CLINICAL PHARMACOLOGY
Mechanism Of Action
ZEPATIER is a fixed-dose
combination of elbasvir and grazoprevir which are direct-acting antiviral agents
against the hepatitis C virus [see Microbiology].
Pharmacodynamics
Cardiac Electrophysiology
Thorough QT studies have been
conducted for elbasvir and grazoprevir.
The effect of elbasvir 700 mg
on QTc interval was evaluated in a randomized, single-dose, placeboand active-controlled
(moxifloxacin 400 mg) 3-period crossover thorough QT trial in 42 healthy
subjects. At a concentration 3 to 4 times the
therapeutic concentration, elbasvir does not prolong QTc to any clinically relevant
extent.
The effect of grazoprevir
1600 mg (16 times the approved dose) on QTc interval was evaluated in a randomized,
single-dose, placebo- and active-controlled (moxifloxacin 400 mg) 3-period
crossover thorough QT trial in 41 healthy subjects. At a concentration 40 times the therapeutic concentration, grazoprevir
does not prolong QTc to any clinically relevant extent.
Pharmacokinetics
The pharmacokinetic properties
of elbasvir and grazoprevir have been evaluated in non-HCVinfected adult
subjects and in HCV-infected adult subjects. Elbasvir pharmacokinetics were
similar in healthy subjects and HCV-infected subjects and were approximately
dose-proportional over the range of 5-100 mg once daily. Grazoprevir oral
exposures are approximately 2-fold greater in HCV-infected subjects as compared
to healthy subjects. Grazoprevir pharmacokinetics increased in a greater than
doseproportional manner over the range of 10-800 mg once daily in HCV-infected
subjects. Ribavirin coadministration with ZEPATIER had no clinically relevant
impact on plasma AUC and Cmax of elbasvir and grazoprevir compared to
administration of ZEPATIER alone. The geometric mean steady-state pharmacokinetic
parameter values for elbasvir and grazoprevir in non-cirrhotic HCV-infected
subjects are provided in Table 7. Following once daily administration of
ZEPATIER to HCV-infected subjects, elbasvir and grazoprevir reached steady
state within approximately 6 days.
Table 7: Geometric Mean (90%
Confidence Interval) for Elbasvir and Grazoprevir Steady State Pharmacokinetic
Parameter Values in Non-Cirrhotic HCV-Infected Subjects Estimated Based on Population
Pharmacokinetic Modeling
|
Geometric Mean (90% Confidence Interval) |
AUC0-24 (ng•hr/mL) |
Cmax (ng/mL) |
C24 (ng/mL) |
Elbasvir |
1920 (1880, 1960) |
121 (118, 123) |
48.4 (47.3, 49.6) |
Grazoprevir |
1420 (1400, 1530) |
165 (161, 176) |
18.0 (17.8, 19.9) |
Absorption
Following administration of ZEPATIER to HCV-infected
subjects, elbasvir peak concentrations occur at a median Tmax of 3 hours (range
of 3 to 6 hours); grazoprevir peak concentrations occur at a median Tmax of 2
hours (range of 30 minutes to 3 hours). The absolute bioavailability of elbasvir
is estimated to be 32%, and grazoprevir is estimated to be 27%.
Effect Of Food
Relative to fasting conditions, the administration of a
single dose of ZEPATIER with a high-fat (900 kcal, 500 kcal from fat) meal to
healthy subjects resulted in decreases in elbasvir AUC0-inf and Cmax of approximately
11% and 15%, respectively, and increases in grazoprevir AUC0-inf and Cmax of
approximately 1.5-fold and 2.8-fold, respectively. These differences in
elbasvir and grazoprevir exposure are not clinically relevant; therefore,
ZEPATIER may be taken without regard to food [see DOSAGE AND ADMINISTRATION].
Distribution
Elbasvir and grazoprevir are extensively bound (greater
than 99.9% and 98.8%, respectively) to human plasma proteins. Both elbasvir and
grazoprevir bind to human serum albumin and α1-acid glycoprotein.
Estimated apparent volume of distribution values of elbasvir and grazoprevir
are approximately 680 L and 1250 L, respectively, based on population
pharmacokinetic modeling.
In preclinical distribution studies, elbasvir distributes
into most tissues including the liver; whereas grazoprevir distributes
predominantly to the liver likely facilitated by the active transport through
the OATP1B1/3 liver uptake transporter.
Elimination
The geometric mean apparent terminal half-life for elbasvir
(50 mg) and grazoprevir (100 mg) is approximately 24 and 31 hours,
respectively, in HCV-infected subjects.
Metabolism
Elbasvir and grazoprevir are partially eliminated by
oxidative metabolism, primarily by CYP3A. No circulating metabolites of either
elbasvir or grazoprevir were detected in human plasma.
Excretion
The primary route of elimination of elbasvir and
grazoprevir is through feces with almost all (greater than 90%) of radiolabeled
dose recovered in feces compared to less than 1% in urine.
Specific Populations
Pediatric Population
The pharmacokinetics of ZEPATIER in pediatric patients
less than 18 years of age have not been established.
Geriatric Population
In population pharmacokinetic analyses, elbasvir and
grazoprevir AUCs are estimated to be 16% and 45% higher, respectively, in
subjects at least 65 years of age compared to subjects less than 65 years of age.
Gender
In population pharmacokinetic analyses, elbasvir and
grazoprevir AUCs are estimated to be 50% and 30% higher, respectively, in females
compared to males.
Weight/BMI
In population pharmacokinetic analyses, there was no
effect of weight on elbasvir pharmacokinetics. Grazoprevir AUC is estimated to
be 15% higher in a 53-kg subject compared to a 77-kg subject. This change is
not clinically relevant for grazoprevir.
Race/Ethnicity
In population pharmacokinetic analyses, elbasvir and
grazoprevir AUCs are estimated to be 15% and 50% higher, respectively, for
Asians compared to Caucasians. Population pharmacokinetics estimates of exposure
of elbasvir and grazoprevir were comparable between Caucasians and
Black/African Americans.
Renal Impairment
In population pharmacokinetic analyses, elbasvir AUC was
25% higher in hemodialysis-dependent subjects and 46% higher in
non-dialysis-dependent subjects with severe renal impairment compared to elbasvir
AUC in subjects without severe renal impairment. In population pharmacokinetic
analysis in HCVinfected subjects, grazoprevir AUC was 10% higher in
hemodialysis-dependent subjects and 40% higher in non-dialysis-dependent
subjects with severe renal impairment compared to grazoprevir AUC in subjects without
severe renal impairment. Elbasvir and grazoprevir are not removed by
hemodialysis. Elbasvir and grazoprevir are unlikely to be removed by peritoneal
dialysis as both are highly protein bound.
Overall, changes in exposure of elbasvir and grazoprevir
in HCV-infected subjects with renal impairment with or without hemodialysis are
not clinically relevant [see Use In Specific Populations].
Hepatic Impairment
The pharmacokinetics of elbasvir and grazoprevir were
evaluated in non-HCV-infected subjects with mild hepatic impairment (Child-Pugh
Category A [CP-A], score of 5-6), moderate hepatic impairment (Child- Pugh
Category B [CP-B], score of 7-9) and severe hepatic impairment (Child-Pugh
Category C [CP-C], score of 10-15). In addition, the pharmacokinetics of
elbasvir and grazoprevir were also evaluated in HCVinfected subjects including
CP-A subjects with compensated cirrhosis.
Relative to non-HCV-infected subjects with normal hepatic
function, no clinically relevant differences in elbasvir AUC values were
observed in non-HCV-infected subjects with mild, moderate, or severe hepatic impairment.
In population pharmacokinetic analyses, elbasvir steady-state AUC was similar
in HCVinfected subjects with compensated cirrhosis compared to HCV-infected,
non-cirrhotic subjects.
Relative to non-HCV-infected subjects with normal hepatic
function, grazoprevir AUC values were higher by 1.7-fold, 5-fold, and 12-fold
in non-HCV-infected subjects with mild, moderate, and severe hepatic impairment,
respectively. In population pharmacokinetic analyses, grazoprevir steady-state
AUC values were higher by 1.65-fold in HCV-infected subjects with compensated
cirrhosis compared to HCV-infected, non-cirrhotic subjects.
Drug Interaction Studies
Drug interaction studies were performed in healthy adults
with elbasvir, grazoprevir, or coadministered elbasvir and grazoprevir and
drugs likely to be co-administered or drugs commonly used as probes for
pharmacokinetic interactions. Table 8 summarizes the effects of co-administered
drugs on the exposures of the individual components of ZEPATIER (elbasvir and
grazoprevir). Table 9 summarizes the effects of the individual components of
ZEPATIER on the exposures of the co-administered drugs. For information
regarding clinical recommendations, [see CONTRAINDICATIONS, WARNINGS
AND PRECAUTIONS, and DRUG INTERACTIONS].
Elbasvir and grazoprevir are substrates of CYP3A and
P-gp, but the role of intestinal P-gp in the absorption of elbasvir and
grazoprevir appears to be minimal. Co-administration of moderate and strong CYP3A
inducers with ZEPATIER may decrease elbasvir and grazoprevir plasma
concentrations, leading to reduced therapeutic effect of ZEPATIER.
Co-administration of strong CYP3A4 inhibitors with ZEPATIER may increase
elbasvir and grazoprevir plasma concentrations.
Grazoprevir is a substrate of OATP1B1/3.
Co-administration of ZEPATIER with drugs that inhibit OATP1B1/3 transporters may
result in a clinically relevant increase in grazoprevir plasma concentrations.
Elbasvir is not a CYP3A inhibitor in vitro and
grazoprevir is a weak CYP3A inhibitor in humans. Coadministration with
grazoprevir resulted in a 34% increase in plasma exposure of midazolam and a
43% increase in plasma exposure of tacrolimus (see Tables 6 and 9). Elbasvir
inhibited P-gp in vitro, but no clinically relevant increases in concentrations
of digoxin (a P-gp substrate; see Table 9) were observed by co-administration of
elbasvir. Grazoprevir is not a P-gp inhibitor in vitro. Elbasvir and
grazoprevir are inhibitors of the drug transporter breast cancer resistance
protein (BCRP) at the intestinal level in humans and may increase plasma
concentrations of co-administered BCRP substrates.
Clinically significant drug interactions with ZEPATIER as
an inhibitor of other CYP enzymes (CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, and
CYP2D6), UGT1A1, esterases (CES1, CES2, and CatA), organic anion transporters
(OAT)1 and OAT3, and organic cation transporter (OCT)2, are not expected, and
multiple-dose administration of elbasvir or grazoprevir is unlikely to induce
the metabolism of drugs metabolized by CYP1A2, CYP2B6, or CYP3A based on in
vitro data.
Table 8: Drug Interactions: Changes in
Pharmacokinetics of Elbasvir or Grazoprevir in the Presence of Co-Administered
Drug
Co- Administered Drug |
Regimen of CoAdministered Drug |
Regimen of EBR or/and GZR |
N |
Geometric Mean Ratio [90% CI] of EBR and GZR PK with/without Co-Administered Drug (No Effect=1.00) |
|
AUC* |
Cmax |
C24 |
Antifungal |
Ketoconazole |
400 mg once daily |
EBR 50 mg single-dose |
7 |
EBR |
1.80 (1.41, 2.29) |
1.29 (1.00, 1.66) |
1.89 (1.37, 2.60) |
400 mg once daily |
GZR 100 mg single-dose |
8 |
GZR |
3.02 (2.42, 3.76) |
1.13 (0.77, 1.67) |
2.01 (1.49, 2.71) |
Antimycobacterial |
Rifampin |
600 mg singledose IV |
EBR 50 mg single-dose |
14 |
EBR |
1.22 (1.06, 1.40) |
1.41 (1.18, 1.68) |
1.31 (1.12, 1.53) |
600 mg singledose PO |
EBR 50 mg single-dose |
14 |
EBR |
1.17 (0.98, 1.39) |
1.29 (1.06, 1.58) |
1.21 (1.03, 1.43) |
600 mg PO once daily |
GZR 200 mg once daily |
12 |
GZR |
0.93 (0.75, 1.17) |
1.16 (0.82, 1.65) |
0.10 (0.07, 0.13) |
600 mg IV single-dose |
GZR 200 mg single-dose |
12 |
GZR |
10.21 (8.68, 12.00) |
10.94 (8.92, 13.43) |
1.77 (1.40, 2.24) |
600 mg PO single-dose |
GZR 200 mg once daily |
12 |
GZR |
8.35 (7.38, 9.45)† |
6.52 (5.16, 8.24) |
1.62 (1.32, 1.98) |
HCV Antiviral |
EBR |
20 mg once daily |
GZR 200 mg once daily |
10 |
GZR |
0.90 (0.63, 1.28) |
0.87 (0.50, 1.52) |
0.94 (0.77, 1.15) |
GZR |
200 mg once daily |
EBR 20 mg once daily |
10 |
EBR |
1.01 (0.83, 1.24) |
0.93 (0.76, 1.13) |
1.02 (0.83, 1.24) |
HIV Protease Inhibitor |
Atazanavir/ ritonavir |
300 mg/ 100 mg once daily |
EBR 50 mg once daily |
10 |
EBR |
4.76 (4.07, 5.56) |
4.15 (3.46, 4.97) |
6.45 (5.51, 7.54) |
300 mg/ 100 mg once daily |
GZR 200 mg once daily |
12 |
GZR |
10.58 (7.78, 14.39) |
6.24 (4.42, 8.81) |
11.64 (7.96, 17.02) |
Darunavir/ ritonavir |
600 mg/ 100 mg twice daily |
EBR 50 mg once daily |
10 |
EBR |
1.66 (1.35, 2.05) |
1.67 (1.36, 2.05) |
1.82 (1.39, 2.39) |
600 mg/ 100 mg twice daily |
GZR 200 mg once daily |
13 |
GZR |
7.50 (5.92, 9.51) |
5.27 (4.04, 6.86) |
8.05 (6.33, 10.24) |
Lopinavir/ ritonavir |
400 mg/ 100 mg twice daily |
EBR 50 mg once daily |
10 |
EBR |
3.71 (3.05, 4.53) |
2.87 (2.29, 3.58) |
4.58 (3.72, 5.64) |
400 mg/ 100 mg twice daily |
GZR 200 mg once daily |
13 |
GZR |
12.86 (10.25, 16.13) |
7.31 (5.65, 9.45) |
21.70 (12.99, 36.25) |
Ritonavir‡ |
100 mg twice daily |
GZR 200 mg single-dose |
10 |
GZR |
2.03 (1.60, 2.56) |
1.15 (0.60, 2.18) |
1.88 (1.65, 2.14) |
HIV Integrase Strand Transfer Inhibitor |
Dolutegravir |
50 mg singledose |
EBR 50 mg + GZR 200 mg once daily |
12 |
EBR |
0.98 (0.93, 1.04) |
0.97 (0.89, 1.05) |
0.98 (0.93, 1.03) |
50 mg singledose |
EBR 50 mg + GZR 200 mg once daily |
12 |
GZR |
0.81 (0.67, 0.97) |
0.64 (0.44, 0.93) |
0.86 (0.79, 0.93) |
Raltegravir |
400 mg singledose |
EBR 50 mg single-dose |
10 |
EBR |
0.81 (0.57, 1.17) |
0.89 (0.61, 1.29) |
0.80 (0.55, 1.16) |
400 mg twice daily |
GZR 200 mg once daily |
11 |
GZR |
0.89 (0.72, 1.09) |
0.85 (0.62, 1.16) |
0.90 (0.82, 0.99) |
HIV Non-Nucleoside Reverse Transcriptase Inhibitor |
Efavirenz |
600 mg once daily |
EBR 50 mg once daily |
10 |
EBR |
0.46 (0.36, 0.59) |
0.55 (0.41, 0.73) |
0.41 (0.28, 0.59) |
600 mg once daily |
GZR 200 mg once daily |
12 |
GZR |
0.17 (0.13, 0.24) |
0.13 (0.09, 0.19) |
0.31 (0.25, 0.38) |
Rilpivirine |
25 mg once daily |
EBR 50 mg + GZR 200 mg once daily |
19 |
EBR |
1.07 (1.00, 1.15) |
1.07 (0.99, 1.16) |
1.04 (0.98, 1.11) |
25 mg once daily |
EBR 50 mg + GZR 200 mg once daily |
19 |
GZR |
0.98 (0.89, 1.07) |
0.97 (0.83, 1.14) |
1.00 (0.93, 1.07) |
HIV Nucleotide Reverse Transcriptase Inhibitor |
Tenofovir disoproxil fumarate |
300 mg once daily |
EBR 50 mg once daily |
10 |
EBR |
0.93 (0.82, 1.05) |
0.88 (0.77, 1.00) |
0.92 (0.81, 1.05) |
300 mg once daily |
GZR 200 mg once daily |
12 |
GZR |
0.86 (0.65, 1.12) |
0.78 (0.51, 1.18) |
0.89 (0.78, 1.01) |
HIV Fixed-Dose Combination Regimen |
Elvitegravir/ cobicistat/ emtricitabine/ tenofovir disoproxil fumarate |
150 mg/ 150 mg/ 200 mg/ 300 mg once daily |
EBR 50 mg/ GZR 100 mg once daily |
21 |
EBR |
2.18 (2.02, 2.35) |
1.91 (1.77, 2.05) |
2.38 (2.19, 2.60) |
EBR 50 mg/ GZR 100 mg once daily |
21 |
GZR |
5.36 (4.48, 6.43) |
4.59 (3.70, 5.69) |
2.78 (2.48, 3.11) |
Immunosuppressant |
Cyclosporine |
400 mg singledose |
EBR 50 mg + GZR 200 mg once daily |
14 |
EBR |
1.98 (1.84, 2.13) |
1.95 (1.84, 2.07) |
2.21 (1.98, 2.47) |
400 mg singledose |
EBR 50 mg + GZR 200 mg once daily |
14 |
GZR |
15.21 (12.83, 18.04) |
17.00 (12.94, 22.34) |
3.39 (2.82, 4.09) |
Mycophenolate mofetil |
1000 mg single-dose |
EBR 50 mg + GZR 200 mg once daily |
14 |
EBR |
1.07 (1.00, 1.14) |
1.07 (0.98, 1.16) |
1.05 (0.97, 1.14) |
|
1000 mg single-dose |
EBR 50 mg + GZR 200 mg once daily |
14 |
GZR |
0.74 (0.60, 0.92) |
0.58 (0.42, 0.82) |
0.97 (0.89, 1.06) |
Prednisone |
40 mg singledose |
EBR 50 mg + GZR 200 mg once daily |
14 |
EBR |
1.17 (1.11, 1.24) |
1.25 (1.16, 1.35) |
1.04 (0.97, 1.12) |
40 mg singledose |
EBR 50 mg + GZR 200 mg once daily |
14 |
GZR |
1.09 (0.95, 1.25) |
1.34 (1.10, 1.62) |
0.93 (0.87, 1.00) |
Tacrolimus |
2 mg singledose |
EBR 50 mg + GZR 200 mg once daily |
16 |
EBR |
0.97 (0.90, 1.06) |
0.99 (0.88, 1.10) |
0.92 (0.83, 1.02) |
2 mg singledose |
EBR 50 mg + GZR 200 mg once daily |
16 |
GZR |
1.12 (0.97, 1.30) |
1.07 (0.83, 1.37) |
0.94 (0.87, 1.02) |
Opioid-Substitution Therapy |
Buprenorphine /naloxone |
8 mg/2 mg single-dose |
EBR 50 mg single-dose |
15 |
EBR |
1.22 (0.98, 1.52) |
1.13 (0.87, 1.46) |
1.22 (0.99, 1.51) |
8-24 mg/ 2-6 mg once daily |
GZR 200 mg once daily |
12§ |
GZR |
0.86 (0.63, 1.18) |
0.80 (0.54, 1.20) |
0.97 (0.77, 1.22) |
Methadone |
20-120 mg once daily |
EBR 50 mg once daily |
10§ |
EBR |
1.20 (0.94, 1.53) |
1.23 (0.94, 1.62) |
1.32 (1.03, 1.68) |
20-150 mg once daily |
GZR 200 mg once daily |
12§ |
GZR |
1.03 (0.76, 1.41) |
0.89 (0.60, 1.32) |
0.98 (0.79, 1.23) |
Acid-Reducing Agent |
Famotidine |
20 mg singledose |
EBR 50 mg/ GZR 100 mg single-dose |
16 |
EBR |
1.05 (0.92, 1.18) |
1.11 (0.98, 1.26) |
1.03 (0.91, 1.17) |
20 mg singledose |
EBR 50 mg/ GZR 100 mg single-dose |
16 |
GZR |
1.10 (0.95, 1.28) |
0.89 (0.71, 1.11) |
1.12 (0.97, 1.30) |
Pantoprazole |
40 mg once daily |
EBR 50 mg/ GZR 100 mg single-dose |
16 |
EBR |
1.05 (0.93, 1.18) |
1.02 (0.92, 1.14) |
1.03 (0.92, 1.17) |
40 mg once daily |
EBR 50 mg/ GZR 100 mg single-dose |
16 |
GZR |
1.12 (0.96, 1.30) |
1.10 (0.89, 1.37) |
1.17 (1.02, 1.34) |
Phosphate Binder |
Calcium acetate |
2668 mg single-dose |
EBR 50 mg + GZR 100 mg single-dose |
12 |
EBR |
0.92 (0.75, 1.14) |
0.86 (0.71, 1.04) |
0.87 (0.70, 1.09) |
2668 mg single-dose |
EBR 50 mg + GZR 100 mg single-dose |
12 |
GZR |
0.79 (0.68, 0.91) |
0.57 (0.40, 0.83) |
0.77 (0.61, 0.99) |
Sevelamer carbonate |
2400 mg single-dose |
EBR 50 mg + GZR 100 mg single-dose |
12 |
EBR |
1.13 (0.94, 1.37) |
1.07 (0.88, 1.29) |
1.22 (1.02, 1.45) |
2400 mg single-dose |
EBR 50 mg + GZR 100 mg single-dose |
12 |
GZR |
0.82 (0.68, 0.99) |
0.53 (0.37, 0.76) |
0.84 (0.71, 0.99) |
Statin |
Atorvastatin |
20 mg singledose |
GZR 200 mg once daily |
9 |
GZR |
1.26 (0.97, 1.64) |
1.26 (0.83, 1.90) |
1.11 (1.00, 1.23) |
Pitavastatin |
1 mg singledose |
GZR 200 mg once daily |
9 |
GZR |
0.81 (0.70, 0.95) |
0.72 (0.57, 0.92) |
0.91 (0.82, 1.01) |
Pravastatin |
40 mg singledose |
EBR 50 mg + GZR 200 mg once daily |
12 |
EBR |
0.98 (0.93, 1.02) |
0.97 (0.89, 1.05) |
0.97 (0.92, 1.02) |
40 mg singledose |
EBR 50 mg + GZR 200 mg once daily |
12 |
GZR |
1.24 (1.00, 1.53) |
1.42 (1.00, 2.03) |
1.07 (0.99, 1.16) |
Rosuvastatin |
10 mg singledose |
EBR 50 mg + GZR 200 mg single-dose |
11 |
EBR |
1.09 (0.98, 1.21) |
1.11 (0.99, 1.26) |
0.96 (0.86, 1.08) |
10 mg singledose |
GZR 200 mg once daily |
11 |
GZR |
1.16 (0.94, 1.44) |
1.13 (0.77, 1.65) |
0.93 (0.84, 1.03) |
10 mg singledose |
EBR 50 mg + GZR 200 mg once daily |
11 |
GZR |
1.01 (0.79, 1.28) |
0.97 (0.63, 1.50) |
0.95 (0.87, 1.04) |
Abbreviations: EBR, elbasvir; GZR, grazoprevir; IV,
intravenous; PO, oral; EBR + GZR, administration of EBR and GZR as separate
pills; EBR/GZR, administration of EBR and GZR as a single fixed-dose
combination tablet.
*AUC0-inf for single-dose, AUC0-24 for once daily.
†AUC0-24
‡Higher doses of ritonavir have not been tested in a drug interaction study
with GZR.
§The reference (EBR or GZR alone) for the analysis consisted of subjects pooled
across Phase I studies. |
Table 9: Drug Interactions: Changes in
Pharmacokinetics for Co-Administered Drug in the Presence of Elbasvir,
Grazoprevir, or Co-Administered Elbasvir and Grazoprevir
Co- Administered Drug |
Regimen of CoAdministered Drug |
EBR or/and GZR Administration |
EBR or/and GZR Regimen |
N |
Geometric Mean Ratio [90% CI] of CoAdministered Drug PK with/without EBR or/and GZR (No Effect=1.00) |
AUC* |
Cmax |
Ctrough† |
P-gp Substrate |
Digoxin |
Digoxin 0.25 mg single-dose |
EBR |
50 mg once daily |
18 |
1.11 (1.02, 1.22) |
1.47 (1.25, 1.73) |
-- |
CYP3A Substrate |
Midazolam |
Midazolam 2 mg singledose |
GZR |
200 mg once daily |
11 |
1.34 (1.29, 1.39) |
1.15 (1.01, 1.31) |
-- |
CYP2C8 Substrate |
Montelukast |
Montelukast 10 mg singledose |
GZR |
200 mg once daily |
23 |
1.11 (1.01, 1.20) |
0.92 (0.81, 1.06) |
1.39 (1.25, 1.56) |
HCV Antiviral |
GS-331007 |
Sofosbuvir 400 mg singledose |
EBR + GZR |
50 mg + 200 mg once daily |
16 |
1.13 (1.05, 1.21) |
0.87 (0.78, 0.96) |
1.53 (1.43, 1.63) |
Sofosbuvir |
Sofosbuvir 400 mg singledose |
EBR + GZR |
50 mg + 200 mg once daily |
16 |
2.43 (2.12, 2.79)‡ |
2.27 (1.72, 2.99) |
-- |
HIV Protease Inhibitor |
Atazanavir/ ritonavir |
Atazanavir 300 mg/ ritonavir 100 mg once daily |
EBR |
50 mg once daily |
8 |
1.07 (0.98, 1.17) |
1.02 (0.96, 1.08) |
1.15 (1.02, 1.29) |
Atazanavir 300 mg/ ritonavir 100 mg once daily |
GZR |
200 mg once daily |
11 |
1.43 (1.30, 1.57) |
1.12 (1.01, 1.24) |
1.23 (1.13, 1.34) |
Darunavir/ ritonavir |
Darunavir 600 mg/ ritonavir 100 mg twice daily |
EBR |
50 mg once daily |
8 |
0.95 (0.86, 1.06) |
0.95 (0.85, 1.05) |
0.94 (0.85, 1.05) |
Darunavir 600 mg/ ritonavir 100 mg twice daily |
GZR |
200 mg once daily |
13 |
1.11 (0.99, 1.24) |
1.10 (0.96, 1.25) |
1.00 (0.85, 1.18) |
Lopinavir/ ritonavir |
Lopinavir 400 mg/ ritonavir 100 mg twice daily |
EBR |
50 mg once daily |
9 |
1.02 (0.93, 1.13) |
1.02 (0.92, 1.13) |
1.07 (0.97, 1.18) |
Lopinavir 400 mg/ ritonavir 100 mg twice daily |
GZR |
200 mg once daily |
13 |
1.03 (0.96, 1.16) |
0.97 (0.88, 1.08) |
0.97 (0.81, 1.15) |
HIV Integrase Strand Transfer Inhibitor |
Dolutegravir |
Dolutegravir 50 mg singledose |
EBR + GZR |
50 mg + 200 mg once daily |
12 |
1.16 (1.00, 1.34) |
1.22 (1.05, 1.40) |
1.14 (0.95, 1.36) |
Raltegravir |
Raltegravir 400 mg singledose |
EBR |
50 mg single-dose |
10 |
1.02 (0.81, 1.27) |
1.09 (0.83, 1.44) |
0.99 (0.80, 1.22)§ |
Raltegravir 400 mg twice daily |
GZR |
200 mg once daily |
11 |
1.43 (0.89, 2.30) |
1.46 (0.78, 2.73) |
1.47 (1.09, 2.00) |
HIV Non-Nucleoside Reverse Transcriptase Inhibitor |
Efavirenz |
Efavirenz 600 mg once daily |
EBR |
50 mg once daily |
7 |
0.82 (0.78, 0.86) |
0.74 (0.67, 0.82) |
0.91 (0.87, 0.96) |
Efavirenz 600 mg once daily |
GZR |
200 mg once daily |
11 |
1.00 (0.96, 1.05) |
1.03 (0.99, 1.08) |
0.93 (0.88, 0.98) |
Rilpivirine |
Rilpivirine 25 mg once daily |
EBR + GZR |
50 mg + 200 mg once daily |
19 |
1.13 (1.07, 1.20) |
1.07 (0.97, 1.17) |
1.16 (1.09, 1.23) |
HIV Nucleotide Reverse Transcriptase Inhibitor |
Tenofovir disoproxil fumarate |
Tenofovir disoproxil fumarate 300 mg once daily |
EBR |
50 mg once daily |
10 |
1.34 (1.23, 1.47) |
1.47 (1.32, 1.63) |
1.29 (1.18, 1.41) |
Tenofovir disoproxil fumarate 300 mg once daily |
GZR |
200 mg once daily |
12 |
1.18 (1.09, 1.28) |
1.14 (1.04, 1.25) |
1.24 (1.10, 1.39) |
Tenofovir disoproxil fumarate 300 mg once daily |
EBR/GZR |
50 mg + 100 mg once daily |
13 |
1.27 (1.20, 1.35) |
1.14 (0.95, 1.36) |
1.23 (1.09, 1.40) |
HIV Fixed-Dose Combination Regimen |
Elvitegravir/ cobicistat/ emtricitabine/ tenofovir disoproxil fumarate |
Elvitegravir 150 mg once daily |
EBR/GZR |
50 mg / 100 mg once daily |
22 |
1.10 (1.00, 1.21) |
1.02 (0.93, 1.11) |
1.31 (1.11, 1.55) |
Cobicistat 150 mg once daily |
EBR/GZR |
50 mg / 100 mg once daily |
22 |
1.49 (1.42, 1.57) |
1.39 (1.29, 1.50) |
-- |
Emtricitabine 200 mg once daily |
EBR/GZR |
50 mg / 100 mg once daily |
22 |
1.07 (1.03, 1.10) |
0.96 (0.90, 1.02) |
1.19 (1.13, 1.25) |
|
Tenofovir disoproxil fumarate 300 mg once daily |
EBR/GZR |
50 mg / 100 mg once daily |
22 |
1.18 (1.13, 1.24) |
1.25 (1.14, 1.37) |
1.20 (1.15, 1.26) |
Immunosuppressant |
Cyclosporine |
Cyclosporine 400 mg singledose |
EBR + GZR |
50 mg + 200 mg once daily |
14 |
0.96 (0.90, 1.02) |
0.90 (0.85, 0.97) |
1.00 (0.92, 1.08)§ |
Mycophenolic acid |
Mycophenolate mofetil 1000 mg single-dose |
EBR + GZR |
50 mg + 200 mg once daily |
14 |
0.95 (0.87, 1.03) |
0.85 (0.67, 1.07) |
— |
Prednisolone |
Prednisone 40 mg singledose |
EBR + GZR |
50 mg + 200 mg once daily |
14 |
1.08 (1.01, 1.16) |
1.04 (0.99, 1.09) |
— |
Prednisone |
Prednisone 40 mg singledose |
EBR + GZR |
50 mg + 200 mg once daily |
14 |
1.08 (1.00, 1.17) |
1.05 (1.00, 1.10) |
-- |
Tacrolimus |
Tacrolimus 2 mg singledose |
EBR + GZR |
50 mg + 200 mg once daily |
16 |
1.43 (1.24, 1.64) |
0.60 (0.52, 0.69) |
1.70 (1.49, 1.94)§ |
Oral Contraceptive |
Ethinyl estradiol (EE) |
0.03 mg EE/ 0.15 mg LNG single-dose |
EBR |
50 mg once daily |
20 |
1.01 (0.97, 1.05) |
1.10 (1.05, 1.16) |
— |
GZR |
200 mg once daily |
20 |
1.10 (1.05, 1.14) |
1.05 (0.98, 1.12) |
— |
Levonorgestrel (LNG) |
EBR |
50 mg once daily |
20 |
1.14 (1.04, 1.24) |
1.02 (0.95, 1.08) |
-- |
GZR |
200 mg once daily |
20 |
1.23 (1.15, 1.32) |
0.93 (0.84, 1.03) |
-- |
Opioid Substitution Therapy |
Buprenorphine |
Buprenorphine 8 mg/Naloxone 2 mg singledose |
EBR |
50 mg once daily |
15 |
0.98 (0.89, 1.08) |
0.94 (0.82, 1.08) |
0.98 (0.88, 1.09) |
Buprenorphine 8-24 mg/ Naloxone 2-6 mg once daily |
GZR |
200 mg once daily |
12 |
0.98 (0.81, 1.19) |
0.90 (0.76, 1.07) |
-- |
R-Methadone |
Methadone 20-120 mg once daily |
EBR |
50 mg once daily |
10 |
1.03 (0.92, 1.15) |
1.07 (0.95, 1.20) |
1.10 (0.96, 1.26) |
Methadone 20-150 mg once daily |
GZR |
200 mg once daily |
12 |
1.09 (1.02, 1.17) |
1.03 (0.96, 1.11) |
-- |
S-Methadone |
Methadone 20-120 mg once daily |
EBR |
50 mg once daily |
10 |
1.09 (0.94, 1.26) |
1.09 (0.95, 1.25) |
1.20 (0.98, 1.47) |
|
Methadone 20-150 mg once daily |
GZR |
200 mg once daily |
12 |
1.23 (1.12, 1.35) |
1.15 (1.07, 1.25) |
-- |
Statin |
Atorvastatin |
Atorvastatin 10 mg singledose |
EBR + GZR |
50 mg + 200 mg once daily |
16 |
1.94 (1.63, 2.33) |
4.34 (3.10, 6.07) |
0.21 (0.17, 0.26) |
Pitavastatin |
Pitavastatin 1 mg singledose |
GZR |
200 mg once daily |
9 |
1.11 (0.91, 1.34) |
1.27 (1.07, 1.52) |
-- |
Pravastatin |
Pravastatin 40 mg singledose |
EBR + GZR |
50 mg + 200 mg once daily |
12 |
1.33 (1.09, 1.64)¶ |
1.28 (1.05, 1.55) |
-- |
Rosuvastatin |
Rosuvastatin 10 mg singledose |
EBR + GZR |
50 mg + 200 mg once daily |
12 |
2.26 (1.89, 2.69)# |
5.49 (4.29, 7.04) |
0.98 (0.84, 1.13) |
Abbreviations: EBR, elbasvir; GZR, grazoprevir; EBR +
GZR, administration of EBR and GZR as separate tablets; EBR/GZR, administration
of EBR and GZR as a single fixed-dose combination tablet
*AUC0-inf for single-dose administration; AUC0-24 for once daily
administration; AUC0-12 for twice daily administration
†C24 for once daily administration; C12 for twice daily administration.
‡N=14
§C12
¶N=10
#N=8 |
Microbiology
Mechanism Of Action
ZEPATIER combines two direct-acting antiviral agents with
distinct mechanisms of action and nonoverlapping resistance profiles to target
HCV at multiple steps in the viral lifecycle.
Elbasvir is an inhibitor of HCV NS5A, which is essential
for viral RNA replication and virion assembly. The mechanism of action of
elbasvir has been characterized based on cell culture antiviral activity and
drug resistance mapping studies.
Grazoprevir is an inhibitor of the HCV NS3/4A protease
which is necessary for the proteolytic cleavage of the HCV encoded polyprotein
(into mature forms of the NS3, NS4A, NS4B, NS5A, and NS5B proteins) and is
essential for viral replication. In a biochemical assay, grazoprevir inhibited
the proteolytic activity of the recombinant HCV genotype 1a, 1b, and 4a NS3/4A
protease enzymes with IC50 values of 7 pM, 4 pM, and 62 pM, respectively.
Antiviral Activity
In HCV replicon assays, the EC50 values of elbasvir
against full-length replicons from genotypes 1a, 1b, and 4, were 4 pM, 3 pM,
and 0.3 pM, respectively. The median EC50 values of elbasvir against chimeric replicons
encoding NS5A sequences from clinical isolates were 5 pM for genotype 1a (range
3-9 pM; N=5), 9 pM for genotype 1b (range 5-10 pM; N=4), 0.2 pM for genotype 4a
(range 0.2-0.2 pM; N=2), 3,600 pM for genotype 4b (range 17 pM-34,000 pM; N=3),
0.45 pM for genotype 4d (range 0.4-0.5 pM; N=2), 1.9 pM for genotype 4f (N=1),
36.3 pM for genotype 4g (range 0.6-72 pM; N=2), 0.6 pM for genotype 4m (range 0.4-0.7
pM; N=2), 2.2 pM for genotype 4o (N=1), and 0.5 pM for genotype 4q (N=1).
In HCV replicon assays, the EC50 values of grazoprevir
against full-length replicons from genotypes 1a, 1b, and 4, were 0.4 nM, 0.5
nM, and 0.3 nM, respectively. The median EC50 values of grazoprevir against
chimeric replicons encoding NS3/4A sequences from clinical isolates were 0.8 nM
for genotype 1a (range 0.4-5.1 nM; N=10), 0.3 nM for genotype 1b (range 0.2-5.9
nM; N=9), 0.3 nM for genotype 4a (N=1), 0.16 nM for genotype 4b (range 0.11-0.2
nM; N=2), and 0.24 nM for genotype 4g (range 0.15-0.33 nM; N=2).
Combination Antiviral Activity
Evaluation of elbasvir in combination with grazoprevir or
ribavirin showed no antagonistic effect in reducing HCV RNA levels in replicon
cells. Evaluation of grazoprevir in combination with ribavirin showed no
antagonistic effect in reducing HCV RNA levels in replicon cells.
Resistance
In Cell Culture
HCV replicons with reduced susceptibility to elbasvir and
grazoprevir have been selected in cell culture for genotypes 1a, 1b, and 4
which resulted in the emergence of resistance-associated amino acid substitutions
in NS5A or NS3, respectively. The majority of amino acid substitutions in NS5A
or NS3 selected in cell culture or identified in Phase 2b and 3 clinical trials
were phenotypically characterized in genotype 1a, 1b, or 4 replicons.
For elbasvir, in HCV genotype 1a replicons, single NS5A
substitutions M28A/G/T, Q30D/E/H/K/R, L31M/V, H58D, and Y93C/H/N reduced
elbasvir antiviral activity by 1.5- to 2,000-fold. In genotype 1b replicons,
single NS5A substitutions L28M, L31F, and Y93H reduced elbasvir antiviral activity
by 2- to 17- fold. In genotype 4 replicons, single NS5A substitutions L30S,
M31V, and Y93H reduced elbasvir antiviral activity by 3- to 23-fold. In
general, in HCV genotype 1a, 1b, or 4 replicons, combinations of elbasvir resistance-associated
substitutions further reduced elbasvir antiviral activity.
For grazoprevir, in HCV genotype 1a replicons, single NS3
substitutions Y56H, R155K, A156G/T/V, and D168A/E/G/N/S/V/Y reduced grazoprevir
antiviral activity by 2- to 81-fold; V36L/M, Q80K/R, or V107I single
substitutions had no impact on grazoprevir antiviral activity in cell culture.
In genotype 1b replicons, single NS3 substitutions F43S, Y56F, V107I,
A156S/T/V, and D168A/G/V reduced grazoprevir antiviral activity by 1.5- to
375-fold. In genotype 4 replicons, single NS3 substitutions D168A/V reduced
grazoprevir antiviral activity by 110- to 320-fold. In general, in HCV genotype
1a, 1b, or 4 replicons, combinations of grazoprevir resistance-associated
substitutions further reduced grazoprevir antiviral activity.
In Clinical Studies
In a pooled analysis of subjects treated with regimens
containing ZEPATIER or elbasvir + grazoprevir with or without ribavirin in
Phase 2 and 3 clinical trials, resistance analyses of both drug targets were conducted
for 50 subjects who experienced virologic failure and had sequence data
available (6 with ontreatment virologic failure, 44 with post-treatment
relapse). Treatment-emergent substitutions observed in the viral populations of
these subjects based on HCV genotypes and subtypes are shown in Table 10. Treatment-emergent
NS5A substitutions were detected in 30/37 (81%) genotype 1a-, 7/8 (88%)
genotype 1b-, and 5/5 (100%) genotype 4-infected subjects. The most common
treatment-emergent NS5A substitutions in genotype 1a were at position Q30
(n=22). Treatment-emergent NS3 substitutions were detected in 29/37 (78%)
genotype 1a-, 2/8 (25%) genotype 1b-, and 2/5 (40%) genotype 4-infected subjects.
The most common treatment-emergent NS3 substitutions in genotype 1a were at
position D168 (n=18). Treatment-emergent substitutions were detected in both
HCV drug targets in 23/37 (62%) genotype 1a-, 1/8 (13%) genotype 1b-, and 2/5
(40%) genotype 4-infected subjects.
Table 10: Treatment-Emergent Amino Acid Substitutions
Among Virologic Failures in the Pooled Analysis of ZEPATIER with and without
Ribavirin Regimens in Phase 2 and Phase 3 Clinical Trials
Target |
Genotype 1a
N = 37 |
Genotype 1b
N = 8 |
Genotype 4
N = 5 |
NS5A |
M28A/G/T, Q30H/K/R/Y, L31F/M/V, H58D, Y93H/N/S |
L28M, L31F/V, Y93H |
L28S/T, M31I/V, P58D, Y93H |
NS3 |
V36L/M, Y56H, V107I, R155I/K, A156G/T/V, V158A, D168A/G/N/V/Y |
Y56F, V107I, A156T |
A156M/T/V, D168A/G, V170I |
Persistence Of Resistance-Associated Substitutions
The persistence of elbasvir and grazoprevir
treatment-emergent amino acid substitutions in NS5A, and NS3, respectively, was
assessed in HCV genotype 1-infected subjects in Phase 2 and 3 trials whose virus
had treatment-emergent resistance-associated substitutions in the drug target,
and with available data through at least 24 weeks post-treatment using
population nucleotide sequence analysis.
Viral populations with treatment-emergent NS5A
resistance-associated substitutions were generally more persistent than those
with NS3 resistance-associated substitutions. Among genotype 1a-infected subjects,
NS5A resistance-associated substitutions persisted at detectable levels at
follow-up week 12 in 95% (35/37) of subjects and in 100% (9/9) of subjects with
follow-up week 24 data. Among genotype 1binfected subjects, NS5A
resistance-associated substitutions persisted at detectable levels in 100%
(7/7) of subjects at follow-up week 12 and in 100% (3/3) of subjects with
follow-up week 24 data.
Among genotype 1a-infected subjects, NS3
resistance-associated substitutions persisted at detectable levels at follow-up
week 24 in 31% (4/13) of subjects. Among genotype 1b-infected subjects, NS3
resistance-associated substitutions persisted at detectable levels at follow-up
week 24 in 50% (½) of subjects.
Due to the limited number of genotype 4-infected subjects
with treatment-emergent NS5A and NS3 resistance-associated substitutions,
trends in persistence of treatment-emergent substitutions in this genotype
could not be established.
The lack of detection of a virus containing a
resistance-associated substitution does not necessarily indicate that viral
populations carrying that substitution have declined to a background level that
may have existed prior to treatment. The long-term clinical impact of the
emergence or persistence of virus containing ZEPATIER-resistance-associated
substitutions is unknown.
Effect Of Baseline HCV Amino Acid Polymorphisms On Treatment
Response In Genotype 1-Infected Subjects
Analyses using population nucleotide sequencing were
conducted to explore the association between NS5A or NS3 amino acid
polymorphisms and treatment response among treatment-Naive and
treatmentexperienced genotype 1-infected subjects. Baseline NS5A polymorphisms
at resistance-associated positions (focusing on any change from subtype
reference at NS5A amino acid positions 28, 30, 31, or 93) were evaluated.
Baseline NS3 polymorphisms at positions 36, 54, 55, 56, 80, 107, 122, 132, 155,
156, 158, 168, 170, or 175 were evaluated. Analyses of SVR12 rates pooled data
from subjects Naive to direct-acting antivirals and who received ZEPATIER with
or without ribavirin in Phase 3 clinical trials, and censored subjects who did
not achieve SVR12 for reasons unrelated to virologic failure.
Genotype 1a
In genotype 1a-infected subjects, the presence of one or
more HCV NS5A amino acid polymorphisms at position M28, Q30, L31, or Y93 was
associated with reduced efficacy of ZEPATIER for 12 weeks (Table 11),
regardless of prior treatment history or cirrhosis status. The prevalence of
polymorphisms at any of these positions in genotype 1a-infected subjects was
11% (62/561) overall, and 12% (37/309) specifically for subjects in the U.S.
across Phase 2 and Phase 3 clinical trials evaluating ZEPATIER for 12 weeks or ZEPATIER
plus ribavirin for 16 weeks. The prevalence of polymorphisms at these positions
in genotype 1a-infected subjects was 6% (35/561) at position M28, 2% (11/561)
at position Q30, 3% (15/561) at position L31, and 2% (10/561) at position Y93.
Polymorphisms at NS5A position H58 were common (10%) and were not associated
with reduced ZEPATIER efficacy, except for a single virologic failure subject
whose virus had baseline M28V and H58D polymorphisms.
The SVR12 rates for subjects treated with ZEPATIER for 12
weeks were 88% (29/33) for subjects with M28V/T/L polymorphisms (n=29, 3, and
1, respectively), 40% (4/10) for subjects with Q30H/R/L polymorphisms (n=5, 3,
and 2, respectively), 38% (5/13) for subjects with an L31M polymorphism, and
63% (5/8) for subjects with Y93C/H/N/S polymorphisms (n=3, 3, 1, and 1,
respectively). Although data are limited, among genotype 1a-infected subjects
with these NS5A polymorphisms who received ZEPATIER plus ribavirin for 16
weeks, six out of six subjects achieved SVR12. The specific NS5A polymorphisms observed
in subjects treated with ZEPATIER plus ribavirin for 16 weeks included M28V
(n=2), Q30H (n=1), L31M (n=2), or Y93C/H (n=1 each).
Table 11: SVR12 in HCV Genotype 1a-Infected Subjects
without or with Baseline NS5A Polymorphisms
NS5A Polymorphism Status |
ZEPATIER 12 Weeks SVR12 % (n/N) |
ZEPATIER + RBV 16 Weeks SVR12 % (n/N) |
Without baseline NS5A polymorphism (M28, Q30, L31, or Y93) |
98% (441/450) |
100% (49/49) |
With baseline NS5A polymorphism (M28*, Q30*, L31*, or Y93*) |
70% (39/56) |
100% (6/6) |
*Any change from GT1a reference. |
There are insufficient data to determine the impact of
HCV NS5A amino acid polymorphisms in treatment-experienced subjects who failed
prior PegIFN + RBV + HCV protease inhibitor therapy and received ZEPATIER with
ribavirin.
In genotype 1a-infected subjects, the NS3 Q80K polymorphism
did not impact treatment response. Polymorphisms at other NS3
resistance-associated positions were uncommon and were not associated with
reduced treatment efficacy.
Genotype 1b
In genotype 1b-infected subjects treated with ZEPATIER
for 12 weeks, SVR12 rates (non-virologic failure-censored) were 94% (48/51) and
99% (247/248) for those with and without one or more NS5A polymorphisms at
position 28, 30, 31, or 93.
In genotype 1b-infected subjects, baseline NS3
polymorphisms did not impact treatment response.
Effect Of Baseline HCV Polymorphisms On Treatment
Response In Genotype 4-Infected Subjects
Phylogenetic analysis of HCV sequences from genotype
4-infected subjects (n=71) in the pooled analyses of subjects (non-virologic
failure-censored) treated with regimens containing ZEPATIER or elbasvir +
grazoprevir with or without ribavirin in Phase 2 and 3 clinical trials
identified 4 HCV genotype 4 subtypes (4a, 4d, 4k, 4o). Most subjects were
infected with either subtype 4a (42%) or 4d (51%); 1 to 2 subjects were
infected with each of the other genotype 4 subtypes. Among subjects enrolled at
U.S. study sites, 11/13 (85%) were infected with HCV subtype 4a. There were two
subjects infected with HCV subtype 4d who experienced virologic failure with
the regimen containing grazoprevir and elbasvir.
In genotype 4-infected subjects, SVR12 rates for subjects
with baseline NS5A polymorphisms (any change from reference at NS5A amino acid
positions 28, 30, 31, 58, and 93 by population nucleotide sequencing) were 100%
(28/28) and for subjects without baseline NS5A polymorphisms were 95% (41/43).
In genotype 4-infected subjects, SVR12 rates for subjects
with baseline NS3 polymorphisms (any change from reference at NS3 amino acid
positions 36, 54, 55, 56, 80, 107, 122, 132, 155, 156, 158, 168, 170, and 175
by population nucleotide sequencing) were 100% (18/18) and for subjects without
baseline NS3 polymorphisms were 96% (51/53).
Cross Resistance
Cross resistance is possible among NS5A inhibitors and
NS3/4A protease inhibitors by class. Elbasvir and grazoprevir are fully active
against viral populations with substitutions conferring resistance to NS5B
inhibitors.
In the C-SALVAGE trial, subjects with genotype 1
infection who had failed prior treatment with boceprevir (n=28), simeprevir
(n=8), or telaprevir (n=43) in combination with PegIFN + RBV received EBR 50 mg
once daily + GZR 100 mg once daily + RBV for 12 weeks. There are limited data
to determine the impact of HCV NS3 resistance-associated substitutions detected
at baseline in treatment-experienced subjects who failed prior PegIFN + RBV +
HCV protease inhibitor therapy and received ZEPATIER with ribavirin. SVR was
achieved in 88% (21/24) of genotype 1a and genotype 1b infected subjects with
NS3 resistance-associated substitutions detected at baseline. Specific NS3
substitutions observed at baseline included one or more of the following:
V36L/M (n=8), T54S (n=4), S122G/T (n=9), R155K/T (n=9), A156S/T (n=1), and
D168E/N (n=3). SVR was 100% (55/55) in subjects without baseline NS3 resistance
substitutions. The 3 virologic failure subjects had the following NS3 or NS5A
substitutions/polymorphisms at baseline: NS3 R155T/D168N, NS3 R155K plus NS5A
H58D, and NS3 T54S plus NS5A L31M.
The efficacy of ZEPATIER has not been established in
patients who have previously failed treatment with other regimens that included
an NS5A inhibitor.
Clinical Studies
Overview Of Clinical Trials
The efficacy of ZEPATIER was assessed in 2
placebo-controlled trials and 4 uncontrolled Phase 2 and 3 clinical trials in
1401 subjects with genotype (GT) 1, 4, or 6 chronic hepatitis C virus infection
with compensated liver disease (with or without cirrhosis). An overview of the
6 trials (n=1373) contributing to the assessment of efficacy in genotype 1 or 4
is provided in Table 12. C-EDGE TN, C-EDGE COINFECTION, C-SCAPE, and C-EDGE TE
also included subjects with genotype 6 HCV infection (n=28). Because ZEPATIER
is not indicated for genotype 6 infection, results in patients with genotype 6
infection are not included in Clinical Studies.
Table 12: Trials Conducted with ZEPATIER
Trial |
Population |
Study Groups and Duration (Number of Subjects Treated) |
C-EDGE TN (double-blind) |
GT 1, 4 TN with or without cirrhosis |
- ZEPATIER for 12 weeks (N=306)
- Placebo for 12 weeks (N=102)
|
C-EDGE COINFECTION (open-label) |
GT 1, 4 TN with or without cirrhosis HCV/HIV-1 co-infection |
- ZEPATIER for 12 weeks (N=217)
|
C-SURFER (double-blind) |
GT 1 TN or TE with or without cirrhosis Severe Renal Impairment including Hemodialysis |
- EBR* + GZR* for 12 weeks (N= 122)
- Placebo for 12 weeks (N= 113)
|
C-SCAPE (open-label) |
GT 4 TN without cirrhosis |
EBR* + GZR* for 12 weeks (N= 10)
EBR* + GZR* + RBV for 12 weeks (N= 10) |
C-EDGE TE (open-label) |
GT 1, 4 TE with or without cirrhosis with or without HCV/HIV-1 co-infection |
- ZEPATI ER for 12 or 16 weeks (N=105 and 101, respectively)
- ZEPATI ER + RBV for 12 or 16 weeks (N=104 and 104, respectively)
|
C-SALVAGE (open-label) |
GT 1 TE with HCV protease inhibitor regimen† with or without cirrhosis |
- EBR* + GZR* + RBV for 12 weeks (N=79)
|
GT = Genotype
TN = Treatment-Naive
TE = Treatment-Experienced (failed prior treatment with interferon [IFN] or
peginterferon alfa [PegIFN] with or without ribavirin [RBV] or were intolerant
to prior therapy).
*EBR = elbasvir 50 mg; GZR = grazoprevir 100 mg; EBR + GZR = co-administered as
single agents.
† Failed prior treatment with boceprevir, telaprevir, or simeprevir in
combination with PegIFN + RBV. |
ZEPATIER was administered once daily by mouth in these
trials. For subjects who received ribavirin (RBV), the RBV dosage was
weight-based (less than 66 kg = 800 mg per day, 66 to 80 kg = 1000 mg per day,
81 to 105 kg = 1200 mg per day, greater than 105 kg = 1400 mg per day)
administered by mouth in two divided doses with food.
Sustained virologic response (SVR) was the primary
endpoint in all trials and was defined as HCV RNA less than lower limit of
quantification (LLOQ) at 12 weeks after the cessation of treatment (SVR12). Serum
HCV RNA values were measured during these clinical trials using the COBAS
AmpliPrep/COBAS Taqman HCV test (version 2.0) with an LLOQ of 15 HCV RNA IU per
mL, with the exception of C-SCAPE where the assay had an LLOQ of 25 HCV RNA IU
per mL.
Clinical Trials In Treatment-Naive Subjects With Genotype
1 HCV (C-EDGE TN And C-EDGE COINFECTION)
The efficacy of ZEPATIER in treatment-Naive subjects with
genotype 1 chronic hepatitis C virus infection with or without cirrhosis was
demonstrated in the C-EDGE TN and C-EDGE COINFECTION trials.
C-EDGE TN was a randomized, double-blind,
placebo-controlled trial in treatment-Naive subjects with genotype 1 or 4
infection with or without cirrhosis. Subjects were randomized in a 3:1 ratio
to: ZEPATIER for 12 weeks (immediate treatment group) or placebo for 12 weeks
followed by open-label treatment with ZEPATIER for 12 weeks (deferred treatment
group). Among subjects with genotype 1 infection randomized to the immediate
treatment group, the median age was 55 years (range: 20 to 78); 56% of the
subjects were male; 61% were White; 20% were Black or African American; 8% were
Hispanic or Latino; mean body mass index was 26 kg/m²; 72% had baseline HCV RNA
levels greater than 800,000 IU per mL; 24% had cirrhosis; 67% had non-C/C IL28B
alleles (CT or TT); and 55% had genotype 1a and 45% had genotype 1b chronic HCV
infection.
C-EDGE COINFECTION was an open-label, single-arm trial in
treatment-Naive HCV/HIV-1 coinfected subjects with genotype 1 or 4 infection
with or without cirrhosis. Subjects received ZEPATIER for 12 weeks. Among
subjects with genotype 1 infection, the median age was 50 years (range: 21 to
71); 85% of the subjects were male; 75% were White; 19% were Black or African
American; 6% were Hispanic or Latino; mean body mass index was 25 kg per m²;
59% had baseline HCV RNA levels greater than 800,000 IU per mL; 16% had
cirrhosis; 65% had non-C/C IL28B alleles (CT or TT); and 76% had genotype 1a,
23% had genotype 1b, and 1% had genotype 1-Other chronic HCV infection.
Table 13 presents treatment outcomes for ZEPATIER in
treatment-Naive subjects with genotype 1 infection from C-EDGE TN (immediate
treatment group) and C-EDGE COINFECTION. For treatment outcomes for ZEPATIER in
genotype 4 infection, [see Clinical Studies].
Table 13: C-EDGE TN and C-EDGE COINFECTION: SVR12 in
Treatment-Naive Subjects with or without Cirrhosis with Genotype 1 HCV Treated
with ZEPATIER for 12 Weeks
Trial |
C-EDGE TN (Immediate Treatment Group) |
C-EDGE COINFECTION (HCV/HIV-1 Co-Infection) |
Regimen |
ZEPATIER 12 Weeks
N=288 |
ZEPATIER 12 Weeks
N=189 |
SVR in Genotype 1 |
95% (273/288) |
95% (179/189) |
Outcome for subjects without SVR |
On-treatment Virologic Failure* |
<1% (1/288) |
0% (0/189) |
Relapse |
3% (10/288) |
3% (6/189) |
Other† |
1% (4/288) |
2% (4/189) |
SVR by Genotype 1 Subtypes |
GT 1a‡ |
92% (144/157) |
94% (136/144) |
GT 1b§ |
98% (129/131) |
96% (43/45) |
SVR by Cirrhosis status |
Non-cirrhotic |
94% (207/220) |
94% (148/158) |
Cirrhotic |
97% (66/68) |
100% (31/31) |
*Includes subjects with virologic breakthrough.
†Other includes subjects who discontinued due to adverse event, lost to
follow-up, or subject withdrawal.
‡For the impact of baseline NS5A polymorphisms on SVR12, [see Microbiology],
Table 11.
§Includes genotype 1 subtypes other than 1a or 1b. |
Clinical Trials In Treatment-Experienced Subjects With Genotype
1 HCV
Treatment-Experienced Subjects Who Failed Prior PegIFN With
RBV Therapy (C-EDGE TE)
C-EDGE TE was a randomized, open-label comparative trial
in subjects with genotype 1 or 4 infection, with or without cirrhosis, with or
without HCV/HIV-1 co-infection, who had failed prior therapy with PegIFN + RBV
therapy. Subjects were randomized in a 1:1:1:1 ratio to one of the following
treatment groups: ZEPATIER for 12 weeks, ZEPATIER + RBV for 12 weeks, ZEPATIER
for 16 weeks, or ZEPATIER + RBV for 16 weeks. Among subjects with genotype 1
infection, the median age was 57 years (range: 19 to 77); 64% of the subjects
were male; 67% were White; 18% were Black or African American; 9% were Hispanic
or Latino; mean body mass index was 28 kg/m²; 78% had baseline HCV RNA levels
greater than 800,000 IU/mL; 34% had cirrhosis; 79% had non-C/C IL28B alleles
(CT or TT); and 60% had genotype 1a, 39% had genotype 1b, and 1% had genotype
1-Other chronic HCV infection.
Treatment outcomes in genotype 1 subjects treated with
ZEPATIER for 12 weeks or ZEPATIER with RBV for 16 weeks are presented in Table
14. Treatment outcomes with ZEPATIER with RBV for 12 weeks or without RBV for
16 weeks are not shown because these regimens are not recommended in
PegIFN/RBVexperienced genotype 1 patients. For treatment outcomes for ZEPATIER
in genotype 4 infection, [see Clinical Studies].
Table 14: C-EDGE TE: SVR12 in Treatment-Experienced
Subjects who Failed Prior PegIFN with RBV with or without Cirrhosis, with or
without HCV/HIV-1 Co-infection with Genotype 1 HCV Treated with ZEPATIER for 12
Weeks or ZEPATIER with Ribavirin for 16 Weeks
Regimen |
ZEPATIER 12 weeks
N=96 |
ZEPATIER + RBV 16 weeks
N=96 |
SVR in Genotype 1 |
94% (90/96) |
97% (93/96) |
Outcome for subjects without SVR |
On-treatment Virologic Failure* |
0% (0/96) |
0% (0/96) |
Relapse |
5% (5/96) |
0% (0/96) |
Other† |
1% (1/96) |
3% (3/96) |
SVR by Genotype 1 Subtypes |
GT 1a‡ |
90% (55/61) |
95% (55/58) |
GT 1b§ |
100% (35/35) |
100% (38/38) |
SVR by Cirrhosis status |
Non-cirrhotic |
94% (61/65) |
95% (61/64) |
Cirrhotic |
94% (29/31) |
100% (32/32) |
SVR by Response to Prior HCV Therapy |
On-treatment Virologic Failure¶ |
90% (57/63) |
95% (58/61) |
Relapser |
100% (33/33) |
100% (35/35) |
*Includes subjects with virologic breakthrough or
rebound.
†Other includes subjects who discontinued due to adverse event, lost to
follow-up, or subject withdrawal.
‡For the impact of baseline NS5A polymorphisms on SVR, [see Microbiology],
Table 11.
§Includes genotype 1 subtypes other than 1a or 1b.
¶Includes prior null responders and partial responders. |
Treatment-Experienced Subjects Who Failed Prior PegIFN +
RBV + HCV Protease Inhibitor Therapy (CSALVAGE)
C-SALVAGE was an open-label single-arm trial in subjects
with genotype 1 infection, with or without cirrhosis, who had failed prior
treatment with boceprevir, simeprevir, or telaprevir in combination with PegIFN
+ RBV. Subjects received EBR 50 mg once daily + GZR 100 mg once daily + RBV for
12 weeks. Subjects had a median age of 55 years (range: 23 to 75); 58% of the
subjects were male; 97% were White; 3% were Black or African American; 15% were
Hispanic or Latino; mean body mass index was 28 kg/m²; 63% had baseline HCV RNA
levels greater than 800,000 IU/mL; 43% had cirrhosis; and 97% had non-C/C IL28B
alleles (CT or TT); 46% had baseline NS3 resistance-associated substitutions.
Overall SVR was achieved in 96% (76/79) of subjects
receiving EBR + GZR + RBV for 12 weeks. Four percent (3/79) of subjects did not
achieve SVR due to relapse. Treatment outcomes were consistent in genotype 1a
and genotype 1b subjects, in subjects with different response to previous HCV
therapy, and in subjects with or without cirrhosis. Treatment outcomes were
generally consistent in subjects with or without NS3 resistance-associated
substitutions at baseline, although limited data are available for subjects with
specific NS3 resistance-associated substitutions [see Microbiology].
Clinical Trial In Subjects With Genotype 1 HCV And Severe
Renal Impairment including Subjects On Hemodialysis (C-SURFER)
C-SURFER was a randomized, double-blind,
placebo-controlled trial in subjects with genotype 1 infection, with or without
cirrhosis, with chronic kidney disease (CKD) Stage 4 (eGFR 15-29 mL/min/1.73
m²) or CKD Stage 5 (eGFR <15 mL/min/1.73 m²), including subjects on
hemodialysis, who were treatment-Naive or who had failed prior therapy with IFN
or PegIFN ± RBV therapy. Subjects were randomized in a 1:1 ratio to one of the
following treatment groups: EBR 50 mg once daily + GZR 100 mg once daily for 12
weeks (immediate treatment group) or placebo for 12 weeks followed by
open-label treatment with EBR + GZR for 12 weeks (deferred treatment group). In
addition, 11 subjects received openlabel EBR + GZR for 12 weeks (intensive
pharmacokinetic [PK] group). Subjects randomized to the immediate treatment
group and intensive PK group had a median age of 58 years (range: 31 to 76);
75% of the subjects were male; 50% were White; 45% were Black or African
American; 11% were Hispanic or Latino; 57% had baseline HCV RNA levels greater
than 800,000 IU/mL; 6% had cirrhosis; and 72% had non-C/C IL28B alleles (CT or
TT).
Treatment outcomes in subjects treated with ZEPATIER for
12 weeks in the pooled immediate treatment group and intensive PK group are
presented in Table 15.
Table 15: C-SURFER: SVR12 in Subjects with Severe
Renal Impairment including Subjects on Hemodialysis who were Treatment-Naive or
had Failed Prior IFN or PegIFN ± RBV, with or without Cirrhosis, with Genotype
1 HCV Treated with ZEPATIER for 12 Weeks
Regimen |
EBR + GZR 12 weeks (Immediate Treatment Group)
N=122* |
Overall SVR |
94% (115/122)† |
Outcome for subjects without SVR |
On-treatment Virologic Failure |
0% (0/122) |
Relapse |
<1% (1/122) |
Other‡ |
5% (6/122) |
SVR by Genotype |
GT 1a |
97% (61/63) |
GT 1b§ |
92% (54/59) |
SVR by Cirrhosis status |
No |
95% (109/115) |
Yes |
86% (6/7) |
SVR by Prior HCV Treatment Status |
Treatment-naive |
95% (96/101) |
Treatment-experienced |
90% (19/21) |
SVR by Dialysis Status |
No |
97% (29/30) |
Yes |
93% (86/92) |
SVR by Chronic Kidney Disease Stage |
Stage 4 |
100% (22/22) |
Stage 5 |
93% (93/100) |
*Includes subjects (n=11) in the intensive PK group.
†SVR was achieved in 99% (115/116) of subjects in the pre-specified primary
analysis population, which excluded subjects not receiving at least one dose of
study treatment and those with missing data due to death or early study discontinuation
for reasons unrelated to treatment response.
‡Other includes subjects who discontinued due to adverse event, lost to
follow-up, or subject withdrawal.
§Includes genotype 1 subtypes other than 1a or 1b. |
Clinical Trials With Genotype 4 HCV
The efficacy of ZEPATIER in subjects with genotype 4
chronic HCV infection was demonstrated in C-EDGE TN, C-EDGE COINFECTION, C-EDGE
TE, and C-SCAPE. C-SCAPE was a randomized, openlabel trial which included
treatment-Naive subjects with genotype 4 infection without cirrhosis. Subjects
were randomized in a 1:1 ratio to EBR 50 mg once daily + GZR 100 mg once daily
for 12 weeks or EBR 50 mg once daily + GZR 100 mg once daily + RBV for 12
weeks. In these combined studies in subjects with genotype 4 infection, 64%
were treatment-Naive; 66% of the subjects were male; 87% were White; 10% were
Black or African American; 22% had cirrhosis; and 30% had HCV/HIV-1
co-infection.
In C-SCAPE, C-EDGE TN, and C-EDGE COINFECTION trials
combined, a total of 66 genotype 4 treatment-Naive subjects received ZEPATIER
or EBR + GZR for 12 weeks. In these combined trials, SVR12 among subjects
treated with ZEPATIER or EBR + GZR for 12 weeks was 97% (64/66).
In C-EDGE TE, a total of 37 genotype 4
treatment-experienced subjects received a 12- or 16-week ZEPATIER with or
without RBV regimen. SVR12 among randomized subjects treated with ZEPATIER + RBV
for 16 weeks was 100% (8/8).