients had failed an interferon based regimen with or without ribavirin). The median age was 15 years (range: 12 to 17); 63% of the subjects were female; 91% were White, 7% were Black, and 2% were Asian; 13% were Hispanic/Latino; mean body mass index was 23 kg/m2 (range: 13.1 to 36.6 kg/m2); mean weight was 61 kg (range 33 to 126 kg); 55% had baseline HCV RNA levels greater than or equal to 800,000 IU/mL; 81% had genotype 1a HCV infection. One subject (treatment-naïve) had known compensated cirrhosis. The majority of subjects (84%) had been infected through vertical transmission.
The SVR12 rate was 98% overall (98% [78/80] in treatment-naïve subjects and 100% [20/20] in treatment-experienced subjects). No subject experienced on-treatment virologic failure or relapse. Two subjects were lost to follow-up.
Subjects 6 Years To <12 Years Of Age
HARVONI was evaluated in 90 subjects 6 years to <12 years of age with HCV genotype 1 or 4 infection. Among these subjects, 72 (80%) were treatment-naïve and 18 (20%) were treatment-experienced. Eighty-nine of the subjects (87 with genotype 1 HCV infection and 2 with genotype 4 HCV infection) were treated with HARVONI for 12 weeks, 1 subject with genotype 1 HCV infection was treated with HARVONI for 24 weeks. The median age was 9 years (range: 6 to 11); 59% of the subjects were male; 79% were White, 8% were Black, and 6% were Asian; 10% were Hispanic/Latino; mean body mass index was 18 kg/m2 (range: 13 to 31kg/m2); mean weight was 33 kg (range 18 to 76 kg); 59% had baseline HCV RNA levels greater than or equal to 800,000 IU/mL; 86% had genotype 1a HCV infection; 2 subjects (1 treatment-naïve, 1 treatment-experienced) had known compensated cirrhosis. The majority of subjects (97%) had been infected through vertical transmission.
The SVR12 rate was 99% (86/87) in subjects with genotype 1 HCV infection, and 100% (2/2) in subjects with genotype 4 HCV infection. The one genotype 1 subject treated with HARVONI for 24 weeks also achieved SVR12. The one subject (genotype 1) who did not achieve SVR12 and relapsed had been treated with HARVONI for 12 weeks.
Subjects 3 Years To <6 Years Of Age
HARVONI was evaluated in 34 subjects 3 years to <6 years of age with HCV genotype 1 (N = 33) or genotype 4 (N = 1) infection. All of the subjects were treatment-naïve and treated with HARVONI for 12 weeks. The median age was 5 years (range: 3 to 5); 71% of the subjects were female; 79% were White, 3% were Black, and 6% were Asian; 18% were Hispanic/Latino; mean body mass index was 17 kg/m2 (range: 13 to 25 kg/m2); mean weight was 19 kg (range 11 to 34 kg); 56% had baseline HCV RNA levels greater than or equal to 800,000 IU/mL; 82% had genotype 1a HCV infection; no subjects had known cirrhosis. All subjects (100%) had been infected through vertical transmission.
The SVR12 rate was 97% (32/33) in subjects with genotype 1 HCV infection, and the one subject with genotype 4 HCV infection also achieved SVR12. One subject prematurely discontinued study treatment due to an adverse event.