Drug Interaction Studies
Ledipasvir and sofosbuvir are substrates of drug transporters P-gp and BCRP while GS-331007 is not. P-gp inducers (e.g., rifampin or St. John's wort) may decrease ledipasvir and sofosbuvir plasma concentrations, leading to reduced therapeutic effect of ledipasvir and sofosbuvir, and the use with P-gp inducers is not recommended with ledipasvir and sofosbuvir [see Warnings and Precautions (5.3)]. Coadministration with drugs that inhibit P-gp and/or BCRP may increase ledipasvir and sofosbuvir plasma concentrations without increasing GS-331007 plasma concentration; ledipasvir and sofosbuvir may be coadministered with P-gp and/or BCRP inhibitors. Neither ledipasvir nor sofosbuvir is a substrate for hepatic uptake transporters OCT1, OATP1B1, or OATP1B3. GS-331007 is not a substrate for renal transporters, including organic anion transporter OAT1 or OAT3, or organic cation transporter OCT2.
Ledipasvir is subject to slow oxidative metabolism via an unknown mechanism. In vitro, no detectable metabolism of ledipasvir by CYP enzymes has been observed. Biliary excretion of unchanged ledipasvir is a major route of elimination. Sofosbuvir is not a substrate for CYP and UGT1A1 enzymes. Clinically significant drug interactions with ledipasvir and sofosbuvir mediated by CYP or UGT1A1 enzymes are not expected.
The effects of coadministered drugs on the exposure of ledipasvir, sofosbuvir, and GS-331007 are shown in Table 8 [see Drug Interactions (7)].
Table 8 Drug Interactions: Changes in Pharmacokinetic Parameters for Ledipasvir, Sofosbuvir, and the Predominant Circulating Metabolite GS-331007 in the Presence of the Coadministered Drug
| Coadministered Drug | Dose of Coadministered Drug (mg) | Ledipasvir Dose (mg) | Sofosbuvir Dose (mg) | N | Mean Ratio (90% CI) of Ledipasvir, Sofosbuvir, and GS-331007 PK With/Without Coadministered Drug No Effect=1.00 |
|---|
| Cmax
| AUC | Cmin
|
|---|
NA = not available/not applicable, ND = not dosed. tenofovir DF = tenofovir disoproxil fumarate |
| Atazanavir/ ritonavir + emtricitabine/ tenofovir DF
,
| 300/100 + 200/300 once daily | 90 once daily | 400 once daily | 24 | ledipasvir | 1.68 (1.54, 1.84) | 1.96 (1.74, 2.21) | 2.18 (1.91, 2.50) |
| sofosbuvir | 1.01 (0.88, 1.15) | 1.11 (1.02, 1.21) | NA |
| GS-331007 | 1.17 (1.12, 1.23) | 1.31 (1.25, 1.36) | 1.42 (1.34, 1.49) |
| Carbamazepine | 300 twice daily | ND | 400 single dose | 24 | sofosbuvir | 0.52 (0.43, 0.62) | 0.52 (0.46, 0.59) | NA |
| GS-331007 | 1.04 (0.97, 1.11) | 0.99 (0.94, 1.04) | NA |
| Cyclosporine | 600 single dose | ND | 400 single dose | 19 | sofosbuvir | 2.54 (1.87, 3.45) | 4.53 (3.26, 6.30) | NA |
| GS-331007 | 0.60 (0.53, 0.69) | 1.04 (0.90, 1.20) | NA |
| Darunavir/ ritonavir | 800/100 once daily | 90 once daily | ND | 23 | ledipasvir | 1.45 (1.34, 1.56) | 1.39 (1.28, 1.49) | 1.39 (1.29, 1.51) |
| ND | 400 single dose | 18 | sofosbuvir | 1.45 (1.10, 1.92) | 1.34 (1.12, 1.59) | NA |
| GS-331007 | 0.97 (0.90, 1.05) | 1.24 (1.18, 1.30) | NA |
| Darunavir/ ritonavir + emtricitabine/ tenofovir DF
| 800/100 + 200/300 once daily | 90 once daily | 400 once daily | 23 | ledipasvir | 1.11 (0.99, 1.24) | 1.12 (1.00, 1.25) | 1.17 (1.04, 1.31) |
| sofosbuvir | 0.63 (0.52, 0.75) | 0.73 (0.65, 0.82) | NA |
| GS-331007 | 1.10 (1.04, 1.16) | 1.20 (1.16, 1.24) | 1.26 (1.20, 1.32) |
| Efavirenz/ emtricitabine/ tenofovir DF
| 600/200/300 once daily | 90 once daily | 400 once daily | 14 | ledipasvir | 0.66 (0.59, 0.75) | 0.66 (0.59, 0.75) | 0.66 (0.57, 0.76) |
| sofosbuvir | 1.03 (0.87, 1.23) | 0.94 (0.81, 1.10) | NA |
| GS-331007 | 0.86 (0.76, 0.96) | 0.90 (0.83, 0.97) | 1.07 (1.02, 1.13) |
| Elvitegravir/ cobicistat/ emtricitabine/ tenofovir alafenamide | 150/150/200/10 once daily | 90 once daily | 400 once daily | 30 | ledipasvir | 1.65 (1.53, 1.78) | 1.79 (1.64, 1.96) | 1.93 (1.74, 2.15) |
| sofosbuvir | 1.28 (1.13, 1.47) | 1.47 (1.35, 1.59) | NA |
| GS-331007 | 1.29 (1.24, 1.35) | 1.48 (1.44, 1.53) | 1.66 (1.60, 1.73) |
| Famotidine | 40 single dose simultaneously with ledipasvir and sofosbuvir tablets | 90 single dose | 400 single dose | 12 | ledipasvir | 0.80 (0.69, 0.93) | 0.89 (0.76, 1.06) | NA |
| sofosbuvir | 1.15 (0.88, 1.50) | 1.11 (1.00, 1.24) | NA |
| GS-331007 | 1.06 (0.97, 1.14) | 1.06 (1.02, 1.11) | NA |
| 40 single dose 12 hours prior to ledipasvir and sofosbuvir tablets | 12 | ledipasvir | 0.83 (0.69, 1.00) | 0.98 (0.80, 1.20) | NA |
| sofosbuvir | 1.00 (0.76, 1.32) | 0.95 (0.82, 1.10) | NA |
| GS-331007 | 1.13 (1.07, 1.20) | 1.06 (1.01, 1.12) | NA |
| Methadone | 30 to 130 daily | ND | 400 once daily | 14 | sofosbuvir | 0.95 (0.68, 1.33) | 1.30 (1.00, 1.69) | NA |
| GS-331007 | 0.73 (0.65, 0.83) | 1.04 (0.89, 1.22) | NA |
| Omeprazole | 20 once daily simultaneously with ledipasvir and sofosbuvir tablets | 90 single dose | 400 single dose | 16 | ledipasvir | 0.89 (0.61, 1.30) | 0.96 (0.66, 1.39) | NA |
| sofosbuvir | 1.12 (0.88, 1.42) | 1.00 (0.80, 1.25) | NA |
| GS-331007 | 1.14 (1.01, 1.29) | 1.03 (0.96, 1.12) | NA |
| 20 once daily 2 hours prior to ledipasvir | 30 single dose | ND | 17 | ledipasvir | 0.52 (0.41, 0.66) | 0.58 (0.48, 0.71) | NA |
| Rifabutin | 300 once daily | ND | 400 single dose | 20 | sofosbuvir | 0.64 (0.53, 0.77) | 0.76 (0.63, 0.91) | NA |
| GS-331007 | 1.15 (1.03, 1.27) | 1.03 (0.95, 1.12) | NA |
| Rifampin | 600 once daily | 90 single dose
| ND | 31 | ledipasvir | 0.65 (0.56, 0.76) | 0.41 (0.36, 0.48) | NA |
| ND | 400 single dose | 17 | sofosbuvir | 0.23 (0.19, 0.29) | 0.28 (0.24, 0.32) | NA |
| GS-331007 | 1.23 (1.14, 1.34) | 0.95 (0.88, 1.03) | NA |
| Simeprevir | 150 once daily | 30 once daily | ND | 22 | ledipasvir | 1.81 (1.69, 2.94) | 1.92 (1.77, 2.07) | NA |
| Tacrolimus | 5 single dose | ND | 400 single dose | 16 | sofosbuvir | 0.97 (0.65, 1.43) | 1.13 (0.81, 1.57) | NA |
| GS-331007 | 0.97 (0.83, 1.14) | 1.00 (0.87, 1.13) | NA |
No effect on the pharmacokinetic parameters of ledipasvir, sofosbuvir, and GS-331007 was observed with raltegravir and the combination of abacavir and lamivudine; emtricitabine, rilpivirine, and tenofovir disoproxil fumarate; or dolutegravir, emtricitabine, and tenofovir disoproxil fumarate.
Ledipasvir is an inhibitor of drug transporter P-gp and breast cancer resistance protein (BCRP) and may increase intestinal absorption of coadministered substrates for these transporters. Ledipasvir is an inhibitor of transporters OATP1B1, OATP1B3, and BSEP only at concentrations exceeding those achieved in clinic. Ledipasvir is not an inhibitor of transporters MRP2, MRP4, OCT2, OAT1, OAT3, MATE1, and OCT1. The drug-drug interaction potential of ledipasvir is primarily limited to the intestinal inhibition of P-gp and BCRP. Clinically relevant transporter inhibition by ledipasvir in the systemic circulation is not expected due to its high protein binding. Sofosbuvir and GS-331007 are not inhibitors of drug transporters P-gp, BCRP, MRP2, BSEP, OATP1B1, OATP1B3, and OCT1, and GS-331007 is not an inhibitor of OAT1, OCT2, and MATE1. Ledipasvir, sofosbuvir, and GS-331007 are not inhibitors or inducers of CYP or UGT1A1 enzymes.
The effects of ledipasvir or sofosbuvir on the exposure of coadministered drugs are shown in Table 9 [see Drug Interactions (7)].
Table 9 Drug Interactions: Changes in Pharmacokinetic Parameters for Coadministered Drug in the Presence of Ledipasvir, Sofosbuvir, or Ledipasvir and Sofosbuvir
| Coadministered Drug | Dose of Coadministered Drug (mg) | Ledipasvir Dose (mg) | Sofosbuvir Dose (mg) | N | Mean Ratio (90% CI) of Coadministered Drug PK With/Without Ledipasvir, Sofosbuvir, or Ledipasvir and Sofosbuvir No Effect=1.00 |
|---|
| Cmax
| AUC | Cmin
|
|---|
NA = not available/not applicable, ND = not dosed. tenofovir DF = tenofovir disoproxil fumarate |
| Atazanavir/ ritonavir + emtricitabine /tenofovir DF
,
,
| atazanavir 300 once daily | 90 once daily | 400 once daily | 24 | 1.07 (0.99, 1.14) | 1.27 (1.18, 1.37) | 1.63 (1.45, 1.84) |
| ritonavir 100 once daily | 0.86 (0.79, 0.93) | 0.97 (0.89, 1.05) | 1.45 (1.27, 1.64) |
| tenofovir DF 300 once daily | 1.47 (1.37, 1.58) | 1.35 (1.29, 1.42) | 1.47 (1.38, 1.57) |
| Darunavir/ ritonavir + emtricitabine/ tenofovir DF
,
| darunavir 800 once daily | 90 once daily | 400 once daily | 23 | 1.01 (0.96, 1.06) | 1.04 (0.99, 1.08) | 1.08 (0.98, 1.20) |
| ritonavir 100 once daily | 1.17 (1.01, 1.35) | 1.25 (1.15, 1.36) | 1.48 (1.34, 1.63) |
| tenofovir DF 300 once daily | 1.64 (1.54, 1.74) | 1.50 (1.42, 1.59) | 1.59 (1.49, 1.70) |
| Elvitegravir/ cobicistat/ emtricitabine/ tenofovir alafenamide | elvitegravir 150 once daily | 90 once daily | 400 once daily | 30 | 0.98 (0.90, 1.07) | 1.11 (1.02, 1.20) | 1.46 (1.28, 1.66) |
| cobicistat 150 once daily | 1.23 (1.15, 1.32) | 1.53 (1.45, 1.62) | 3.25 (2.88, 3.67) |
| tenofovir alafenamide 10 once daily | 0.90 (0.73, 1.11) | 0.86 (0.78, 0.95) | NA |
| Norelgestromin | norgestimate 0.180/0.215/0.25/ethinyl estradiol 0.025 once daily | 90 once daily | ND | 15 | 1.02 (0.89, 1.16) | 1.03 (0.90, 1.18) | 1.09 (0.91, 1.31) |
| ND | 400 once daily | 1.07 (0.94, 1.22) | 1.06 (0.92, 1.21) | 1.07 (0.89, 1.28) |
| Norgestrel | 90 once daily | ND | 1.03 (0.87, 1.23) | 0.99 (0.82, 1.20) | 1.00 (0.81, 1.23) |
| ND | 400 once daily | 1.18 (0.99, 1.41) | 1.19 (0.98, 1.45) | 1.23 (1.00, 1.51) |
| Ethinyl estradiol | 90 once daily | ND | 1.40 (1.18, 1.66) | 1.20 (1.04, 1.39) | 0.98 (0.79, 1.22) |
| ND | 400 once daily | 1.15 (0.97, 1.36) | 1.09 (0.94, 1.26) | 0.99 (0.80, 1.23) |
| Midazolam | 2.5 single dose | 90 single dose | ND | 30 | 1.07 (1.00, 1.14) | 0.99 (0.95, 1.04) | NA |
0.95 (0.87, 1.04) | 0.89 (0.84, 0.95) | NA |
| Raltegravir | 400 twice daily | 90 once daily | ND | 28 | 0.82 (0.66, 1.02) | 0.85 (0.70, 1.02) | 1.15 (0.90, 1.46) |
| ND | 400 single dose | 19 | 0.57 (0.44, 0.75) | 0.73 (0.59, 0.91) | 0.95 (0.81, 1.12) |
| Simeprevir | 150 once daily | 30 once daily | ND | 22 | 2.61 (2.39, 2.86) | 2.69 (2.44, 2.96) | NA |
| Tacrolimus | 5 single dose | ND | 400 single dose | 16 | 0.73 (0.59, 0.90) | 1.09 (0.84, 1.40) | NA |
| Tenofovir DF | 300 once daily
| 90 once daily | 400 once daily | 15 | 1.79 (1.56, 2.04) | 1.98 (1.77, 2.23) | 2.63 (2.32, 2.97) |
No effect on the pharmacokinetic parameters of the following coadministered drugs was observed with ledipasvir or sofosbuvir: abacavir, cyclosporine, darunavir/ritonavir, dolutegravir, efavirenz, emtricitabine, lamivudine, methadone, or rilpivirine.