General Introduction
Ertugliflozin
The pharmacokinetics of ertugliflozin are similar in healthy subjects and patients with type 2 diabetes mellitus. The steady state mean plasma AUC and Cmax were 398 ng∙hr/mL and 81.3 ng/mL, respectively, with 5 mg ertugliflozin once daily treatment, and 1,193 ng∙hr/mL and 268 ng/mL, respectively, with 15 mg ertugliflozin once daily treatment. Steady-state is reached after 4 to 6 days of once-daily dosing with ertugliflozin. Ertugliflozin does not exhibit time-dependent pharmacokinetics and accumulates in plasma up to 10-40% following multiple dosing.
Sitagliptin
The pharmacokinetics of sitagliptin have been extensively characterized in healthy subjects and patients with type 2 diabetes mellitus. After oral administration of a 100-mg dose to healthy subjects, sitagliptin was rapidly absorbed, with peak plasma concentrations (median Tmax) occurring 1 to 4 hours postdose. Plasma AUC of sitagliptin increased in a dose proportional manner. Following a single oral 100-mg dose to healthy volunteers, mean plasma AUC of sitagliptin was 8.52 μM∙hr, Cmax was 950 nM, and apparent terminal half-life (t1/2) was 12.4 hours. Plasma AUC of sitagliptin increased approximately 14% following 100-mg doses at steady state compared to the first dose. The intra subject and inter subject coefficients of variation for sitagliptin AUC were small (5.8% and 15.1%). The pharmacokinetics of sitagliptin was generally similar in healthy subjects and in patients with type 2 diabetes mellitus.
Absorption
STEGLUJAN
The effects of a high-fat meal on the pharmacokinetics of ertugliflozin and sitagliptin when administered as STEGLUJAN tablets are comparable to those reported for the individual tablets. Administration of STEGLUJAN with food decreased ertugliflozin Cmax by 29% and had no meaningful effect on ertugliflozin AUCinf, and on sitagliptin AUCinf and Cmax.
Ertugliflozin
Following single-dose oral administration of 5 mg and 15 mg of ertugliflozin, peak plasma concentrations of ertugliflozin occur at 1 hour postdose (median Tmax) under fasted conditions. Plasma Cmax and AUC of ertugliflozin increase in a dose-proportional manner following single doses from 0.5 mg (0.1 times the lowest recommended dose) to 300 mg (20 times the highest recommended dose) and following multiple doses from 1 mg (0.2 times the lowest recommended dose) to 100 mg (6.7 times the highest recommended dose). The absolute oral bioavailability of ertugliflozin following administration of a 15 mg dose is approximately 100%.
Effect of Food
Administration of ertugliflozin with a high-fat and high-calorie meal decreases ertugliflozin Cmax by 29% and prolongs Tmax by 1 hour, but does not alter AUC as compared with the fasted state. The observed effect of food on ertugliflozin pharmacokinetics is not considered clinically relevant, and ertugliflozin may be administered with or without food. In Phase 3 clinical trials, ertugliflozin was administered without regard to meals.
Sitagliptin
The absolute bioavailability of sitagliptin is approximately 87%. Because coadministration of a high fat meal with sitagliptin had no effect on the pharmacokinetics, sitagliptin may be administered with or without food.
Distribution
Ertugliflozin
The mean steady-state volume of distribution of ertugliflozin following an intravenous dose is 85.5 L. Plasma protein binding of ertugliflozin is 93.6% and is independent of ertugliflozin plasma concentrations. Plasma protein binding is not meaningfully altered in patients with renal or hepatic impairment. The blood-to-plasma concentration ratio of ertugliflozin is 0.66.
Sitagliptin
The mean volume of distribution at steady state following a single 100-mg intravenous dose of sitagliptin to healthy subjects is approximately 198 L. The fraction of sitagliptin reversibly bound to plasma proteins is low (38%).
Elimination
Metabolism
Ertugliflozin
Metabolism is the primary clearance mechanism for ertugliflozin. The major metabolic pathway for ertugliflozin is UGT1A9 and UGT2B7-mediated O-glucuronidation to two glucuronides that are pharmacologically inactive at clinically relevant concentrations. CYP-mediated (oxidative) metabolism of ertugliflozin is minimal (12%).
Sitagliptin
Approximately 79% of sitagliptin is excreted unchanged in the urine with metabolism being a minor pathway of elimination.
Following a [14C]sitagliptin oral dose, approximately 16% of the radioactivity was excreted as metabolites of sitagliptin. Six metabolites were detected at trace levels and are not expected to contribute to the plasma DPP-4 inhibitory activity of sitagliptin. In vitro studies indicated that the primary enzyme responsible for the limited metabolism of sitagliptin was CYP3A4, with contribution from CYP2C8.
Excretion
Ertugliflozin
The mean systemic plasma clearance following an intravenous 100 µg dose was 11.2 L/hr. The mean elimination half-life in type 2 diabetic patients with normal renal function was estimated to be 16.6 hours based on the population pharmacokinetic analysis. Following administration of an oral [14C]-ertugliflozin solution to healthy subjects, approximately 40.9% and 50.2% of the drug-related radioactivity was eliminated in feces and urine, respectively. Only 1.5% of the administered dose was excreted as unchanged ertugliflozin in urine and 33.8% as unchanged ertugliflozin in feces, which is likely due to biliary excretion of glucuronide metabolites and subsequent hydrolysis to parent.
Sitagliptin
Following administration of an oral [14C]sitagliptin dose to healthy subjects, approximately 100% of the administered radioactivity was eliminated in feces (13%) or urine (87%) within one week of dosing. The apparent terminal t1/2 following a 100-mg oral dose of sitagliptin was approximately 12.4 hours and renal clearance was approximately 350 mL/min.
Elimination of sitagliptin occurs primarily via renal excretion and involves active tubular secretion. Sitagliptin is a substrate for human organic anion transporter-3 (hOAT-3), which may be involved in the renal elimination of sitagliptin. The clinical relevance of hOAT-3 in sitagliptin transport has not been established. Sitagliptin is also a substrate of p-glycoprotein, which may also be involved in mediating the renal elimination of sitagliptin. However, cyclosporine, a p-glycoprotein inhibitor, did not reduce the renal clearance of sitagliptin.
Specific Populations
Patients with Renal Impairment
STEGLUJAN
Studies characterizing the pharmacokinetics of ertugliflozin and sitagliptin after administration of STEGLUJAN in renally impaired patients have not been performed [see Dosage and Administration (2.1)].
Ertugliflozin
In a clinical pharmacology study in patients with type 2 diabetes mellitus and mild, moderate, or severe renal impairment (as determined by eGFR), following a single-dose administration of 15 mg ertugliflozin, the mean increases in AUC of ertugliflozin were 1.6-, 1.7-, and 1.6-fold, respectively, for mild, moderate and severe renally-impaired patients, compared to subjects with normal renal function. These increases in ertugliflozin AUC are not considered clinically meaningful. The 24-hour urinary glucose excretion declined with increasing severity of renal impairment [see Warnings and Precautions (5.4) and Use in Specific Populations (8.6)]. The plasma protein binding of ertugliflozin was unaffected in patients with renal impairment.
Sitagliptin
An approximately 2-fold increase in the plasma AUC of sitagliptin was observed in patients with moderate renal impairment with eGFR of 30 to less than 45 mL/min/1.73 m2, and an approximately 4-fold increase was observed in patients with severe renal impairment, including patients with ESRD on hemodialysis, as compared to normal healthy control subjects.
Patients with Hepatic Impairment
Ertugliflozin
Moderate hepatic impairment (based on the Child-Pugh classification) did not result in an increase in exposure of ertugliflozin. The AUC of ertugliflozin decreased by approximately 13%, and Cmax decreased by approximately 21% compared to subjects with normal hepatic function. This decrease in ertugliflozin exposure is not considered clinically meaningful. There is no clinical experience in patients with Child-Pugh class C (severe) hepatic impairment. The plasma protein binding of ertugliflozin was unaffected in patients with moderate hepatic impairment [see Use in Specific Populations (8.7)].
Sitagliptin
In patients with moderate hepatic insufficiency (Child Pugh score 7 to 9), mean AUC and Cmax of sitagliptin increased approximately 21% and 13%, respectively, compared to healthy matched controls following administration of a single 100-mg dose of sitagliptin. These differences are not considered to be clinically meaningful. No dosage adjustment for sitagliptin is necessary for patients with mild or moderate hepatic insufficiency.
There is no clinical experience in patients with severe hepatic insufficiency (Child Pugh score >9) [see Use in Specific Populations (8.7)].
Effects of Age, Body Weight/ Body Mass Index (BMI), Gender, and Race
Ertugliflozin
Based on a population pharmacokinetic analysis, age, body weight, gender, and race do not have a clinically meaningful effect on the pharmacokinetics of ertugliflozin.
Sitagliptin
Based on a population pharmacokinetic analysis or a composite analysis of available pharmacokinetic data, BMI, gender, and race do not have a clinically meaningful effect on the pharmacokinetics of sitagliptin. When the effects of age on renal function are taken into account, age alone did not have a clinically meaningful impact on the pharmacokinetics of sitagliptin based on a population pharmacokinetic analysis. Elderly subjects (65 to 80 years) had approximately 19% higher plasma concentrations of sitagliptin compared to younger subjects.
Drug Interaction Studies
STEGLUJAN
Coadministration of single dose of ertugliflozin (15 mg) and sitagliptin (100 mg) did not meaningfully alter the pharmacokinetics of either ertugliflozin or metformin in healthy subjects.
Pharmacokinetic drug interaction studies with STEGLUJAN have not been performed; however, such studies have been conducted with ertugliflozin and sitagliptin, the individual components of STEGLUJAN.
Ertugliflozin
In Vitro Assessment of Drug Interactions
In in vitro studies, ertugliflozin and ertugliflozin glucuronides did not inhibit CYP450 isoenzymes (CYPs) 1A2, 2C9, 2C19, 2C8, 2B6, 2D6, or 3A4, and did not induce CYPs 1A2, 2B6, or 3A4. Ertugliflozin was not a time-dependent inhibitor of CYP3A in vitro. Ertugliflozin did not inhibit UGT1A6, 1A9, or 2B7 in vitro and was a weak inhibitor (IC50 >39 µM) of UGT1A1 and 1A4. Ertugliflozin glucuronides did not inhibit UGT1A1, 1A4, 1A6, 1A9, or 2B7 in vitro. Overall, ertugliflozin is unlikely to affect the pharmacokinetics of drugs eliminated by these enzymes. Ertugliflozin is a substrate of P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) transporters and is not a substrate of organic anion transporters (OAT1, OAT3), organic cation transporters (OCT1, OCT2), or organic anion transporting polypeptides (OATP1B1, OATP1B3). Ertugliflozin or ertugliflozin glucuronides do not meaningfully inhibit P-gp, OCT2, OAT1, or OAT3 transporters, or transporting polypeptides OATP1B1 and OATP1B3, at clinically relevant concentrations. Overall, ertugliflozin is unlikely to affect the pharmacokinetics of concurrently administered medications that are substrates of these transporters.
In Vivo Assessment of Drug Interactions
No dose adjustment of STEGLUJAN is recommended when coadministered with commonly prescribed medicinal products. Ertugliflozin pharmacokinetics were similar with and without coadministration of metformin, glimepiride, sitagliptin, and simvastatin in healthy subjects (see Figure 1). Coadministration of ertugliflozin with multiple doses of 600 mg once daily rifampin (an inducer of UGT and CYP enzymes) resulted in approximately 39% and 15% mean reductions in ertugliflozin AUC and Cmax, respectively, relative to ertugliflozin administered alone. These changes in exposure are not considered clinically relevant. Ertugliflozin had no clinically relevant effect on the pharmacokinetics of metformin, glimepiride, sitagliptin, and simvastatin when coadministered in healthy subjects (see Figure 2). Physiologically-based PK (PBPK) modeling suggests that coadministration of mefenamic acid (UGT inhibitor) may increase the AUC and Cmax of ertugliflozin by 1.51- and 1.19-fold, respectively. These predicted changes in exposure are not considered clinically relevant.
Sitagliptin
In Vitro Assessment of Drug Interactions
Sitagliptin is not an inhibitor of CYP isozymes CYP3A4, 2C8, 2C9, 2D6, 1A2, 2C19 or 2B6, and is not an inducer of CYP3A4. Sitagliptin is a p-glycoprotein substrate, but does not inhibit p-glycoprotein mediated transport of digoxin. Based on these results, sitagliptin is considered unlikely to cause interactions with other drugs that utilize these pathways.
Sitagliptin is not extensively bound to plasma proteins. Therefore, the propensity of sitagliptin to be involved in clinically meaningful drug-drug interactions mediated by plasma protein binding displacement is very low.
In Vivo Assessment of Drug Interactions
Table 4: Effect of Coadministered Drugs on Systemic Exposure of Sitagliptin| Coadministered Drug | Dose of Coadministered Drug
| Dose of Sitagliptin
| Geometric Mean Ratio (ratio with/without coadministered drug) No Effect = 1.00 |
|---|
| | | | AUC
| Cmax
|
|---|
| No dosing adjustments required for the following: |
| Cyclosporine | 600 mg once daily | 100 mg once daily | Sitagliptin | 1.29 | 1.68 |
| Metformin | 1,000 mg twice daily for 14 days | 50 mg twice daily for 7 days | Sitagliptin | 1.02
| 1.05 |
Table 5: Effect of Sitagliptin on Systemic Exposure of Coadministered Drugs| Coadministered Drug | Dose of Coadministered Drug
| Dose of Sitagliptin
| Geometric Mean Ratio (ratio with/without sitagliptin) No Effect = 1.00 |
|---|
| | | | AUC
| Cmax
|
|---|
| No dosing adjustments required for the following: |
| Digoxin | 0.25 mg once daily for 10 days | 100 mg once daily for 10 days | Digoxin | 1.11
| 1.18 |
| Glyburide | 1.25 mg | 200 mg once daily for 6 days | Glyburide | 1.09 | 1.01 |
| Simvastatin | 20 mg | 200 mg once daily for 5 days | Simvastatin | 0.85
| 0.80 |
| Simvastatin Acid | 1.12
| 1.06 |
| Rosiglitazone | 4 mg | 200 mg once daily for 5 days | Rosiglitazone | 0.98 | 0.99 |
| Warfarin | 30 mg single dose on day 5 | 200 mg once daily for 11 days | S(-) Warfarin | 0.95 | 0.89 |
| R(+) Warfarin | 0.99 | 0.89 |
| Ethinyl estradiol and norethindrone | 21 days once daily of 35 µg ethinyl estradiol with norethindrone 0.5 mg × 7 days, 0.75 mg × 7 days, 1.0 mg × 7 days | 200 mg once daily for 21 days | Ethinyl estradiol | 0.99 | 0.97 |
| Norethindrone | 1.03 | 0.98 |
| Metformin | 1,000 mg twice daily for 14 days | 50 mg twice daily for 7 days | Metformin | 1.02
| 0.97 |