Orenitram treprostinil .25 mg Tablet, Extended Release, 100-count — NDC 66302-302-01 (Billing 66302-0302-01)

12 CLINICAL PHARMACOLOGY

12.1Mechanism of Action The major pharmacologic actions of treprostinil are direct vasodilation of pulmonary and systemic arterial vascular beds, inhibition of platelet aggregation, and inhibition of smooth muscle cell proliferation.

12.2Pharmacodynamics In a clinical trial of 240 healthy adult volunteers, single doses of inhaled treprostinil 54 µg (the target clinical dose) and 84 µg (supratherapeutic inhalation dose) prolonged the corrected QTc interval by approximately 10 msec. The QTc effect dissipated rapidly as the concentration of treprostinil decreased. Orenitram has not been evaluated in a thorough QTc study.

12.3Pharmacokinetics In patients with PAH, pharmacokinetics of treprostinil is dose-proportional for systemic exposure (AUC 0-t ) over the dose range from 0.5 to 15 mg BID. Upon repeat administration with a BID regimen, the accumulation in the systemic exposures to treprostinil is minimal and results in a peak-to-trough ratio of approximately 7. However, a TID regimen will reduce the peak-to-trough fluctuations to approximately 2.5 for the same total daily dose.

Absorption The absolute oral bioavailability of Orenitram is approximately 17%. Maximum treprostinil concentrations occur between approximately 4 and 6 hours following Orenitram administration. Time to reach steady-state concentrations for both BID and TID regimens is approximately 1 to 2 days.

The absorption of Orenitram is affected by food. The AUC inf of treprostinil was increased by 49% and the C max was increased by an average of 13% when Orenitram was administered following a high-fat, high-calorie meal compared to fasting conditions in healthy volunteers. The relative bioavailability of treprostinil following oral administration of Orenitram 1 mg is not significantly altered by meal types ranging from 250 to 500 calories in healthy volunteers.

When Orenitram 1 mg was administered with alcohol at 0.5 mg/kg or the equivalent of 3 servings (at the same time, or ± 1 hour relative to alcohol consumption), there was no significant change (10% to 20% increase) in the exposure to treprostinil compared to Orenitram administered alone. Distribution The treprostinil component of Orenitram is highly bound to human plasma proteins, approximately 96% over a treprostinil concentration range of 0.01 to 10 µg/mL. Metabolism and Excretion In a study conducted in healthy volunteers using [ 14 C] treprostinil, treprostinil was extensively metabolized on the side chain of the molecule via oxidation, oxidative cleavage, dehydration, and glucuronic acid conjugation.

Treprostinil is primarily metabolized by CYP2C8 and to a lesser extent by CYP2C9. No new major metabolites are found upon oral administration compared to parenteral administration of treprostinil. Only 1.13% and 0.19% is excreted as unchanged parent drug in the feces and urine, respectively.

Based on in vitro studies, treprostinil does not inhibit or induce major CYP enzymes [see Drug Interactions (7.1) ] . Specific Populations Hepatic Impairment: In subjects with mild (n=8) hepatic impairment, administration of a single 1 mg dose of Orenitram resulted in a mean C max and an AUC 0-inf that were 1.6- and 2.1-fold values seen in healthy subjects, respectively. With moderate impairment (n=8), the corresponding ratios were 4.0- and 4.8-fold, and with severe impairment (n=6), they were 4.8- and 7.6-fold [see Dosage and Administration (2.3) , Contraindications (4) , and Use in Specific Populations (8.6) ].

Renal Impairment: In patients with severe renal impairment requiring dialysis (n=8), administration of a single 1 mg dose of Orenitram pre- and post-dialysis resulted in an AUC 0-inf that was not significantly altered compared to healthy subjects. Drug Interactions Results of drug interaction studies are shown in Figure 1. Only for the strong CYP2C8 inhibitor does the interaction affect dosing [see Dosage and Administration (2.4) ] .

Figure 1: Impact of Co-Administered Drugs on the Sys… [Excerpted — this section continues on DailyMed.]

12.1Mechanism of Action The major pharmacologic actions of treprostinil are direct vasodilation of pulmonary and systemic arterial vascular beds, inhibition of platelet aggregation, and inhibition of smooth muscle cell proliferation.

12.3Pharmacokinetics In patients with PAH, pharmacokinetics of treprostinil is dose-proportional for systemic exposure (AUC 0-t ) over the dose range from 0.5 to 15 mg BID. Upon repeat administration with a BID regimen, the accumulation in the systemic exposures to treprostinil is minimal and results in a peak-to-trough ratio of approximately 7. However, a TID regimen will reduce the peak-to-trough fluctuations to approximately 2.5 for the same total daily dose.

Absorption The absolute oral bioavailability of Orenitram is approximately 17%. Maximum treprostinil concentrations occur between approximately 4 and 6 hours following Orenitram administration. Time to reach steady-state concentrations for both BID and TID regimens is approximately 1 to 2 days.

The absorption of Orenitram is affected by food. The AUC inf of treprostinil was increased by 49% and the C max was increased by an average of 13% when Orenitram was administered following a high-fat, high-calorie meal compared to fasting conditions in healthy volunteers. The relative bioavailability of treprostinil following oral administration of Orenitram 1 mg is not significantly altered by meal types ranging from 250 to 500 calories in healthy volunteers.

When Orenitram 1 mg was administered with alcohol at 0.5 mg/kg or the equivalent of 3 servings (at the same time, or ± 1 hour relative to alcohol consumption), there was no significant change (10% to 20% increase) in the exposure to treprostinil compared to Orenitram administered alone. Distribution The treprostinil component of Orenitram is highly bound to human plasma proteins, approximately 96% over a treprostinil concentration range of 0.01 to 10 µg/mL. Metabolism and Excretion In a study conducted in healthy volunteers using [ 14 C] treprostinil, treprostinil was extensively metabolized on the side chain of the molecule via oxidation, oxidative cleavage, dehydration, and glucuronic acid conjugation.

Treprostinil is primarily metabolized by CYP2C8 and to a lesser extent by CYP2C9. No new major metabolites are found upon oral administration compared to parenteral administration of treprostinil. Only 1.13% and 0.19% is excreted as unchanged parent drug in the feces and urine, respectively.

Based on in vitro studies, treprostinil does not inhibit or induce major CYP enzymes [see Drug Interactions (7.1) ] . Specific Populations Hepatic Impairment: In subjects with mild (n=8) hepatic impairment, administration of a single 1 mg dose of Orenitram resulted in a mean C max and an AUC 0-inf that were 1.6- and 2.1-fold values seen in healthy subjects, respectively. With moderate impairment (n=8), the corresponding ratios were 4.0- and 4.8-fold, and with severe impairment (n=6), they were 4.8- and 7.6-fold [see Dosage and Administration (2.3) , Contraindications (4) , and Use in Specific Populations (8.6) ].

Renal Impairment: In patients with severe renal impairment requiring dialysis (n=8), administration of a single 1 mg dose of Orenitram pre- and post-dialysis resulted in an AUC 0-inf that was not significantly altered compared to healthy subjects. Drug Interactions Results of drug interaction studies are shown in Figure 1. Only for the strong CYP2C8 inhibitor does the interaction affect dosing [see Dosage and Administration (2.4) ] .

Figure 1: Impact of Co-Administered Drugs on the Systemic Exposure of Treprostinil 1 mg Compared to Orenitram Administered Alone Warfarin: A drug interaction study was carried out with Remodulin co-administered with warfarin (25 mg/day) in healthy volunteers. There was no clinically significant effect of either medication on the pharmacokinetics of treprostinil. Additionally, treprostinil did not affect the pharmacokinetics or pharmacodynamics of warfarin.

The pharmacokinetics of R- and S-warfarin and the international normalized ratio (INR) in healthy subjects given a single 25 mg dose of warfarin were unaffected by continuous subcutaneous infusion of treprostinil at an infusion rate of 10 ng/kg… [Excerpted — this section continues on DailyMed.]

12.2Pharmacodynamics In a clinical trial of 240 healthy adult volunteers, single doses of inhaled treprostinil 54 µg (the target clinical dose) and 84 µg (supratherapeutic inhalation dose) prolonged the corrected QTc interval by approximately 10 msec. The QTc effect dissipated rapidly as the concentration of treprostinil decreased. Orenitram has not been evaluated in a thorough QTc study.

14 CLINICAL STUDIES

14.1Clinical Trials in Pulmonary Arterial Hypertension Four multicenter, randomized, double-blind studies were conducted and compared Orenitram to placebo in a total of 349 (Study 1), 350 (Study 2), 310 (Study 3), and 690 (Study 4) patients with PAH. Study 1 (effect seen with no background vasodilator) Study 1 was a 12-week, randomized (2:1 Orenitram to placebo), double-blind, placebo-controlled, international efficacy and safety study of Orenitram in patients with WHO Group 1 PAH not currently receiving PAH therapy.

The primary efficacy endpoint was placebo-corrected change in six-minute walk distance (6MWD) from Baseline to Week 12. Study drug dose was titrated to a maximum of 12 mg BID based on clinical response and study drug tolerability. Study 1 enrolled 349 patients (overall analysis population) who were not receiving any PAH medication.

At the beginning of the study, subjects were dosed with only the 1 mg tablets with 0.5 and 0.25 mg tablets introduced at sequentially later dates during the study. The primary analysis population consisted of the 228 patients who had access to the 0.25 mg tablet at the time of randomization. Patients were administered Orenitram or placebo twice daily, with the doses titrated to effect over the course of the 12-week trial.

Patients were in WHO functional class II (~33%) and class III (~66%) with either idiopathic or heritable PAH (~75%), collagen vascular disease associated PAH (~19%), or PAH associated with HIV (1%) or congenital heart defect (5%) or other conditions (~6%). The patients' mean baseline 6MWD was approximately 330 meters. In the primary analysis population, 17% of patients discontinued Orenitram compared to 14% of patients on placebo.

The primary efficacy endpoint of the trial was the change in 6MWD at 12 weeks for the primary analysis population. Analysis of Study 1 results demonstrated that those patients receiving Orenitram compared to patients receiving placebo improved their median change in 6MWD by approximately 23 meters (p=0.013) as compared to patients receiving placebo as demonstrated in (Figure 2). The within group median change from baseline was +25 meters for Orenitram and -5 meters for placebo at Week 12 (N=228).

Mean dose (±SD) in the Orenitram group was 2.3 ± 1.3, 3.2 ± 1.9, and 3.4 ± 1.9 mg BID at Weeks 4, 8, and 12, respectively, with a maximum dose of 12 mg BID. The distribution of the 6MWD change from baseline at Week 12 was also plotted across the range of observed values (Figure 3). Figure 2: Estimate of Treatment Effect by Visit for the Primary Analysis Population (Study 1) Figure 3: Plot of the Distribution of Peak 6MWD Changes at Week 12 for the Primary Analysis Population (Study 1) The placebo-corrected median treatment effect on 6MWD was estimated within various subpopulations defined by age, gender, disease etiology, and baseline 6MWD (Figure 4).

Figure 4: Placebo Corrected Median Treatment Effect (with 95% CI) on 6MWD Change from Baseline at Week 12 for Various Subgroups in the Primary Analysis Population (Study 1) Figure 2 Figure 3 Figure 4 Studies 2 and 3 (no effect on a background of ERA, PDE-5 inhibitor, or both) Studies 2 (N=350) and 3 (N=310) were 16-week, randomized, double-blind, placebo-controlled, international efficacy and safety studies of Orenitram in patients with WHO Group 1 PAH. The primary efficacy endpoint was placebo-corrected change in 6MWD from Baseline to Week 16.

Patients were in WHO functional class II (~23%) and class III (~77%) with either idiopathic or heritable PAH (~66%), collagen vascular disease associated PAH (~29%), or PAH associated with HIV (1%) or congenital heart defect (4%). The patients' mean baseline 6MWD was approximately 340 meters. Approximately 40% were receiving both an ERA and a PDE-5 inhibitor.

The results did not demonstrate a benefit in exercise testing with median 6MWD at Week 16. Study 4 (effect seen with a single background PAH therapy) The effect of Orenitram on the progr… [Excerpted — this section continues on DailyMed.]

13 NONCLINICAL TOXICOLOGY

13.1Carcinogenesis, Mutagenesis, Impairment of Fertility Treprostinil diolamine did not demonstrate any carcinogenic effects in mouse or rat carcinogenicity studies. Oral administration of treprostinil diolamine to Tg.rasH2 mice at 0, 5, 10, and 20 mg/kg/day in males and 0, 3, 7.5, and 15 mg/kg/day in females daily for 26 weeks did not significantly increase the incidence of tumors. Oral administration of treprostinil diolamine to Sprague Dawley rats at 0, 1, 3, and 10 mg/kg/day daily for 104 weeks did not significantly increase the incidence of tumors.

The exposures obtained at the highest dose levels used in males and females are about 13- and 18-fold, respectively, the human exposure at the dose of 3.5 mg BID on an AUC basis. In vitro genotoxicity studies with high doses of treprostinil did not demonstrate any mutagenic or clastogenic effects. Treprostinil diolamine was tested in vivo in a rat micronucleus assay and did not induce an increased incidence of micronucleated polychromatic erythrocytes.

In rats, treatment with treprostinil diolamine had no effect on reproductive performance or sperm motility at doses up to 10 mg/kg/day. The exposures at this dose level are about 6- (male) to 11- (female) fold the human exposure at the dose of 3.5 mg BID on an AUC basis.