CLINICAL PHARMACOLOGY
Mechanism Of Action
EPCLUSA is a fixed-dose
combination of sofosbuvir and velpatasvir which are direct-acting antiviral
agents against the hepatitis C virus [see Microbiology].
Pharmacodynamics
Cardiac Electrophysiology
The effect of sofosbuvir 400 mg
(recommended dosage) and 1200 mg (3 times the recommended dosage) on QTc
interval was evaluated in an active-controlled (moxifloxacin 400 mg) thorough
QT trial. At a dose 3 times the recommended dose, sofosbuvir does not prolong
QTc to any clinically relevant extent.
The effect of velpatasvir 500
mg (5 times the recommended dosage) was evaluated in an active-controlled
(moxifloxacin 400 mg) thorough QT trial. At a dose 5 times the recommended
dose, velpatasvir does not prolong QTc interval to any clinically relevant
extent.
Pharmacokinetics
The pharmacokinetic properties
of the components of EPCLUSA are provided in Table 3. The multiple dose
pharmacokinetic parameters of sofosbuvir and its metabolite, GS-331007, and
velpatasvir are provided in Table 4.
Table 3 : Pharmacokinetic Properties of the Components
of EPCLUSA
|
Sofosbuvir |
Velpatasvir |
Absorption |
Tmax (h) |
0.5-1 |
3 |
Effect of moderate meal (relative to fasting)a |
↑ 60% |
↑ 34% |
Effect of high fat meal (relative to fasting)a |
↑ 78% |
↑ 21% |
Distribution |
% Bound to human plasma proteins |
61-65 |
>99.5 |
Blood-to-plasma ratio |
0.7 |
0.52-0.67 |
Metabolism |
Metabolism |
Cathepsin A |
CYP2B6 |
|
CES1 |
CYP2C8 |
|
HINT1 |
CYP3A4 |
Elimination |
Major route of elimination |
SOF: metabolism |
|
|
GS-331007b: glomerular filtration and active tubular secretion |
Biliary excretion as parent (77%) |
t½ (h)c |
SOF: 0.5 GS-331007b: 25 |
15 |
% Of dose excreted in urined |
80e |
0.4 |
% Of dose excreted in fecesd |
14 |
94 |
CES1 = carboxylesterase 1;
HINT1 = histidine triad nucleotide-binding protein 1.
a Values refer to mean systemic exposure. Moderate meal =
~600 kcal, 30% fat; high fat meal = ~800 kcal, 50% fat. EPCLUSA can be taken
with or without food.
b GS-331007 is the primary circulating nucleoside metabolite of SOF.
c t½ values refer to median terminal plasma half-life.
d Single dose administration of [14C] SOF or [14C]
VEL in mass balance studies.
e Predominantly as GS-331007. |
Table 4 : Multiple Dose Pharmacokinetic Parameters of Sofosbuvir and its Metabolite, GS-331007, and
Velpatasvir Following Oral Administration of EPCLUSA in HCV-Infected Adults
Parameter Mean (%CV) |
Sofosbuvira |
GS-331007b |
Velpatasvirc |
Cmax (nanogram per mL) |
567 (30.7) |
898 (26.7) |
259 (54.3) |
AUCtau (nanogram•hr per mL) |
1268 (38.5) |
14372 (28.0) |
2980 (51.3) |
Ctrough (nanogram per mL) |
NA |
NA |
42 (67.3) |
CV = coefficient of variation; NA = not applicable.
a From Population PK analysis, N = 666
b From Population PK analysis, N = 1029
c From Population PK analysis, N = 1025 |
Sofosbuvir and GS-331007 AUC0-24
and Cmax were similar in healthy adult subjects and subjects with HCV
infection. Relative to healthy subjects (N=331), velpatasvir AUC0-24 and Cmax were
37% lower and 42% lower, respectively, in HCV-infected subjects.
Velpatasvir AUC increases in a
greater than proportional manner from 5 to 50 mg and in a less than
proportional manner from 50 to 450 mg in healthy volunteers. However,
velpatasvir exhibited more than or near dose-proportional increase in exposures
25 mg to 150 mg in HCV-infected patients when coadministered with sofosbuvir.
Sofosbuvir and GS-331007 AUCs are near dose-proportional over the dose
range of 200 mg to 1200 mg.
Specific Populations
Pediatric Patients
The pharmacokinetics of sofosbuvir or velpatasvir in
pediatric patients has not been established [see Use In Specific Populations].
Geriatric Patients
Population pharmacokinetic analysis in HCV-infected
subjects showed that within the age range (18 to 82 years) analyzed, age did
not have a clinically relevant effect on the exposure to sofosbuvir, GS-331007,
or velpatasvir [see Use In Specific Populations].
Patients With 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 subjects with 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 ADMINISTRATION and Use In Specific Populations].
The pharmacokinetics of velpatasvir were studied with a
single dose of 100 mg velpatasvir in HCV negative subjects with severe renal
impairment (eGFR less than 30 mL/min by Cockcroft-Gault). No clinically
relevant differences in velpatasvir pharmacokinetics were observed between
healthy subjects and subjects with severe renal impairment.
Patients With Hepatic Impairment
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, respectively). 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].
The pharmacokinetics of velpatasvir were studied with a
single dose of 100 mg velpatasvir in HCV negative subjects with moderate and
severe hepatic impairment (Child-Pugh Class B and C). Velpatasvir plasma
exposure (AUCinf) was similar in subjects with moderate hepatic impairment,
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 velpatasvir [see Use In Specific Populations].
Race
Population pharmacokinetics analysis in HCV-infected
subjects indicated that race had no clinically relevant effect on the exposure
of sofosbuvir, GS-331007, or velpatasvir.
Gender
Population pharmacokinetics analysis in HCV-infected
subjects indicated that gender had no clinically relevant effect on the
exposure of sofosbuvir, GS-331007, or velpatasvir.
Drug Interaction Studies
After oral administration of EPCLUSA, sofosbuvir is
rapidly absorbed and subject to extensive first-pass hepatic extraction (hydrolysis
followed by sequential phosphorylation) to form the pharmacologically active
triphosphate. In clinical pharmacology studies, both sofosbuvir and the primary
circulating metabolite GS-331007 (dephosphorylated nucleotide metabolite) were
monitored for purposes of pharmacokinetic analyses.
Sofosbuvir and velpatasvir are substrates of drug
transporters P-gp and BCRP while GS-331007 is not. Velpatasvir is also
transported by OATP1B1 and OATP1B3. In vitro, slow metabolic turnover of
velpatasvir by CYP2B6, CYP2C8, and CYP3A4 was observed. Inducers of P-gp and/or
moderate to potent inducers of CYP2B6, CYP2C8, or CYP3A4 (e.g., rifampin, St.
John's wort, carbamazepine) may decrease plasma concentrations of sofosbuvir
and/or velpatasvir, leading to reduced therapeutic effect of EPCLUSA [see WARNINGS AND PRECAUTIONS and DRUG
INTERACTIONS]. Coadministration with drugs that inhibit P-gp and/or BCRP
may increase sofosbuvir and/or velpatasvir plasma concentrations without
increasing GS-331007 plasma concentration. Drugs that inhibit CYP2B6, CYP2C8,
or CYP3A4 may increase plasma concentration of velpatasvir.
Velpatasvir is an inhibitor of drug transporter P-gp,
BCRP, OATP1B1, OATP1B3, and OATP2B1, and its involvement in drug interactions
with these transporters is primarily limited to the process of absorption. At
clinically relevant concentration, velpatasvir is not an inhibitor of hepatic
transporters OATP1A2 or OCT1, renal transporters OCT2, OAT1, OAT3 or MATE1, or
CYP or UGT1A1 enzymes.
Sofosbuvir and GS-331007 are not inhibitors of drug
transporters P-gp, BCRP, OATP1B1, OATP1B3, and OCT1 and GS-331007 is not an
inhibitor of OAT1, OAT3, OCT2, and MATE1. Sofosbuvir and GS-331007 are not
inhibitors or inducers of CYP or UGT1A1 enzymes.
The effects of coadministered drugs on the exposure of
sofosbuvir, GS-331007, and velpatasvir are shown in Table 5. The effects of
sofosbuvir, velpatasvir, or EPCLUSA on the exposure of coadministered drugs are
shown in Table 6.
Table 5 : Drug Interactions: Changes in
Pharmacokinetic Parameters for Sofosbuvir, GS-331007, and Velpatasvir in the
Presence of the Coadministered Druga
Coadministered Drug |
Dose of Coadministered Drug (mg) |
SOF Dose (mg) |
VEL Dose (mg) |
N |
Mean Ratio (90% CI) of Sofosbuvir, GS-331007, and Velpatasvir PK With/Without Coadministered Drug No Effect=1.00 |
|
Cmax |
AUC |
Cmin |
Atazanavir/ ritonavir + emtricitabine/ tenofovir DF |
300/100 + 200/300 once daily |
400 once daily |
100 once daily |
24 |
sofosbuvir |
1.12 (0.97, 1.29) |
1.22 (1.12, 1.33) |
NA |
GS-331007 |
1.21 (1.12, 1.29) |
1.32 (1.27, 1.36) |
1.42 (1.37, 1.49) |
velpatasvir |
1.55 (1.41, 1.71) |
2.42 (2.23, 2.64) |
4.01 (3.57, 4.50) |
Cyclosporine |
600 single dose |
400 single dose |
ND |
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 |
ND |
100 single dose |
12 |
velpatasvir |
1.56 (1.22, 2.01) |
2.03 (1.51, 2.71) |
NA |
Darunavir/ ritonavir + emtricitabine/ tenofovir DF |
800/100 + 200/300 once daily |
400 once daily |
100 once daily |
29 |
sofosbuvir |
0.62 (0.54, 0.71) |
0.72 (0.66, 0.80) |
NA |
GS-331007 |
1.04 (0.99, 1.08) |
1.13 (1.08, 1.18) |
1.13 (1.06, 1.19) |
velpatasvir |
0.76 (0.65, 0.89) |
0.84 (0.72, 0.98) |
1.01 (0.87, 1.18) |
Efavirenz/ emtricitabine/ tenofovir DFb |
600/200/300 once daily |
400 once daily |
100 once daily |
14 |
sofosbuvir |
1.38 (1.14, 1.67) |
0.97 (0.83, 1.14) |
NA |
GS-331007 |
0.86 (0.80, 0.93) |
0.90 (0.85, 0.96) |
1.01 (0.95, 1.07) |
velpatasvir |
0.53 (0.43, 0.64) |
0.47 (0.39, 0.57) |
0.43 (0.36, 0.52) |
Elvitegravir/ cobicistat/ emtricitabine/ tenofovir alafenamidec |
150/150/200/10 once daily |
400 once daily |
100 once daily |
24 |
sofosbuvir |
1.23 (1.07, 1.42) |
1.37 (1.24, 1.52) |
NA |
GS-331007 |
1.29 (1.25, 1.33) |
1.48 (1.43, 1.53) |
1.58 (1.52, 1.65) |
velpatasvir |
1.30 (1.17, 1.45) |
1.50 (1.35, 1.66) |
1.60 (1.44, 1.78) |
Elvitegravir/ cobicistat/ emtricitabine/ tenofovir DFd |
150/150/200/30 0 once daily |
400 once daily |
100 once daily |
24 |
sofosbuvir |
1.01 (0.85, 1.19) |
1.24 (1.13, 1.37) |
NA |
GS-331007 |
1.13 (1.07, 1.18) |
1.35 (1.30, 1.40) |
1.45 (1.38, 1.52) |
velpatasvir |
1.05 (0.93, 1.19) |
1.19 (1.07, 1.34) |
1.37 (1.22, 1.54) |
Famotiain! |
40 single dose simultaneously with EPCLUSA |
400 single dose |
100 single dose |
60 |
sofosbuvir |
0.92 (0.82, 1.05) |
0.82 (0.74, 0.91) |
NA |
GS-331007 |
0.84 (0.78, 0.89) |
0.94 (0.91, 0.98) |
NA |
velpatasvir |
0.80 (0.70, 0.91) |
0.81 (0.71, 0.91) |
NA |
40 single dose 12 hours prior to EPCLUSA |
60 |
sofosbuvir |
0.77 (0.68, 0.87) |
0.80 (0.73, 0.88) |
NA |
GS-331007 |
1.20 (1.13, 1.28) |
1.04 (1.01, 1.08) |
NA |
velpatasvir |
0.87 (0.76, 1.00) |
0.85 (0.74, 0.97) |
NA |
Ketoconazole |
200 twice daily |
ND |
100 single dose |
12 |
velpatasvir |
1.29 (1.02, 1.64) |
1.71 (1.35, 2.18) |
NA |
Lopinavir/ ritonavir + emtricitabine/ tenofovir DF |
4x200/50 + 200/300 once daily |
400 once daily |
100 once daily |
24 |
sofosbuvir |
0.59 (0.49, 0.71) |
0.71 (0.64, 0.78) |
NA |
GS-331007 |
1.01 (0.98, 1.05) |
1.15 (1.09, 1.21) |
1.15 (1.07, 1.25) |
velpatasvir |
0.70 (0.59, 0.83) |
1.02 (0.89, 1.17) |
1.63 (1.43, 1.85) |
Methadone |
30 to 130 daily |
400 once daily |
ND |
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 simultaneously with EPCLUSA |
400 single dose fasted |
100 single dose fasted |
60 |
sofosbuvir |
0.66 (0.55, 0.78) |
0.71 (0.60, 0.83) |
NA |
GS-331007 |
1.18 (1.10, 1.26) |
1.00 (0.95, 1.05) |
NA |
velpatasvir |
0.63 (0.50, 0.78) |
0.64 (0.52, 0.79) |
NA |
20 once daily 12 hours prior to EPCLUSA |
400 single dose fasted |
100 single dose fasted |
60 |
sofosbuvir |
0.55 (0.47, 0.64) |
0.56 (0.49, 0.65) |
NA |
GS-331007 |
1.26 (1.18, 1.34) |
0.97 (0.94, 1.01) |
NA |
velpatasvir |
0.43 (0.35, 0.54) |
0.45 (0.37, 0.55) |
NA |
20 once daily 2 hours prior to EPCLUSA |
400 single dose fede |
100 single dose fede |
40 |
sofosbuvir |
0.84 (0.68, 1.03) |
1.08 (0.94, 1.25) |
NA |
GS-331007 |
0.94 (0.88, 1.02) |
0.99 (0.96, 1.03) |
NA |
velpatasvir |
0.52 (0.43, 0.64) |
0.62 (0.51, 0.75) |
NA |
20 once daily 4 hours after EPCLUSA |
400 single dose fede |
100 single dose fede |
38 |
sofosbuvir |
0.79 (0.68, 0.92) |
1.05 (0.94, 1.16) |
NA |
GS-331007 |
0.91 (0.85, 0.98) |
0.99 (0.95, 1.02) |
NA |
velpatasvir |
0.67 (0.58, 0.78) |
0.74 (0.63, 0.86) |
NA |
40 once daily 4 hours after EPCLUSA |
400 single dose fede |
100 single dose fede |
40 |
sofosbuvir |
0.70 (0.57, 0.87) |
0.91 (0.76, 1.08) |
NA |
GS-331007 |
1.01 (0.96, 1.07) |
0.99 (0.94, 1.03) |
NA |
velpatasvir |
0.44 (0.34, 0.57) |
0.47 (0.37, 0.60) |
NA |
Rifampin |
600 once daily |
400 single dose |
ND |
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 |
ND |
100 single dose |
12 |
velpatasvir |
0.29 (0.23, 0.37) |
0.18 (0.15, 0.22) |
NA |
600 single dose |
ND |
100 single dose |
12 |
velpatasvir |
1.28 (1.05, 1.56) |
1.46 (1.17, 1.83) |
NA |
Tacrolimus |
5 single dose |
400 single dose |
ND |
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, DF =
disoproxil fumarate.
aAll interaction studies conducted in
healthy volunteers.
b Administered as ATRIPLA® (efavirenz, emtricitabine, and
tenofovir DF fixed-dose combination).
c Administered as GENVOYA® (elvitegravir, cobicistat, emtricitabine,
and tenofovir alafenamide fixed-dose combination).
d Administered as STRIBILD® (elvitegravir, cobicistat,
emtricitabine, and tenofovir DF fixed-dose combination).
e EPCLUSA was administered under fasted conditions in the reference
arms. |
No effect on the pharmacokinetic parameters of
sofosbuvir, GS-331007, or velpatasvir was observed with dolutegravir; the
combination of emtricitabine, rilpivirine, and tenofovir DF; emtricitabine;
raltegravir; or tenofovir DF.
Table 6 : Changes in Pharmacokinetic Parameters for
Coadministered Drug in the Presence of Sofosbuvir, Velpatasvir, or EPCLUSAa
Coadminister ed Drug |
Dose of Coadministere d Drug (mg) |
SOF Dose (mg) |
VEL Dose (mg) |
N |
Mean Ratio (90% CI) of Coadministered Drug PK With/Without Sofosbuvir, Velpatasvir, or EPCLUSA. No Effect=1.00 |
Cmax |
AUC |
Cmin |
Atazanavir/ ritonavir + emtricitabine/ tenofovir DFb |
atazanavir 300 once daily |
400 once daily |
100 once daily |
24 |
1.09 (1.00, 1.19) |
1.20 (1.10, 1.31) |
1.39 (1.20, 1.61) |
ritonavir 100 once daily |
0.89 (0.82, 0.97) |
0.97 (0.89, 1.05) |
1.29 (1.15, 1.44) |
emtricitabine 200 once daily |
1.01 (0.96, 1.06) |
1.02 (0.99, 1.04) |
1.06 (1.02, 1.11) |
tenofovir DF 300 once daily |
1.55 (1.43, 1.68) |
1.30 (1.24, 1.36) |
1.39 (1.31, 1.48) |
Atorvastatin |
40 single dose |
400 once daily |
100 once daily |
26 |
1.68 (1.49, 1.89) |
1.54 (1.45, 1.64) |
NA |
Darunavir/ ritonavir + emtricitabine/ tenofovir DFc |
darunavir 800 once daily |
400 once daily |
100 once daily |
29 |
0.90 (0.86, 0.95) |
0.92 (0.87, 0.98) |
0.87 (0.79, 0.95) |
ritonavir 100 once daily |
1.07 (0.97, 1.17) |
1.12 (1.05, 1.19) |
1.09 (1.02, 1.15) |
emtricitabine 200 once daily |
1.05 (1.01, 1.08) |
1.05 (1.02, 1.08) |
1.04 (0.98, 1.09) |
tenofovir DF 300 once daily |
1.55 (1.45, 1.66) |
1.39 (1.33, 1.44) |
1.52 (1.45, 1.59) |
Digoxin |
0.25 single dose |
ND |
100 |
21 |
1.88 (1.71, 2.08) |
1.34 (1.13, 1.60) |
NA |
Efavirenz/ emtricitabine/ tenofovir DFd |
efavirenz 600 once daily |
400 once daily |
100 once daily |
15 |
0.81 (0.74, 0.89) |
0.85 (0.80, 0.91) |
0.90 (0.85, 0.95) |
emtricitabine 200 once daily |
1.07 (0.98, 1.18) |
1.07 (1.00, 1.14) |
1.10 (0.97, 1.25) |
tenofovir DF 300 once daily |
1.77 (1.53, 2.04) |
1.81 (1.68, 1.94) |
2.21 (2.00, 2.43) |
Elvitegravir/ cobicistat/ emtricitabine/ tenofovir alaf!namidee |
elvitegravir 150 once daily |
400 once daily |
100 once daily |
24 |
0.87 (0.80, 0.94) |
0.94 (0.88, 1.00) |
1.08 (0.97, 1.20) |
cobicistat 150 once daily |
1.16 (1.09, 1.23) |
1.30 (1.23, 1.38) |
2.03 (1.67, 2.48) |
emtricitabine 200 once daily |
1.02 (0.97, 1.06) |
1.01 (0.98, 1.04) |
1.02 (0.97, 1.07) |
tenofovir alafenamide 10 once daily |
0.80 (0.68, 0.94) |
0.87 (0.81, 0.94) |
NA |
Elvitegravir/ cobicistat/ emtricitabine/ tenofovir DFf |
elvitegravir 150 once daily |
400 once daily |
100 once daily |
24 |
0.93 (0.86, 1.00) |
0.93 (0.87, 0.99) |
0.97 (0.91, 1.04) |
cobicistat 150 once daily |
1.11 (1.06, 1.17) |
1.23 (1.17, 1.29) |
1.71 (1.54, 1.90) |
emtricitabine 200 once daily |
1.02 (0.97, 1.08) |
1.01 (0.98, 1.04) |
1.06 (1.01, 1.11) |
tenofovir DF 300 once daily |
1.36 (1.25, 1.47) |
1.35 (1.29, 1.42) |
1.45 (1.39, 1.51) |
Emtricitabine/ rilpivirine/ tenofovir DFg |
emtricitabine 200 once daily |
400 once daily |
100 once daily |
24 |
0.95 (0.90, 1.00) |
0.99 (0.97, 1.02) |
1.05 (0.99, 1.11) |
rilpivirine 25 once daily |
0.93 (0.88, 0.98) |
0.95 (0.90, 1.00) |
0.96 (0.90, 1.03) |
tenofovir DF 300 once daily |
1.44 (1.33, 1.55) |
1.40 (1.34, 1.46) |
1.84 (1.76, 1.92) |
Norelgestromin |
norgestimate 0.180/0.215/0.25/ ethinyl estradiol 0.025 once daily |
ND |
100 once daily |
13 |
0.97 (0.88, 1.07) |
0.90 (0.82, 0.98) |
0.92 (0.83, 1.03) |
400 once daily |
ND |
15 |
1.07 (0.94, 1.22) |
1.06 (0.92, 1.21) |
1.07 (0.89, 1.28) |
Norgestrel |
ND |
100 once daily |
13 |
0.96 (0.78, 1.19) |
0.91 (0.73, 1.15) |
0.92 (0.73, 1.18) |
400 once daily |
ND |
15 |
1.18 (0.99, 1.41) |
1.19 (0.98, 1.45) |
1.23 (1.00, 1.51) |
Ethinyl estradiol |
ND |
100 once daily |
12 |
1.39 (1.17, 1.66) |
1.04 (0.87, 1.24) |
0.83 (0.65, 1.06) |
400 once daily |
ND |
15 |
1.15 (0.97, 1.36) |
1.09 (0.94, 1.26) |
0.99 (0.80, 1.23) |
Pravastatin |
40 single dose |
ND |
100 once daily |
18 |
1.28 (1.08, 1.52) |
1.35 (1.18, 1.54) |
NA |
Rosuvastatin |
10 single dose |
ND |
100 once daily |
18 |
2.61 (2.32, 2.92) |
2.69 (2.46, 2.94) |
NA |
Raltegravir + emtricitabine/ tenofovir DF |
emtricitabine 200 once daily |
400 once daily |
100 once daily |
30 |
1.08 (1.04, 1.12) |
1.05 (1.03, 1.07) |
1.02 (0.97, 1.08) |
tenofovir DF 300 once daily |
1.46 (1.39, 1.54) |
1.40 (1.34, 1.45) |
1.70 (1.61, 1.79) |
raltegravir 400 twice daily |
1.03 (0.74, 1.43) |
0.97 (0.73, 1.28) |
0.79 (0.42, 1.48) |
Tacrolimus |
5 single dose |
400 single dose |
ND |
16 |
0.73 (0.59, 0.90) |
1.09 (0.84, 1.40) |
NA |
NA = not available/not applicable, ND = not dosed, DF =
disoproxil fumarate.
a All interaction studies conducted in healthy volunteers.
b Comparison based on exposures when administered as
atazanavir/ritonavir + emtricitabine/tenofovir DF.
c Comparison based on exposures when administered as
darunavir/ritonavir + emtricitabine/tenofovir DF.
d Administered as ATRIPLA (efavirenz, emtricitabine, and tenofovir
DF fixed-dose combination).
e Administered as GENVOYA (elvitegravir, cobicistat, emtricitabine,
and tenofovir alafenamide fixed-dose combination).
f Administered as STRIBILD (elvitegravir, cobicistat, emtricitabine,
and tenofovir DF fixed-dose combination).
g Administered as COMPLERA® (emtricitabine, rilpivirine, and
tenofovir DF fixed-dose combination). |
No effect on the
pharmacokinetic parameters of the following coadministered drugs was observed
with EPCLUSA (dolutegravir or lopinavir/ritonavir) or its components sofosbuvir
(cyclosporine or methadone) or velpatasvir (cyclosporine).
Microbiology
Mechanism 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 genotype 1b, 2a, 3a, and
4a with an IC50 value ranging from 0.36 to 3.3 micromolar. GS-461203 is neither
an inhibitor of human DNA and RNA polymerases nor an inhibitor of mitochondrial
RNA polymerase.
Velpatasvir is an inhibitor of
the HCV NS5A protein, which is required for viral replication. Resistance
selection in cell culture and cross-resistance studies indicate velpatasvir
targets NS5A as its mode of action.
Antiviral Activity
The EC50 values of sofosbuvir
and velpatasvir against full-length or chimeric replicons encoding NS5B and
NS5A sequences from the laboratory strains are presented in Table 7. The EC50 values
of sofosbuvir and velpatasvir against clinical isolates are presented in Table
8.
Table 7 : Activity of Sofosbuvir and Velpatasvir
Against Full Length or Chimeric Laboratory Replicons
Replicon Genotype |
Sofosbuvir EC50, nMa |
Velpatasvir EC50, nMa |
1a |
40 |
0.014 |
1b |
110 |
0.016 |
2a |
50 |
0.005-0.016c |
2b |
15b |
0.002-0.006c |
3a |
50 |
0.004 |
4a |
40 |
0.009 |
4d |
33.4 |
0.004 |
5a |
15b |
0.021-0.054d |
6a |
14-25b |
0.006-0.009 |
6e |
NA |
0.130d |
NA = not available.
a Mean value from multiple experiments of same laboratory
replicon.
b Stable chimeric 1b replicons carrying NS5B genes from genotype 2b,
5a, or 6a were used for testing.
c Data from various strains of full-length NS5A replicons or
chimeric NS5A replicons carrying full-length NS5A genes that contain L31 or M31
polymorphisms.
d Data from a chimeric NS5A replicon carrying NS5A amino acids
9-184. |
Table 8 : Activity of Sofosbuvir and Velpatasvir Against Transient Replicons Containing NS5A or NS5B from Clinical Isolates
Replicon Genotype |
Replicons Containing NS5B from Clinical Isolates |
Replicons Containing NS5A from Clinical Isolates |
Number of clinical isolates |
Median sofosbuvir EC50, nM (range) |
Number of clinical isolates |
Median velpatasvir EC50, nM (range) |
1a |
67 |
62 (29-128) |
23 |
0.019 (0.011-0.078) |
1b |
29 |
102 (45-170) |
34 |
0.012 (0.005-0.500) |
2a |
1 |
28 |
8 |
0.011 (0.006-0.364) |
2b |
14 |
30 (14-81) |
16 |
0.002 (0.0003-0.007) |
3a |
106 |
81 (24-181) |
38 |
0.005 (0.002-1.871) |
4a |
NA |
NA |
5 |
0.002 (0.001-0.004) |
4d |
NA |
NA |
10 |
0.007 (0.004-0.011) |
4r |
NA |
NA |
7 |
0.003 (0.002-0.006) |
5a |
NA |
NA |
42 |
0.005 (0.001-0.019) |
6a |
NA |
NA |
26 |
0.007 (0.0005-0.113) |
6e |
NA |
NA |
15 |
0.024 (0.005-0.433) |
NA = not available. |
Velpatasvir was not
antagonistic in reducing HCV RNA levels in replicon cells when combined with
sofosbuvir or interferon-α, ribavirin, an HCV NS3/4A protease inhibitor,
or HCV NS5B non-nucleoside inhibitors.
Resistance
In Cell Culture
HCV replicons with reduced
susceptibility to sofosbuvir have been selected in cell culture for multiple
genotypes including 1b, 2a, 2b, 3a, 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 2a, 5, and 6 replicons. Site-directed mutagenesis of
the S282T substitution in replicons of genotypes 1 to 6 conferred 2-to 18-fold
reduced susceptibility to sofosbuvir.
HCV genotype 1a, 1b, 2a, 3a,
4a, 5a, and 6a replicon variants with reduced susceptibility to velpatasvir
were selected in cell culture. Variants developed amino acid substitutions at
NS5A resistance-associated positions 24, 28, 30, 31, 32, 58, 92, and 93.
Phenotypic analysis of site-directed mutant replicons of the selected NS5A
substitutions showed that single and double combinations of L31V and Y93H/N in
genotype 1a, the combination of L31V + Y93H in genotype 1b, Y93H/S in genotype
3a, and L31V and P32A/L/Q/R in genotype 6 conferred greater than 100-fold
reduction in velpatasvir susceptibility. In the genotype 2a replicon, the
single mutants F28S and Y93H showed 91-fold and 46-fold reduced susceptibility
to velpatasvir, respectively. The single mutant Y93H conferred 3-fold reduced
susceptibility to velpatasvir in genotype 4a replicons. Combinations of these
NS5A substitutions often showed greater reductions in susceptibility to
velpatasvir than single substitutions alone.
In Clinical Trials
Studies In Subjects Without Cirrhosis
And Subjects With Compensated Cirrhosis
In a pooled analysis of
subjects without cirrhosis or with compensated cirrhosis who received EPCLUSA
for 12 weeks in Phase 3 trials (ASTRAL-1, ASTRAL-2, and ASTRAL-3), 12 subjects
(2 with genotype 1 [1a, 1c/h] and 10 with genotype 3a) qualified for resistance
analysis due to virologic failure. No subjects with genotype 2, 4, 5, or 6 HCV
infection experienced virologic failure.
Of the 2 genotype 1 virologic
failure subjects, 1 subject had virus with emergent NS5A resistance
substitution Y93N and the other had virus with emergent NS5A resistance
substitutions Y93H and low-level K24M/T and L31I/V at virologic failure. The
latter subject had genotype 1c/h virus at baseline harboring NS5A resistance
polymorphisms (Q30R, L31M, H58P) relative to genotype 1a. No sofosbuvir NS5B
nucleoside analog resistance-associated substitutions were observed at failure
in the 2 subjects.
Of the 10 genotype 3a virologic
failure subjects, NS5A resistance substitution Y93H was observed in all 10
subjects at failure (7 subjects had Y93H emerge post-treatment and 3 subjects
had Y93H at baseline and post-treatment). Treatment-emergent sofosbuvir NS5B
substitutions L314F (n=2) and L314I (n=1) were observed at high frequency
(greater than or equal to 15%) in the NS5B polymerase in 3 genotype 3a subjects
who relapsed: one in the EPCLUSA group and two in the sofosbuvir plus ribavirin
24-week group. In addition, low frequency (less than 4%) treatment-emergent
L314P was detected in 2 genotype 3a subjects who relapsed, including one
subject in the sofosbuvir plus ribavirin 24-week group in ASTRAL-3 and
one in the EPCLUSA group in ASTRAL-4. The clinical significance of this
substitution is unknown.
Studies In Subjects With Decompensated Cirrhosis
In the ASTRAL-4 trial in subjects with decompensated
cirrhosis who received EPCLUSA with ribavirin for 12 weeks, 3 subjects (1 with
genotype 1a and 2 with genotype 3a) qualified for resistance analysis due to
virologic failure. No subjects with genotype 2 or 4 HCV infection who received
EPCLUSA with ribavirin for 12 weeks experienced virologic failure.
The genotype 1 virologic failure subject had no NS5A or
NS5B resistance substitutions at failure.
The 2 genotype 3a virologic failure subjects had the NS5A
resistance substitutions Y93H and either low-level M28V or S38P emerge at
failure. One of these subjects also developed low levels (less than 5%) of NS5B
nucleoside analog inhibitor resistance substitutions N142T and E237G at
failure.
In the ASTRAL-4 trial, 2 subjects treated with EPCLUSA
for 12 or 24 weeks without ribavirin had emergent sofosbuvir NS5B
resistance-associated substitutions S282T at low levels (less than 5%) along
with L159F. EPCLUSA for 12 or 24 weeks without ribavirin is not recommended in
patients with decompensated cirrhosis.
Persistence Of Resistance-Associated Substitutions
No data are available on the persistence of sofosbuvir or
velpatasvir resistance-associated substitutions. NS5A resistance-associated
substitutions observed with administration of other NS5A inhibitors have been
found to persist for longer than 1 year in most patients. The long-term
clinical impact of the emergence or persistence of virus containing sofosbuvir
or velpatasvir resistance-associated substitutions is unknown.
Effect Of Baseline HCV Polymorphisms On Treatment Response
Analyses were conducted to explore the association
between relapse rates and preexisting baseline NS5A resistance-associated
polymorphisms (RAPs) (any change from reference at NS5A amino acid positions
24, 28, 30, 31, 58, 92, or 93) identified by population or deep sequencing
analysis at a sensitivity threshold of 15% or higher for subjects without
cirrhosis or with compensated cirrhosis in ASTRAL-1, ASTRAL-2, and ASTRAL-3 and
subjects with decompensated cirrhosis in ASTRAL-4.
Studies In Subjects Without Cirrhosis And Subjects With
Compensated Cirrhosis
Among the subjects who received treatment with EPCLUSA
for 12 weeks, 18% (37/209), 32% (38/117), 64% (149/232), 20% (56/274), 63%
(73/115), 9% (3/34), and 83% (35/42) of subjects with genotype 1a, 1b, 2, 3, 4,
5, and 6 HCV, respectively, had baseline virus with NS5A RAPs.
Genotype 1
Among the 75 genotype 1 subjects who had baseline NS5A
RAPs, one subject (1%) with Q30R, L31M and H58P polymorphisms at baseline and
compensated cirrhosis relapsed.
Genotype 3
Among the 56 genotype 3 subjects who had baseline NS5A
RAPs, 4 subjects (7%) relapsed (3 with baseline Y93H and 1 with baseline A30K).
Overall, 20% (3/15) of genotype 3 subjects with the Y93H polymorphism at
baseline relapsed.
For genotype 3 subjects with compensated cirrhosis,
relapse rates were 33% (3/9) for subjects with baseline NS5A RAPs compared to
6% (4/71) for subjects without baseline NS5A RAPs.
Genotypes 2, 4, 5, And 6
The presence of baseline NS5A RAPs did not affect relapse
rates for subjects with genotypes 2, 4, 5, and 6, because all achieved SVR12.
SVR12 was achieved in all 77 subjects who had baseline
NS5B nucleoside analog inhibitor resistance polymorphisms including N142T,
L159F, E/N237G, C/M289L/I, L320F/I/V, V321A/I, and S282G + V321I. The
sofosbuvir NS5B nucleoside analog inhibitor resistance substitution S282T was
not detected in the baseline NS5B sequence of any subject using 1% deep sequencing
cutoff in Phase 3 trials.
Studies In Subjects With Decompensated Cirrhosis
In ASTRAL-4, the prevalence of NS5A RAPs at baseline was
24% (48/198), 60% (6/10), 11% (4/37), and 63% (5/8) in GT1, GT2, GT3, and GT4
HCV subjects, respectively. No subjects with genotypes 2, 4 and 6 relapsed.
There were no subjects with genotype 5 in this trial.
For genotype 1 subjects, the overall relapse rates were
numerically lower for the 12-week EPCLUSA with ribavirin group (2%; 1/66)
compared to EPCLUSA 12-week and 24-week treatment groups. For subjects with
NS5A RAPs, relapse rates were 0% (0/17) compared to 2% (1/49) for subjects
without NS5A RAPs in the 12-week EPCLUSA with ribavirin containing group.
For genotype 3 subjects, overall virologic failure rates
were numerically lower for the 12-week EPCLUSA with ribavirin group (15%; 2/13)
compared to EPCLUSA 12-week and 24-week treatment groups. There are
insufficient data to determine the impact of HCV NS5A RAPs in genotype 3
subjects with decompensated cirrhosis.
Three subjects in the EPCLUSA with ribavirin 12-week
group had baseline NS5B nucleoside analog inhibitor polymorphisms (N142T and
L159F) using 1% deep sequencing cutoff and all 3 subjects achieved SVR12.
Cross Resistance
Both sofosbuvir and velpatasvir 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 EPCLUSA 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
Table 9 presents the clinical trial design including
different treatment groups that were conducted with EPCLUSA with and without
ribavirin in subjects with chronic hepatitis C (HCV) genotype 1, 2, 3, 4, 5,
and 6 infection. For detailed description of trial design and recommended
regimen and duration [see DOSAGE AND ADMINISTRATION and Clinical
Studies].
Table 9 : Trials Conducted with EPCLUSA in Subjects
with Genotype 1, 2, 3, 4, 5, or 6 HCV Infection
Trial |
Population |
EPCLUSA and Comparator Groups (Number of Subjects Treated) |
ASTRAL-1 |
Genotype 1, 2, 4, 5, and 6 TN and TE, without cirrhosis or with compensated cirrhosis |
EPCLUSA 12 weeks (624) Placebo 12 weeks (116) |
ASTRAL-2 |
Genotype 2 TN and TE, without cirrhosis or with compensated cirrhosis |
EPCLUSA 12 weeks (134) SOF + RBV 12 weeks (132) |
ASTRAL-3 |
Genotype 3 TN and TE, without cirrhosis or with compensated cirrhosis |
EPCLUSA 12 weeks (277) SOF + RBV 24 weeks (275) |
ASTRAL-4 |
Genotype 1, 2, 3, 4, 5, and 6 TN and TE, with CP class B decompensated cirrhosis |
EPCLUSA 12 weeks (90) EPCLUSA + RBV 12 weeks (87) EPCLUSA 24 weeks (90) |
ASTRAL-5 |
Genotype 1, 2, 3, 4, 5, and 6 HCV/HIV-1 coinfected TN and TE, without cirrhosis or with compensated cirrhosis |
EPCLUSA 12 weeks (106) |
TN = treatment-naíve subjects;
TE = treatment-experienced subjects are those who have failed a peginterferon
alfa/ribavirin based regimen with or without an HCV protease inhibitor
(boceprevir, simeprevir, or telaprevir); SOF = sofosbuvir; RBV = ribavirin; CP
= Child-Pugh. |
The ribavirin dosage was
weight-based (1000 mg daily administered in two divided doses for subjects less
than 75 kg and 1200 mg for those greater than or equal to 75 kg) and
administered in two divided doses when used in combination with sofosbuvir in
the ASTRAL-2 and ASTRAL-3 trials or in combination with EPCLUSA in the ASTRAL-4
trial. Ribavirin dosage adjustments were performed according to the ribavirin
prescribing information. Serum HCV RNA values were measured during the clinical
trials using the COBAS AmpliPrep/COBAS Taqman HCV test (version 2.0) with a
lower limit of quantification (LLOQ) of 15 IU/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 all the trials. Relapse is defined as
HCV RNA greater than or equal to LLOQ during the post-treatment period after
having achieved HCV RNA less than LLOQ at the end of treatment. On-treatment
virologic failure is defined as breakthrough, rebound, or non-response.
Clinical Trials In Subjects Without Cirrhosis And Subjects
With Compensated Cirrhosis
Genotype 1, 2, 4, 5, And 6 HCV
Infected Adults (ASTRAL-1)
ASTRAL-1 was a randomized,
double-blind, placebo-controlled trial that evaluated 12 weeks of treatment with
EPCLUSA compared with 12 weeks of placebo in subjects with genotype 1, 2, 4, 5,
or 6 HCV infection without cirrhosis or with compensated cirrhosis. Subjects
with genotype 1, 2, 4, or 6 HCV infection were randomized in a 5:1 ratio to
treatment with EPCLUSA or placebo for 12 weeks. Subjects with genotype 5 HCV
infection were enrolled to the EPCLUSA group. Randomization was stratified by
HCV genotype (1, 2, 4, 6, and indeterminate) and the presence or absence of
compensated cirrhosis.
Demographics and baseline characteristics were balanced
between the EPCLUSA and placebo group. Of the 740 treated subjects, the median
age was 56 years (range: 18 to 82); 60% of the subjects were male; 79% were
White, 9% were Black; 21% had a baseline body mass index at least 30 kg/m²; the
proportions of subjects with genotype 1, 2, 4, 5, or 6 HCV infection were 53%,
17%, 19%, 5%, and 7%, respectively; 69% had non-CC IL28B alleles (CT or TT);
74% had baseline HCV RNA levels at least 800,000 IU/mL; 19% had compensated
cirrhosis; and 32% were treatment-experienced.
Table 10 presents SVR12 and other virologic outcomes in
EPCLUSA-treated subjects in the ASTRAL-1 trial by HCV genotype. No subjects in
the placebo group achieved SVR12.
Table 10 : Study ASTRAL-1: Virologic Outcomes by HCV
Genotype in EPCLUSA-Treated Subjects without Cirrhosis or with Compensated
Cirrhosis (12 Weeks After Treatment)
|
EPCLUSA 12 Weeks
(N=624) |
Total (all GTs)
(N=624) |
GT-1 |
GT-2
(N=104) |
GT-4
(N=116) |
GT-5
(N=35) |
GT-6
(N=41) |
GT-1a
(N=210) |
GT-1b
(N=118) |
Total
(N=328) |
SVR12 |
99% (618/624) |
98% (206/210) |
99% (117/118) |
98% (323/328) |
100% (104/104) |
100% (116/116) |
97% (34/35) |
100% (41/41) |
Outcome for Subjects without SVR |
On-Treatment Virologic Failure |
0/624 |
0/210 |
0/118 |
0/328 |
0/104 |
0/116 |
0/35 |
0/41 |
Relapsea |
<1% (2/623) |
<1% (1/209) |
1% (1/118) |
1% (2/327) |
0/104 |
0/116 |
0/35 |
0/41 |
Otherb |
1% (4/624) |
1% (3/210) |
0/118 |
1% (3/328) |
0/104 |
0/116 |
3% (1/35) |
0/41 |
GT = genotype; no subjects in the placebo group achieved
SVR12.
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. |
Genotype 2 HCV Infected Adults (ASTRAL-2)
ASTRAL-2 was a randomized,
open-label trial that evaluated 12 weeks of treatment with EPCLUSA compared
with 12 weeks of treatment with SOF with ribavirin in subjects with genotype 2
HCV infection. Subjects were randomized in a 1:1 ratio to the treatment groups.
Randomization was stratified by the presence or absence of compensated
cirrhosis and prior treatment experience (treatment-naíve vs
treatment-experienced).
Demographics and baseline characteristics were balanced
across the two treatment groups. Of the 266 treated subjects, the median age
was 58 years (range: 23 to 81); 59% of the subjects were male; 88% were White;
7% were Black; 33% had a baseline body mass index at least 30 kg/m²; 62% had
non-CC IL28B alleles (CT or TT); 80% had baseline HCV RNA levels at least
800,000 IU/mL; 14% had compensated cirrhosis; and 15% were
treatment-experienced.
Table 11 presents SVR12 and other virologic outcomes from
the ASTRAL-2 trial.
Table 11 : Study ASTRAL-2: Virologic Outcomes in
Subjects with Genotype 2 HCV without Cirrhosis or with Compensated Cirrhosis
(12 Weeks After Treatment)
|
EPCLUSA 12 Weeks
(N=134) |
SOF + RBV 12 Weeks
(N=132) |
SVR12 |
99% (133/134) |
94% (124/132) |
|
Treatment difference +5.2%; 95% confidence interval (+0.2% to +10.3%) |
Outcome for subjects without SVR |
On-Treatment Virologic Failure |
0/134 |
0/132 |
Relapsea |
0/133 |
5% (6/132) |
Otherb |
1% (1/134) |
2% (2/132) |
SOF = sofosbuvir; RBV = ribavirin.
a The denominator for relapse is the number of subjects with HCV RNA
<LLOQ at the last on-treatment assessment.
b Other includes subjects who did not achieve SVR12 and did not meet
virologic failure criteria. |
Genotype 3 HCV Infected Adults (ASTRAL-3)
ASTRAL-3 was a randomized,
open-label trial that evaluated 12 weeks of treatment with EPCLUSA compared
with 24 weeks of treatment with SOF with ribavirin in subjects with genotype 3
HCV infection. Subjects were randomized in a 1:1 ratio to the treatment groups.
Randomization was stratified by the presence or absence of compensated
cirrhosis and prior treatment experience (treatment-naíve vs
treatment-experienced).
Demographics and baseline characteristics were balanced
across the treatment groups. Of the 552 treated subjects, the median age was 52
years (range: 19 to 76); 62% of the subjects were male; 89% were White; 9% were
Asian; 20% had a baseline body mass index at least 30 kg/m²; 61% had non-CC
IL28B alleles (CT or TT); 70% had baseline HCV RNA levels at least 800,000
IU/mL; 30% had compensated cirrhosis; and 26% were treatment-experienced.
Table 12 presents SVR12 and
other virologic outcomes from the ASTRAL-3 trial.
Table 12 : Study ASTRAL-3:
Virologic Outcomes in Subjects with Genotype 3 HCV without Cirrhosis or with
Compensated Cirrhosis (12 Weeks After Treatment)
|
EPCLUSA 12 Weeks
(N=277) |
SOF + RBV 24 Weeks
(N=275) |
SVR12 |
95% (264/277) |
80% (221/275) |
|
Treatment difference +14.8%; 95% confidence interval (+9.6% to +20.0%) |
Outcome for subjects without SVR |
On-Treatment Virologic Failure |
0/277 |
<1% (1/275) |
Relapsea |
4% (11/276) |
14% (38/272) |
Otherb |
1% (2/277) |
5% (15/275) |
SOF = sofosbuvir; RBV =
ribavirin.
a The denominator for relapse is the number of subjects with
HCV RNA <LLOQ at the last on-treatment assessment.
b Other includes subjects who did not achieve SVR and did not meet
virologic failure criteria. |
SVR12 for selected subgroups are presented in Table 13.
Table 13 : Study ASTRAL-3:
SVR12 by Prior Treatment and Presence/Absence of Compensated Cirrhosis in
Subjects with Genotype 3 HCV
|
EPCLUSA 12 Weeks |
SOF + RBV 24 Weeksa |
Treatment-Naive
(N=206) |
Treatment- Experienced
(N=71) |
Treatment-Naive
(N=201) |
Treatment- Experienced
(N=69) |
Without cirrhosis |
98% (160/163) |
94% (31/33)b |
90% (141/156) |
71% (22/31) |
With compensated cirrhosis |
93% (40/43) |
89% (33/37) |
73% (33/45) |
58% (22/38) |
SOF = sofosbuvir; RBV = ribavirin.
a Five subjects with missing cirrhosis status in the SOF + RBV
24-week group were excluded from this subgroup analysis.
b One treatment-experienced subject without cirrhosis treated with
EPCLUSA had genotype 1a HCV infection at failure, indicating HCV re-infection,
and is therefore excluded from this analysis. |
Clinical Trial In Subjects Coinfected With HCV And HIV-1
ASTRAL-5 was an open-label
trial that evaluated 12 weeks of treatment with EPCLUSA in subjects with
genotype 1, 2, 3, 4, 5 or 6 HCV infection who were coinfected with HIV1.
Subjects were on a stable HIV-1 antiretroviral therapy that included
emtricitabine/tenofovir disoproxil fumarate or abacavir/lamivudine administered
with atazanavir/ritonavir, darunavir/ritonavir, lopinavir/ritonavir,
rilpivirine, raltegravir or elvitegravir/cobicistat.
Of the 106 treated subjects, the median age was 57 years
(range: 25 to 72); 86% of the subjects were male; 51% were White; 45% were
Black; 22% had a baseline body mass index at least 30 kg/m²; the proportions of
patients with genotype 1, 2, 3, or 4 HCV infection were 74%; 10%; 11%, and 5%
respectively; no subjects with genotype 5 or 6 HCV were treated with EPCLUSA;
77% had non-CC IL28B alleles (CT or TT); 74% had baseline HCV RNA levels of at
least 800,000 IU/mL; 18% had compensated cirrhosis; and 29% were treatment
experienced. The overall mean CD4+ count was 598 cells/μL (range:
183-1513 cells/μL) and 57% of subjects had CD4+ counts > 500
cells/μL.
Table 14 presents the SVR12 for
the ASTRAL-5 trial by HCV genotype.
Table 14 : Study ASTRAL-5: Virologic Outcomes by HCV
Genotype in Subjects Coinfected with HIV-1 without Cirrhosis or with
Compensated Cirrhosis (12 Weeks After Treatment)
|
EPCLUSA 12 Weeks
(N=106) |
Total (all GTs)
(N=106) |
GT-1 |
GT-2
(N=11) |
GT-3
(N=12) |
GT-4
(N=5) |
GT-1a
(N=66) |
GT-1b
(N=12) |
Total
(N=78) |
SVR12 |
95% (101/106) |
95% (63/66) |
92% (11/12) |
95% (74/78) |
100% (11/11) |
92% (11/12) |
100% (5/5) |
Outcome for Subjects without SVR |
On-Treatment Virologic Failure |
0/106 |
0/66 |
0/12 |
0/78 |
0/11 |
0/12 |
0/5 |
Relapsea |
2% (2/103) |
3% (2/65) |
0/11 |
3% (2/76) |
0/11 |
0/11 |
0/5 |
Otherb |
3% (3/106) |
2% (1/66) |
8% (1/12) |
3% (2/78) |
0/11 |
8% (1/12) |
(0/5) |
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.
No subject had HIV-1 rebound during treatment and
CD4+ counts were stable during treatment. |
Clinical Trials In Subjects With
Decompensated Cirrhosis
ASTRAL-4 was a randomized,
open-label trial in subjects with genotype 1, 2, 3, 4, 5, or 6 HCV infection
and Child-Pugh B cirrhosis at screening. Subjects were randomized in a 1:1:1
ratio to treatment with EPCLUSA for 12 weeks (N=90), EPCLUSA with ribavirin for
12 weeks (N=87), or EPCLUSA for 24 weeks (N=90). Randomization was stratified
by HCV genotype (1, 2, 3, 4, 5, 6, and indeterminate).
Demographics and baseline characteristics were balanced
across the treatment groups. Of the 267 treated subjects, the median age was 59
years (range: 40 to 73); 70% of the subjects were male; 90% were White, 6% were
Black; 42% had a baseline body mass index at least 30 kg/m². The proportions of
subjects with genotype 1, 2, 3, 4, or 6 HCV were 78%, 4%, 15%, 3%, and less
than 1% (1 subject), respectively. No subjects with genotype 5 HCV infection
were enrolled. 76% had non-CC IL28B alleles (CT or TT); 56% had baseline HCV
RNA levels at least 800,000 IU/mL; 55% were treatment-experienced; and 95% of
subjects had Model for End Stage Liver Disease (MELD) score less than or equal
to 15 at baseline. Although all subjects had Child-Pugh B cirrhosis at
screening, 6% and 4% of subjects were assessed to have Child-Pugh A and
Child-Pugh C cirrhosis, respectively, on the first day of treatment.
Treatment with EPCLUSA with
ribavirin for 12 weeks resulted in numerically higher SVR12 rates than
treatment with EPCLUSA for 12 weeks or 24 weeks. Because EPCLUSA with
ribavirin for 12 weeks is the recommended dosage regimen, the results of the
12-and 24-week EPCLUSA treatment groups are not presented.
Table 15 presents the SVR12 for subjects treated with
EPCLUSA with ribavirin for 12 weeks in the ASTRAL-4 trial by HCV genotype. No
subjects with genotype 5 or 6 HCV were treated with EPCLUSA with ribavirin for
12 weeks.
Table 15 : Study ASTRAL-4: Virologic Outcomes in
Subjects with Decompensated Cirrhosis After 12 Weeks of Treatment by HCV
Genotype
|
EPCLUSA + RBV 12 Weeks
(N=87) |
SVR12 |
Virologic Failure (relapse and on-treatment failure) |
Overall SVR12a |
94% (82/87) |
3% (3/87) |
Genotype 1 |
96% (65/68) |
1% (1/68)b |
Genotype 1a |
94% (51/54) |
2% (1/54)b |
Genotype 1b |
100% (14/14) |
0% (0/14) |
Genotype 3 |
85% (11/13) |
15% (2/13)c |
RBV = ribavirin.
a Includes subjects with baseline CPT C cirrhosis: all 4 subjects
achieved SVR12.
b This subject with genotype 1a experienced relapse.
cOne subject had on-treatment virologic failure; pharmacokinetic
data from this subject was consistent with non-adherence. |
All subjects with genotype 2
(N=4) and genotype 4 (N=2) HCV infection treated with EPCLUSA and ribavirin
achieved SVR12.