CLINICAL PHARMACOLOGY
Mechanism Of Action
ODEFSEY is a fixed dose combination of antiretroviral drugs emtricitabine, rilpivirine, and tenofovir alafenamide [see Microbiology].
Pharmacodynamics
Cardiac Electrophysiology
When higher than recommended RPV doses of 75 mg (3 times the recommended dosage in ODEFSEY) once daily and 300 mg (12 times the recommended dosage in ODEFSEY) once daily were studied in healthy adults, the maximum mean time-matched (95% upper confidence bound) differences in QTcF interval from placebo after baseline correction were 10.7 (15.3) and 23.3 (28.4) milliseconds, respectively. Steady-state administration of RPV 75 mg once daily and 300 mg once daily resulted in a mean steady-state Cmax approximately 2.6 times and 6.7 times, respectively, higher than the mean Cmax observed with the recommended 25 mg once daily dose of RPV [see WARNINGS AND PRECAUTIONS].
The effect of RPV at the recommended dose of 25 mg once daily on the QTcF interval was evaluated in a randomized, placebo-, and active-(moxifloxacin 400 mg once daily) controlled crossover study in 60 healthy adults, with 13 measurements over 24 hours at steady state. The maximum mean time-matched (95% upper confidence bound)
differences in QTcF interval from placebo after baseline correction was 2 (5) milliseconds (i.e., below the threshold of clinical concern).
In a thorough QT/QTc study in 48 healthy subjects, TAF at the recommended dose and at a dose approximately 5 times the recommended dose, did not affect the QT/QTc interval and did not prolong the PR interval.
The effect of FTC on the QT interval is not known.
Pharmacokinetics
Absorption, Distribution, Metabolism, And Excretion
The pharmacokinetic properties of the components of ODEFSEY are provided in Table
4. The multiple dose pharmacokinetic parameters of FTC, RPV and TAF and its metabolite tenofovir are provided in Table 5.
Table 4: Pharmacokinetic Properties of the Components of ODEFSEY
|
Rilpivirine |
Emtricitabine |
Tenofovir Alafenamide |
Absorption |
|
|
|
Tmax (h) |
4 |
3 |
1 |
Effect of moderate fat meal (relative to fasting)a |
AUC Ratio = 1.13 (1.03, 1.23) |
AUC Ratio = 0.91 (0.89, 0.93) |
AUC Ratio = 1.45 (1.33, 1.58) |
Effect of high fat meal (relative to fasting)a |
AUC Ratio = 1.72 (1.49, 1.99) |
AUC Ratio = 0.88 (0.85, 0.90) |
AUC Ratio = 1.53 (1.39, 1.69) |
Distribution |
|
|
|
% Bound to human plasma proteins |
~99 |
<4 |
~80 |
Source of protein binding data |
In vitro |
In vitro |
Ex vivo |
Blood-to-plasma ratio |
0.7 |
0.6 |
1.0 |
Metabolism |
|
|
|
Metabolism |
CYP3A |
Not significantly metabolized |
Cathepsin Ab (PBMCs) CES1 (hepatocytes) CYP3A (minimal) |
Elimination |
|
|
|
Major route of elimination |
Metabolism |
Glomerular filtration and active tubular secretion |
Metabolism (>80% of oral dose) |
t1/2 (h)c |
50 |
10 |
0.51 |
% Of dose excreted in urined |
6 |
70 |
<1 |
% Of dose excreted in fecesd |
85 |
13.7 |
31.7 |
PBMCs = peripheral blood mononuclear cells; CES1 = carboxylesterase 1.
a. Values refer to geometric mean ratio [fed/ fasted] in PK parameters and (90% confidence interval). Highcalorie/ high-fat meal = ~800 kcal, 50% fat. Moderate-fat meal = ~600 kcal, 27% fat.
b. In vivo, TAF is hydrolyzed within cells to form tenofovir (major metabolite), which is phosphorylated to the active metabolite, tenofovir diphosphate. In vitro studies have shown that TAF is metabolized to tenofovir by cathepsin A in PBMCs and macrophages; and by CES1 in hepatocytes. Upon coadministration with the moderate CYP3A inducer probe efavirenz, TAF exposure was unaffected.
c. t1/2 values refer to median terminal plasma half-life. Note that the pharmacologically active metabolite, tenofovir diphosphate, has a half-life of 150-180 hours within PBMCs.
d. Dosing in mass balance studies: FTC (single dose administration of [14C] emtricitabine after multiple dosing of emtricitabine for ten days); TAF (single dose administration of [14C] tenofovir alafenamide). |
Table 5: Multiple Dose Pharmacokinetic Parameters of Emtricitabine, Rilpivirine, Tenofovir Alafenamide and its Metabolite Tenofovir Following Oral Administration with a Meal in HIV-Infected Adults
Parameter Mean (CV%) |
Emtricitabinea |
Rilpivirineb |
Tenofovir Alafenamidec |
Tenofovird |
Cmax (microgram per mL) |
2.1 (20.2) |
NA |
0.16 (51.1) |
0.02 (26.1) |
AUCtau (microgram•hour per mL) |
11.7 (16.6) |
2.2 (38.1) |
0.21 (71.8) |
0.29 (27.4) |
Ctrough (microgram per mL) |
0.10 (46.7) |
0.08 (44.3) |
NA |
0.01 (28.5) |
CV = Coefficient of Variation; NA = Not Applicable
a. From Intensive PK analysis in a phase 2 trial in HIV infected adults treated with FTC+TAF with EVG+COBI (n=19).
b. From Population PK analysis in a trial of treatment-naïve adults with HIV-1 infection treated with RPV (n=679).
c. From Population PK analysis in two trials of treatment-naïve adults with HIV-1 infection treated within EVG+COBI+FTC+TAF (n=539).
d.From Population PK analysis in two trials of treatment-naïve adults with HIV-1 infection treated with EVG+COBI+FTC+TAF (n=841). |
Specific Populations
Patients With Renal Impairment
Rilpivirine
Population pharmacokinetic analysis indicated that RPV exposure was similar in HIV-1 infected subjects with eGFR 60 to 89 mL per minute by Cockcroft-Gault method relative to HIV-1 infected subjects with normal renal function. There is limited or no information regarding the pharmacokinetics of RPV in patients with moderate or severe renal impairment or in patients with end-stage renal disease [see Use In Specific Populations].
Tenofovir Alafenamide
The pharmacokinetics of FTC+TAF with EVG+COBI in HIV-1 infected subjects with renal impairment (eGFR 30 to 69 mL per minute by Cockcroft-Gault method) were evaluated within a subset of virologicallysuppressed
subjects in an open-label trial (Table 6).
Table 6: Pharmacokinetics of the FTC, TAF, and a Metabolite of TAF (Tenofovir) in HIV-Infected Adults with Renal Impairment as Compared to Subjects with Normal Renal Function
Creatinine Clearance |
AUCtau (microgram-hour per mL) Mean (CV%) |
≥90 mL per minute (N=18)a |
60–89 mL per minute (N=11)b |
30–59 mL per minute (N=18) |
Emtricitabine |
11.4 (11.9) |
17.6 (18.2) |
23.0 (23.6) |
Tenofovir Alafenamide* |
0.23 (47.2) |
0.24 (45.6) |
0.26 (58.8) |
Tenofovir |
0.32 (14.9) |
0.46 (31.5) |
0.61 (28.4) |
*AUClast
a.From a phase 2 trial in HIV-infected adults with normal renal function treated with FTC+TAF with
EVG+COBI.
b.These subjects had an eGFR ranging from 60 to 69 mL per minute. |
Patients With Hepatic Impairment
Emtricitabine
The pharmacokinetics of FTC have not been studied in subjects with hepatic impairment; however, FTC is not significantly metabolized by liver enzymes, so the impact of hepatic impairment should be limited.
Rilpivirine
In a study comparing 8 subjects with mild hepatic impairment (Child-Pugh score A) to 8 matched controls and 8 subjects with moderate hepatic impairment (Child-Pugh score B) to 8 matched controls, the multiple-dose exposure of RPV was 47% higher in subjects with mild hepatic impairment and 5% higher in subjects with moderate hepatic impairment [see Use In Specific Populations].
Tenofovir Alafenamide
Clinically relevant changes in the pharmacokinetics of tenofovir alafenamide or its metabolite tenofovir were not observed in subjects with mild, moderate, (Child-Pugh A and B) or severe hepatic impairment (Child-Pugh C) [see Use In Specific Populations].
Hepatitis B And/Or Hepatitis C Virus Coinfection
The pharmacokinetics of FTC and TAF have not been fully evaluated in subjects coinfected with hepatitis B and/or C virus. Population pharmacokinetic analysis indicated that hepatitis B and/or C virus coinfection had no clinically relevant effect on the exposure of RPV.
Pediatric Patients
Exposures of TAF in 24 pediatric subjects with HIV-1 infection aged 12 to less than 18 years who received FTC+TAF with EVG+COBI were decreased (23% for TAF AUC) compared to exposures achieved in treatment-naïve adults following administration of FTC+TAF with EVG+COBI. These exposure differences are not
thought to be clinically significant based on exposure-response relationships. FTC exposures were similar in adolescents compared to treatment-naïve adults. The PK of RPV in antiretroviral HIV-1-infected pediatric subjects 12 to less than 18 years of age who received RPV 25 mg once daily were comparable to those in HIV-1 infected adults. As in adults, there was no impact of body weight on RPV PK in pediatric subjects [see Use In Specific Populations].
Geriatric Patients
The pharmacokinetics of FTC and TAF have not been fully evaluated in the elderly (65 years of age and older). Population pharmacokinetics analysis of HIV-infected subjects in Phase 2 and Phase 3 trials of FTC+TAF with EVG+COBI showed that age did not have a clinically relevant effect on exposures of TAF up to 75 years of age.
The pharmacokinetics of RPV have not been fully evaluated in the elderly (65 years of age and older) [see Use In Specific Populations].
Race
Based on population pharmacokinetic analyses, no dosage adjustment is recommended based on race.
Gender
Based on population pharmacokinetic analyses, no dosage adjustment is recommended based on gender.
Drug Interaction Studies
Rilpivirine
RPV is primarily metabolized by CYP3A, and drugs that induce or inhibit CYP3A may thus affect the clearance of RPV.
RPV at a dose of 25 mg once daily is not likely to have a clinically relevant effect on the exposure of medicinal products metabolized by CYP enzymes.
TAF is not an inhibitor of CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, or UGT1A1. TAF is a weak inhibitor of CYP3A in vitro. TAF is not an inhibitor or inducer of CYP3A in vivo.
The drug interaction studies described in Tables 7-10 were conducted with ODEFSEY (FTC/RPV/TAF) or the components of ODEFSEY (FTC, RPV, or TAF) administered individually.
The effects of coadministered drugs on the exposures of RPV and TAF are shown in Tables 7 and 8, respectively. The effects of RPV and TAF on the exposure of coadministered drugs are shown in Tables 9 and 10, respectively. For information regarding clinical recommendations, see DRUG INTERACTIONS.
Table 7: Changes in Pharmacokinetic Parameters for RPV in the Presence of Coadministered Drugs in Healthy Subjects
Coadministered Drug |
Dose/Schedule |
N |
Mean Ratio of RPV Pharmacokinetic Parameters With/Without Coadministered Drug
(90% CI);No Effect = 1.00 |
Coadministered Drug (mg) |
RPV (mg) |
Cmax |
AUC |
Cmin |
Acetaminophen |
500 single dose |
150 once dailya |
16 |
1.09 (1.01, 1.18) |
1.16 (1.10, 1.22) |
1.26 (1.16, 1.38) |
Atorvastatin |
40 once daily |
150 once dailya |
16 |
0.91 (0.79, 1.06) |
0.90 (0.81, 0.99) |
0.90 (0.84, 0.96) |
Chlorzoxazone |
500 single dose taken 2 hours after RPV |
150 once dailya |
16 |
1.17 (1.08, 1.27) |
1.25 (1.16, 1.35) |
1.18 (1.09, 1.28) |
Ethinylestradiol/ Norethindrone |
0.035 once daily /1 mgonce daily |
25 once daily |
15 |
↔b |
↔b |
↔b |
Famotidine |
40 single dose taken 12 hours before RPV |
150 single dosea |
24 |
0.99 (0.84, 1.16) |
0.91 (0.78, 1.07) |
NA |
Famotidine |
40 single dose taken 2 hours before RPV |
150 singledosea |
23 |
0.15 (0.12, 0.19) |
0.24 (0.20, 0.28) |
NA |
Famotidine |
40 single dose taken 4 hours after RPV |
150 singledosea |
24 |
1.21 (1.06, 1.39) |
1.13 (1.01, 1.27) |
NA |
Ketoconazole |
400 once daily |
150 once dailya |
15 |
1.30 (1.13, 1.48) |
1.49 (1.31, 1.70) |
1.76 (1.57, 1.97) |
Methadone |
60-100 once daily, individualized dose |
25 once daily |
12 |
↔b |
↔b |
↔b |
Ledipasvir/ Sofosbuvirc |
90/400 once daily |
25 once daily |
42 |
0.97 (0.92, 1.02) |
0.95 (0.91, 0.98) |
0.93 (0.89, 0.97) |
Omeprazole |
20 once daily |
25 singledose |
15 |
0.30 (0.24, 0.38) |
0.35 (0.28, 0.44) |
NA |
Rifabutin |
300 once daily |
25 once daily |
18 |
0.69 (0.62, 0.76) |
0.58 (0.52, 0.65) |
0.52 (0.46, 0.59) |
Rifampin |
600 once daily |
150 once dailya |
16 |
0.31 (0.27, 0.36) |
0.20 (0.18, 0.23) |
0.11 (0.10, 0.13) |
Simeprevir |
25 once daily |
150 once daily |
23 |
1.04 (0.95, 1.30) |
1.12 (1.05, 1.19) |
1.25 (1.16, 1.35) |
Sildenafil |
50 single dose |
75 once dailya |
16 |
0.92 (0.85, 0.99) |
0.98 (0.92, 1.05) |
1.04 (0.98, 1.09) |
Sofosbuvir/velpatasvir |
400/100 once daily |
10 once dailyd |
24 |
0.93 (0.88,0.98) |
0.95 (0.90, 1.00) |
0.96 (0.90,1.03) |
CI=Confidence Interval; N=maximum number of subjects with data; NA=Not Available; ↔=no change
a. 25 mg, 75 mg, and 150 mg of RPV is 1, 3, and 6 times the recommended dose of RPV in ODEFSEY, respectively.
b. Comparison based on historic controls.
c. Study conducted with ODEFSEY (FTC/RPV/TAF).
d. Study conducted with FTC/RPV/TDF. |
Table 8: Changes in Pharmacokinetic Parameters for TAF in the Presence of the Coadministered Druga in Healthy Subjects
Coadministered Drug |
Dose of Coadministered Drug (mg) |
TAF (mg) |
N |
Mean Ratio of RPV Pharmacokinetic Parameters With/Without Coadministered Drug (90% CI);No Effect = 1.00 |
Cmax |
AUC |
Cmin |
Cobicistatb |
150 once daily |
8 once daily |
12 |
2.83
(2.20, 3.65) |
2.65
(2.29, 3.07) |
NC |
Ledipasvir/ Sofosbuvirc |
90/400 once daily |
25 once daily |
42 |
1.03
(0.94, 1.14) |
1.32
(1.25, 1.40) |
NC |
CI=Confidence Interval; N=maximum number of subjects with data; NC=Not Calculated
a. All interaction studies conducted in healthy volunteers.
b. Increases TAF exposure via inhibition of intestinal P-glycoprotein.
c. Study conducted with ODEFSEY (FTC/RPV/TAF). |
Table 9: Changes in Pharmacokinetic Parameters for Coadministered Drugs in the Presence of RPV in Healthy Subjects
Coadministered Drug |
Dose/Schedule |
N |
Mean Ratio of Coadministered Drug Pharmacokinetic Parameters With/Without RPV (90% CI); No Effect = 1.00 |
Coadministered Drug (mg) |
RPV (mg) |
Cmax |
AUC |
Cmin |
Acetaminophen |
500 single dose |
150 once dailya |
16 |
0.97 (0.86, 1.10) |
0.92 (0.85, 0.99) |
NA |
Atorvastatin |
|
|
|
1.35 (1.08, 1.68) |
1.04 (0.97, 1.12) |
0.85 (0.69, 1.03) |
2-hydroxy atorvastatin |
40 once daily |
150 once dailya |
16 |
1.58 (1.33, 1.87) |
1.39 (1.29, 1.50) |
1.32 (1.10, 1.58) |
4-hydroxy atorvastatin |
|
|
|
1.28 (1.15, 1.43) |
1.23 (1.13, 1.33) |
NA |
Chlorzoxazone |
500 single dose taken 2 hours after RPV |
150 once dailya |
16 |
0.98 (0.85, 1.13) |
1.03 (0.95, 1.13) |
NA |
Digoxin |
0.5 single dose |
25 once daily |
22 |
1.06 (0.97, 1.17) |
0.98 (0.93, 1.04)b |
NA |
Ethinylestradiol |
0.035 once daily |
25 once daily |
17 |
1.17 (1.06, 1.30) |
1.14 (1.10, 1.19) |
1.09 (1.03, 1.16) |
Norethindrone |
1 mg once daily |
0.94 (0.83, 1.06) |
0.89 (0.84, 0.94) |
0.99 (0.90, 1.08) |
Ketoconazole |
400 once daily |
150 once dailya |
14 |
0.85 (0.80, 0.90) |
0.76 (0.70, 0.82) |
0.34 (0.25, 0.46) |
Ledipasvir |
90 once daily |
25 once dailyc |
41 |
1.01 (0.97, 1.05) |
1.02 (0.97, 1.06) |
1.02 (0.98, 1.07) |
Sofosbuvir |
400 once daily |
25 once dailyc |
41 |
0.96 (0.89, 1.04) |
1.05 (1.01, 1.09) |
NA |
GS-331007e |
1.08 (1.05, 1.11) |
1.08 (1.06, 1.10) |
1.10 (1.07, 1.12) |
R(-) methadone |
60-100 once daily, individualized dose |
25 once daily |
13 |
0.86 (0.78, 0.95) |
0.84 (0.74, 0.95) |
0.78 (0.67, 0.91) |
S(+) methadone |
0.87 (0.78, 0.97) |
0.84 (0.74, 0.96) |
0.79 (0.67, 0.92) |
Metformin |
850 single dose |
25 once daily |
20 |
1.02 (0.95, 1.10) |
0.97 (0.90,1.06)d |
NA |
Rifampin |
600 once daily |
150 once dailya |
16 |
1.02 (0.93, 1.12) |
0.99 (0.92, 1.07) |
NA |
25 desacetyl rifampin |
1.00 (0.87, 1.15) |
0.91 (0.77, 1.07) |
NA |
Simeprevir |
150 once daily |
25 once daily |
21 |
1.10 (0.97, 1.26) |
1.06 (0.94, 1.19) |
0.96 (0.83, 1.11) |
Sildenafil |
50 single dose |
75 once dailya |
16 |
0.93 (0.80, 1.08) |
0.97 (0.87, 1.08) |
NA |
N-desmethyl sildenafil |
0.90 (0.80, 1.02) |
0.92 (0.85, 0.99)b |
NA |
Sofosbuvir |
400 once daily |
25 once dailyf |
24 |
1.09 (0.95, 1.25) |
1.16 (1.10, 1.24) |
NA |
GS-331007e |
0.96 (0.90, 1.01) |
1.04 (1.00, 1.07) |
1.12 (1.07, 1.17) |
Velpatasvir |
100 once daily |
25 once dailyf |
24 |
0.96 (0.85, 1.10) |
0.99 (0.88, 1.11) |
1.02 (0.91, 1.15) |
CI=Confidence Interval; N=maximum number of subjects with data; NA=Not Available
a.25 mg, 75 mg, and 150 mg of RPV is 1, 3, and 6 times the recommended dose of RPV in ODEFSEY,respectively.
b. AUC(0-last).
c. Study conducted with ODEFSEY (FTC/RPV/TAF).
d. N (maximum number of subjects with data for AUC(0-∞)=15)
e. The predominant circulating nucleoside metabolite of sofosbuvir.
f. Study conducted with FTC/RPV/TDF. |
Table 10: Changes in Pharmacokinetic Parameters for Coadministered Drug in the Presence of TAF in Healthy Subjects
Coadministered Drug |
Dose of Coadministered Drug (mg) |
TAF (mg) |
N |
Mean Ratio of Coadministered Drug Pharmacokinetic Parameters (90% CI); No Effect = 1.00 |
Cmax |
AUC |
Cmin |
Midazolama |
2.5 single dose, orally |
25 once daily |
18 |
1.02 (0.92, 1.13) |
1.13 (1.04, 1.23) |
NC |
1 single dose, IV |
0.99 (0.89, 1.11) |
1.08 (1.04, 1.13) |
NC |
Ledipasvirb |
90/400 once daily |
25 once daily |
41 |
1.01 (0.97, 1.05) |
1.02 (0.97, 1.06) |
1.02 (0.98,1.07) |
Sofosbuvirb |
0.96 (0.89, 1.04) |
1.05 (1.01, 1.09) |
NC |
GS-331007b,c |
1.08 (1.05, 1.11) |
1.08 (1.06, 1.10) |
1.10 (1.07, 1.12) |
Norelgestromin |
norgestimate 0.180/0.215/0.250 once daily/ethinyl estradiol 0.025 once daily |
25 once dailyd |
29 |
1.17 (1.07,1.26) |
1.12 (1.07, 1.17) |
1.16 (1.08,1.24) |
Norgestrel |
1.10 (1.02, 1.18) |
1.09 (1.01, 1.18) |
1.11 (1.03,1.20) |
Ethinyl estradiol |
1.22 (1.15, 1.29) |
1.11 (1.07, 1.16) |
1.02 (0.93,1.12) |
CI=Confidence Interval; N=maximum number of subjects with data; NC=Not Calculated
a. A sensitive CYP3A4 substrate.
b. Study conducted with ODEFSEY (FTC/RPV/TAF).
c. The predominant circulating nucleoside metabolite of sofosbuvir.
d. Study conducted with FTC/TAF. |
Microbiology
Mechanism Of Action
Emtricitabine
FTC, a synthetic nucleoside analog of cytidine, is phosphorylated by cellular enzymes to form emtricitabine 5'-triphosphate. Emtricitabine 5'-triphosphate inhibits the activity of the HIV-1 reverse transcriptase (RT) by competing with the natural substrate deoxycytidine 5'-triphosphate and by being incorporated into nascent viral DNA which results in chain termination. Emtricitabine 5′-triphosphate is a weak inhibitor of mammalian DNA polymerases α, β, ε, and mitochondrial DNA polymerase γ.
Rilpivirine
RPV is a diarylpyrimidine non-nucleoside reverse transcriptase inhibitor of HIV-1 and inhibits HIV-1 replication by non-competitive inhibition of HIV-1 RT. RPV does not inhibit the human cellular DNA polymerases α, β, and mitochondrial DNA polymerase γ.
Tenofovir Alafenamide
TAF is a phosphonamidate prodrug of tenofovir (2’deoxyadenosine
monophosphate analog). Plasma exposure to TAF allows for permeation into cells and then TAF is intracellularly converted to tenofovir through hydrolysis by cathepsin A. Tenofovir is subsequently phosphorylated by cellular kinases to the active metabolite tenofovir diphosphate. Tenofovir diphosphate inhibits HIV-1 replication through incorporation into viral DNA by the HIV reverse transcriptase, which results in DNA chain termination.
Tenofovir has activity against human immunodeficiency virus (HIV-1). Cell culture studies have shown that both tenofovir and FTC can be fully phosphorylated when combined in cells. Tenofovir diphosphate is a weak inhibitor of mammalian DNA polymerases that include mitochondrial DNA polymerase γ and there is no evidence of toxicity to mitochondria cell culture.
Antiviral Activity In Cell Culture
Emtricitabine, Rilpivirine, and Tenofovir Alafenamide
The combinations of FTC, RPV, and TAF were not antagonistic with each other in cell culture combination antiviral activity assays. In addition, FTC, RPV, and TAF were not antagonistic with a panel of representatives from the major classes of approved anti-HIV agents (NNRTIs, NRTIs, INSTIs, and PIs).
Emtricitabine
The antiviral activity of FTC against laboratory and clinical isolates of HIV1
was assessed in T lymphoblastoid cell lines, the MAGI-CCR5 cell line, and primary peripheral blood mononuclear cells (PBMCs). The EC50 values for FTC were in the range of 0.0013–0.64 microM. FTC displayed antiviral activity in cell culture against HIV-1 clades A, B, C, D, E, F, and G (EC50 values ranged from 0.007–0.075 microM) and showed strain-specific activity against HIV-2 (EC50 values ranged from 0.007–1.5 microM).
Rilpivirine
RPV exhibited activity against laboratory strains of wild-type HIV-1 in an acutely infected T-cell line with a median EC50 value for HIV-1IIIB of 0.73 nM. RPV demonstrated limited activity in cell culture against HIV-2 with a median EC50 value of 5220 nM (range 2510–10,830 nM). RPV demonstrated antiviral activity against a broad panel of HIV-1 group M (subtype A, B, C, D, F, G, H) primary isolates with EC50 values ranging from 0.07–1.01 nM and was less active against group O primary isolates with EC50 values ranging from 2.88–8.45 nM.
Tenofovir Alafenamide
The antiviral activity of TAF against laboratory and clinical isolates of HIV-1 subtype B was assessed in lymphoblastoid cell lines, PBMCs, primary monocyte/macrophage cells and CD4-T lymphocytes. The EC50 values for TAF ranged from 2.0–14.7 nM.
TAF displayed antiviral activity in cell culture against all HIV-1 groups (M, N, O), including sub-types A, B, C, D, E, F, and G (EC50 values ranged from 0.10–12.0 nM) and strain specific activity against HIV-2 (EC50 values ranged from 0.91–2.63 nM).
Resistance
In Cell Culture
Emtricitabine: HIV-1 isolates with reduced susceptibility to FTC were selected in cell culture. Reduced susceptibility to FTC was associated with M184V or I substitutions in HIV-1 RT.
Rilpivirine: RPV-resistant strains were selected in cell culture starting from wild-type HIV-1 of different origins and subtypes as well as NNRTI-resistant HIV-1. The frequently observed amino acid substitutions that emerged and conferred decreased phenotypic susceptibility to RPV included: L100I, K101E, V106I and A, V108I, E138K and G, Q, R, V179F and I, Y181C and I, V189I, G190E, H221Y, F227C, and M230I and L.
Tenofovir Alafenamide: HIV-1 isolates with reduced susceptibility to TAF were selected in cell culture. HIV-1 isolates selected by TAF expressed a K65R substitution in HIV-1 RT, sometimes in the presence of S68N or L429I substitutions; in addition, a K70E substitution in HIV-1 RT was observed.
In Clinical Trials
In HIV-1-Infected Subjects With No Antiretroviral Treatment History
Emtricitabine and Tenofovir Alafenamide: The resistance profile of ODEFSEY for the treatment of HIV-1 infection is based on studies of FTC+TAF with EVG+COBI in the treatment of HIV-1 infection. In a pooled analysis of antiretroviral-naïve subjects, genotyping was performed on plasma HIV-1 isolates from all subjects with HIV-1 RNA greater than 400 copies per mL at confirmed virologic failure, at Week 48, or at time of early study drug discontinuation. Genotypic resistance developed in 7 of 14 evaluable subjects. The resistance–associated substitutions that emerged were M184V/I (N=7) and K65R (N=1). Three subjects had virus with emergent R, H, or E at the polymorphic Q207 residue in reverse transcriptase.
Rilpivirine: In the Week 96 pooled resistance analysis for adult subjects receiving RPV or efavirenz in combination with FTC/TDF, the emergence of resistance was greater among subjects’ viruses in the RPV+FTC/TDF arm compared to the efavirenz + FTC/TDF arm and was dependent on baseline viral load. In the Week 96 resistance analysis, 14% (77/550) of the subjects in the RPV+FTC/TDF arm and 8% (43/546) of the subjects in the efavirenz + FTC/TDF arm qualified for resistance analysis; 61% (47/77) of the subjects who qualified for resistance analysis (resistance-analysis subjects) in the RPV+FTC/TDF arm had virus with genotypic and/or phenotypic resistance to RPV compared to 42% (18/43) of the resistance-analysis subjects in the efavirenz + FTC/TDF arm who had genotypic and/or phenotypic resistance to efavirenz. Moreover, genotypic and/or phenotypic resistance to emtricitabine or tenofovir emerged in viruses from 57%
(44/77) of the resistance-analysis subjects in the RPV arm compared to 26% (11/43) in the efavirenz arm.
Emerging NNRTI substitutions in the RPV resistance analysis of subjects’ viruses included V90I, K101E/P/T, E138K/A/Q/G, V179I/L, Y181C/I, V189I, H221Y, F227C/L, and M230L, which were associated with an RPV phenotypic fold change range of 2.6–621. The E138K substitution emerged most frequently during RPV treatment, commonly in combination with the M184I substitution. The emtricitabine and lamivudine resistance-associated substitutions M184I or V and NRTI resistance-associated substitutions (K65R/N, A62V, D67N/G, K70E, Y115F, K219E/R) emerged more frequently in the RPV resistance-analysis subjects than in efavirenz resistance-analysis subjects.
NNRTI-and NRTI-resistance substitutions emerged less frequently in the resistance analysis of viruses from subjects with baseline viral loads of less than or equal to 100,000 copies/mL compared to viruses from subjects with baseline viral loads of greater than 100,000 copies/mL: 23% (10/44) compared to 77% (34/44) of NNRTI-resistance substitutions and 20% (9/44) compared to 80% (35/44) of NRTI-resistance substitutions. This difference was also observed for the individual emtricitabine/lamivudine and tenofovir resistance substitutions: 22% (9/41) compared to 78% (32/41) for M184I/V and 0% (0/8) compared to 100% (8/8) for K65R/N. Additionally, NNRTI and/or NRTI-resistance substitutions emerged less frequently in the resistance analysis of the viruses from subjects with baseline CD4+ cell counts greater than or equal to 200 cells/mm3 compared to the viruses from subjects with baseline CD4+ cell counts less than 200 cells/mm3: 32% (14/44) compared to 68% (30/44) of NNRTI-resistance substitutions and 27% (12/44) compared to 73% (32/44) of NRTI-resistance substitutions.
In Virologically-Suppressed Subjects
Emtricitabine and Tenofovir Alafenamide: One subject was identified with emergent resistance to FTC or TAF (M184M/I) out of 4 virologic failure subjects in a clinical study of virologically-suppressed subjects who switched from a regimen containing FTC+TDF to FTC+TAF with EVG+COBI (N=799).
Rilpivirine: Through Week 48, 4 subjects who switched their protease inhibitor-based regimen to FTC/RPV/TDF (4 of 469 subjects, 0.9%) and 1 subject who maintained their regimen (1 of 159 subjects, 0.6%) developed genotypic and/or phenotypic resistance to a study drug. All 4 of the subjects who had resistance emergence on FTC/RPV/TDF had evidence of FTC resistance and 3 of the subjects had evidence of RPV resistance.
ODEFSEY: Through Week 48, in subjects who switched to ODEFSEY from FTC/RPV/TDF or EFV/FTC/TDF (Trials 1216 (N=316) and 1160 (N=438), respectively), of seven subjects who developed virologic failure, three subjects had detectable NNRTI and/or NRTI resistance substititions at virologic failure that were pre-existing in the baseline sample by proviral DNA sequencing; one of these subjects resuppressed while maintaining ODEFSEY.
Cross-Resistance
Emtricitabine: FTC-resistant viruses with the M184V/I substitution were cross-resistant to lamivudine, but retained sensitivity to didanosine, stavudine, tenofovir, and zidovudine.
Viruses harboring substitutions conferring reduced susceptibility to stavudine and zidovudine—thymidine analog substitutions (M41L, D67N, K70R, L210W, T215Y/F, K219Q/E), or didanosine (L74V) remained sensitive to FTC. HIV-1 containing the K103N substitution or other substitutions associated with resistance to NNRTIs was susceptible to FTC.
Rilpivirine: Considering all of the available cell culture and clinical data, any of the following amino acid substitutions, when present at baseline, are likely to decrease the antiviral activity of RPV: K101E, K101P, E138A, E138G, E138K, E138R, E138Q, V179L, Y181C, Y181I, Y181V, Y188L, H221Y, F227C, M230I, M230L, and the combination of L100I+K103N.
Cross-resistance in site-directed mutant virus has been observed among NNRTIs. The single NNRTI substitutions K101P, Y181I, and Y181V conferred 52 times, 15 times, and 12 times decreased susceptibility to RPV, respectively. The combination of E138K and M184I showed 6.7 times reduced susceptibility to RPV compared to 2.8 times for E138K alone. The K103N substitution did not show reduced susceptibility to RPV by itself. However, the combination of K103N and L100I resulted in a 7 times reduced susceptibility to RPV. In another study, the Y188L substitution resulted in a reduced susceptibility to RPV of 9 times for clinical isolates and 6 times for site-directed mutants. Combinations of 2 or 3 NNRTI resistance-associated substitutions gave decreased susceptibility to RPV (fold change range of 3.7–554) in 38% and 66% of mutants, respectively.
Cross-resistance to efavirenz, etravirine, and/or nevirapine is likely after virologic failure and development of RPV resistance.
Tenofovir Alafenamide: Tenofovir resistance substitutions K65R and K70E result in reduced susceptibility to abacavir, didanosine, emtricitabine, lamivudine, and tenofovir.
HIV-1 with multiple thymidine analog substitutions (M41L, D67N, K70R, L210W, T215F/Y, K219Q/E/N/R), or multinucleoside resistant HIV-1 with a T69S double insertion mutation or with a Q151M substitution complex including K65R showed reduced susceptibility to TAF in cell culture.
Animal Toxicology And/Or Pharmacology
Minimal to slight infiltration of mononuclear cells in the posterior uvea was observed in dogs with similar severity after three-and nine-month administration of TAF; reversibility was seen after a three-month recovery period. No eye toxicity was observed in the dog at systemic exposures of 5 (TAF) and 15 (tenofovir) times the exposure seen in humans at the recommended daily TAF dose in ODEFSEY.
Clinical Studies
Clinical Trial Results In HIV-1 Virologically-Suppressed Subjects Who Switched To ODEFSEY
In Trial 1216, the efficacy and safety of switching from emtricitabine/rilpivirine/tenofovir disoproxil fumarate (FTC/RPV/TDF) to ODEFSEY were evaluated in a randomized, double-blind study of virologically-suppressed HIV-1 infected adults. Subjects were suppressed (HIV-1 RNA <50 copies/mL) on their baseline regimen of FTC/RPV/TDF for at least 6 months and have no documented resistance mutations to FTC, TAF, or RPV prior to study entry. Subjects were randomized in a 1:1 ratio to either switch to ODEFSEY (N=316) once daily or stay on FTC/RPV/TDF (N=314) once daily. Subjects had a mean age of 45 years (range: 23−72), 90% were male, 75% were White, and 19% were Black. The mean baseline CD4+ cell count was 709 cells/mm3 (range: 104−2527).
In Trial 1160, the efficacy and safety of switching from efavirenz/emtricitabine/tenofovir disoproxil fumarate (EFV/FTC/TDF) to ODEFSEY were evaluated in a randomized, double-blind study of virologically-suppressed HIV-1 infected adults. Subjects must have been stably suppressed (HIV-1 RNA <50 copies/mL) on their baseline regimen of EFV/FTC/TDF for at least 6 months and have no documented resistance mutations to FTC, TAF, or RPV prior to study entry. Subjects were randomized in a 1:1 ratio to either switch to ODEFSEY (N=438) once daily or stay on EFV/FTC/TDF (N=437) once daily. Subjects had a mean age of 48 years (range: 19−76), 87% were male, 67% were White, and 27% were Black. The mean baseline CD4+ cell count was 700 cells/mm3 (range: 140−1862).
Treatment outcomes of Trials 1216 and 1160 are presented in Table 11.
Table 11: Virologic Outcomes of Trials 1216 and 1160 at Week 48a in Virologically-Suppressed Subjects who Switched to ODEFSEY
|
Study 1216 |
Study 1160 |
ODEFSEY (N=316) |
FTC/RPV/TDF (N=313)b |
ODEFSEY (N=438) |
EFV/FTC/TDF (N=437) |
HIV-1 RNA <50 copies/mL |
94% |
94% |
90% |
92% |
HIV-1 RNA ≥50 copies/mLc |
1% |
0% |
1% |
1% |
No Virologic Data at Week 48 Window |
6% |
6% |
9% |
7% |
Discontinued Study Drug Due to AE or Death and Last Available HIV-1 RNA <50 copies/mL |
2% |
1% |
3% |
1% |
Discontinued Study Drug Due to Other Reasons and Last Available HIV-1 RNA <50 copies/mL d |
4% |
4% |
5% |
5% |
Missing Data During Window but on Study Drug |
<1% |
1% |
1% |
1% |
a. Week 48 window was between Day 295 and 378 (inclusive).
b. One subject who was not on FTC/RPV/TDF prior to screening was excluded from the efficacy analysis.
c. Included subjects who had HIV-1 RNA ≥50 copies/mL in the Week 48 window; subjects who discontinued early due to lack or loss of efficacy; subjects who discontinued for reasons other than
lack or loss of efficacy and at the time of discontinuation had a viral value of ≥50 copies/mL.
d. Includes subjects who discontinued for reasons other than an AE, death, or lack or loss of efficacy; e.g., withdrew consent, loss to follow-up, etc. |
Clinical Trial Results For Subjects With No Antiretroviral Treatment History For Components Of ODEFSEY
The efficacy of RPV, FTC, and TAF in the treatment of HIV-1 infection in adults as initial therapy in those with no antiretroviral treatment history [see INDICATIONS AND USAGE] was established in trials of:
- RPV+FTC/TDF in HIV-1 infected adults as initial therapy in those with no antiretroviral treatment history (n=550). The virologic response rate (i.e., HIV-1 RNA less than 50 copies per mL) was 77% at Week 96. The virologic response rate at 96 weeks was 83% in subjects with baseline HIV-1 RNA less than or equal to 100,000 copies per mL and 71% in subjects with baseline HIV-1 RNA greater than 100,000 copies per mL. Further, the virologic response rate at 96 weeks among subjects with baseline CD4+ cell counts less than 200 and greater than or equal to 200 cells/mm3 were 68% and 82%, respectively.
- FTC+TAF with EVG+COBI in HIV-1 infected adults as initial therapy in those with no antiretroviral treatment history (n=866). The virologic response rate (i.e., HIV-1 RNA less than 50 copies per mL) was 92% at Week 48.
The efficacy of RPV, FTC, and TAF in the treatment of HIV-1 infection in pediatric patients aged 12 to less than 18 years old and greater than 32-35 kg as initial therapy in those with no antiretroviral treatment history and to replace a stable antiretroviral regimen in those who are virologically-suppressed [see INDICATIONS AND USAGE] was established in trials of antiretroviral treatment-naïve HIV-1 infected pediatric subjects 12 to less than 18 years old with:
- RPV in combination with other antiretroviral agents in 36 treatment-naïve HIV-1 infected adolescents weighing at least 32 kg. The majority of subjects (24/36) received RPV in combination with FTC and TDF. Of these 24 subjects, 20 had a baseline HIV-1 RNA less than or equal to 100,000 copies per mL. The virologic response rate in these 20 subjects (i.e., HIV-1 RNA less than 50 copies per mL) was 80% (16/20) at 48 weeks.
- FTC+TAF with EVG+COBI in 23 adolescents weighing at least 35 kg. The virologic response rate (i.e., HIV-1 RNA less than 50 copies per mL) was 91% at 24 weeks.
In the clinical trial of 248 HIV-1 infected adult patients with estimated creatinine clearance greater than 30 mL per minute but less than 70 mL per minute, 95% (235/248) of the combined populations of treatment-naïve (N=6) begun on FTC+TAF with EVG+COBI and those previously virologically-suppressed on other regimens (N=242) and switched to FTC+TAF with EVG +COBI had HIV-RNA levels less than 50 copies per mL at Week 24.