Sitagliptin

1 INDICATIONS AND USAGE JANUVIA ® is indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. JANUVIA is a dipeptidyl peptidase-4 (DPP-4) inhibitor indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. ( 1 ) Limitations of Use: JANUVIA should not be used in patients with type 1 diabetes ( 1 ) JANUVIA has not been studied in patients with a history of pancreatitis. ( 1 , 5.1 ) Limitations of Use JANUVIA should not be used in patients with type 1 diabetes. JANUVIA has not been studied in patients with a history of pancreatitis. It is unknown whether patients with a history of pancreatitis are at increased risk for the development of pancreatitis while using JANUVIA. [See Warnings and Precautions (5.1) .]

2 DOSAGE AND ADMINISTRATION The recommended dose of JANUVIA is 100 mg once daily. JANUVIA can be taken with or without food. ( 2.1 ) Dosage adjustment is recommended for patients with eGFR less than 45 mL/min/1.73 m 2 . ( 2.2 ) Dosage Adjustment in Patients with Renal Impairment ( 2.2 ) eGFR greater than or equal to 30 mL/min/1.73 m 2 to less than 45 mL/min/1.73 m 2 eGFR less than 30 mL/min/1.73 m 2 (including patients with end stage renal disease [ESRD] on dialysis) 50 mg once daily 25 mg once daily 2.1 Recommended Dosing The recommended dose of JANUVIA is 100 mg once daily. JANUVIA can be taken with or without food. 2.2 Recommendations for Use in Renal Impairment Assess renal function prior to initiation of JANUVIA and periodically thereafter. For patients with an estimated glomerular filtration rate [eGFR] greater than or equal to 45 mL/min/1.73 m 2 to less than 90 mL/min/1.73 m 2 , no dosage adjustment for JANUVIA is required. For patients with moderate renal impairment (eGFR greater than or equal to 30 mL/min/1.73 m 2 to less than 45 mL/min/1.73 m 2 ), the dose of JANUVIA is 50 mg once daily. For patients with severe renal impairment (eGFR less than 30 mL/min/1.73 m 2 ) or with end-stage renal disease (ESRD) requiring hemodialysis or peritoneal dialysis, the dose of JANUVIA is 25 mg once daily. JANUVIA may be administered without regard to the timing of dialysis.

6 ADVERSE REACTIONS The following adverse reactions are also discussed elsewhere in the labeling: Pancreatitis [see Warnings and Precautions (5.1) ] Heart Failure [see Warnings and Precautions (5.2) ] Acute Renal Failure [see Warnings and Precautions (5.3) ] Hypoglycemia with Concomitant Use with Insulin or Insulin Secretagogues [see Warnings and Precautions (5.4) ] Hypersensitivity Reactions [see Warnings and Precautions (5.5) ] Severe and Disabling Arthralgia [see Warnings and Precautions (5.6) ] Bullous Pemphigoid [see Warnings and Precautions (5.7) ] Adverse reactions reported in ≥5% of patients treated with JANUVIA and more commonly than in patients treated with placebo are: upper respiratory tract infection, nasopharyngitis and headache. In the add-on to sulfonylurea and add-on to insulin studies, hypoglycemia was also more commonly reported in patients treated with JANUVIA compared to placebo. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Merck Sharp & Dohme LLC at 1-877-888-4231 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. In controlled clinical studies as both monotherapy and combination therapy with metformin, pioglitazone, or rosiglitazone and metformin, the overall incidence of adverse reactions, hypoglycemia, and discontinuation of therapy due to clinical adverse reactions with JANUVIA were similar to placebo. In combination with glimepiride, with or without metformin, the overall incidence of clinical adverse reactions with JANUVIA was higher than with placebo, in part related to a higher incidence of hypoglycemia (see Table 3); the incidence of discontinuation due to clinical adverse reactions was similar to placebo. Two placebo-controlled monotherapy studies, one of 18- and one of 24-week duration, included patients treated with JANUVIA 100 mg daily, JANUVIA 200 mg daily, and placebo. Five placebo-controlled add-on combination therapy studies were also conducted: one with metformin; one with pioglitazone; one with metformin and rosiglitazone; one with glimepiride (with or without metformin); and one with insulin (with or without metformin). In these trials, patients with inadequate glycemic control on a stable dose of the background therapy were randomized to add-on therapy with JANUVIA 100 mg daily or placebo. The adverse reactions, excluding hypoglycemia, reported regardless of investigator assessment of causality in ≥5% of patients treated with JANUVIA 100 mg daily and more commonly than in patients treated with placebo, are shown in Table 1 for the clinical trials of at least 18 weeks duration. Incidences of hypoglycemia are shown in Table 3. Table 1: Placebo-Controlled Clinical Studies of JANUVIA Monotherapy or Add-on Combination Therapy with Pioglitazone, Metformin + Rosiglitazone, or Glimepiride +/- Metformin: Adverse Reactions (Excluding Hypoglycemia) Reported in ≥5% of Patients and More Commonly than in Patients Given Placebo, Regardless of Investigator Assessment of Causality Intent-to-treat population Number of Patients (%) Monotherapy (18 or 24 weeks) JANUVIA 100 mg Placebo N = 443 N = 363 Nasopharyngitis 23 (5.2) 12 (3.3) Combination with Pioglitazone (24 weeks) JANUVIA 100 mg + Pioglitazone Placebo + Pioglitazone N = 175 N = 178 Upper Respiratory Tract Infection 11 (6.3) 6 (3.4) Headache 9 (5.1) 7 (3.9) Combination with Metformin + Rosiglitazone (18 weeks) JANUVIA 100 mg + Metformin + Rosiglitazone Placebo + Metformin + Rosiglitazone N = 181 N = 97 Upper Respiratory Tract Infection 10 (5.5) 5 (5.2) Nasopharyngitis 11 (6.1) 4 (4.1) Combination with Glimepiride (+/- Metformin) (24 weeks) JANUVIA 100 mg + Glimepiride (+/- Metformin) Placebo + Glimepiride (+/- Metformin) N = 222 N = 219 Nasopharyngitis 14 (6.3) 10 (4.6) Headache 13 (5.9) 5 (2.3) In the 24-week study of patients receiving JANUVIA as add-on combination therapy with metformin, there were no adverse reactions reported regardless of investigator assessment of causality in ≥5% of patients and more commonly than in patients given placebo. In the 24-week study of patients receiving JANUVIA as add-on therapy to insulin (with or without metformin), there were no adverse reactions reported regardless of investigator assessment of causality in ≥5% of patients and more commonly than in patients given placebo, except for hypoglycemia (see Table 3). In the study of JANUVIA as add-on combination therapy with metformin and rosiglitazone (Table 1), through Week 54 the adverse reactions reported regardless of investigator assessment of causality in ≥5% of patients treated with JANUVIA and more commonly than in patients treated with placebo were: upper respiratory tract infection (JANUVIA, 15.5%; placebo, 6.2%), nasopharyngitis (11.0%, 9.3%), peripheral edema (8.3%, 5.2%), and headache (5.5%, 4.1%). In a pooled analysis of the two monotherapy studies, the add-on to metformin study, and the add-on to pioglitazone study, the incidence of selected gastrointestinal adverse reactions in patients treated with JANUVIA was as follows: abdominal pain (JANUVIA 100 mg, 2.3%; placebo, 2.1%), nausea (1.4%, 0.6%), and diarrhea (3.0%, 2.3%). In an additional, 24-week, placebo-controlled factorial study of initial therapy with sitagliptin in combination with metformin, the adverse reactions reported (regardless of investigator assessment of causality) in ≥5% of patients are shown in Table 2. Table 2: Initial Therapy with Combination of Sitagliptin and Metformin: Adverse Reactions Reported (Regardless of Investigator Assessment of Causality) in ≥5% of Patients Receiving Combination Therapy (and Greater than in Patients Receiving Metformin alone, Sitagliptin alone, and Placebo) Intent-to-treat population. Number of Patients (%) Placebo Sitagliptin (JANUVIA) 100 mg QD Metformin HCl 500 or 1000 mg bid Data pooled for the patients given the lower and higher doses of metformin. Sitagliptin 50 mg bid + Metformin HCl 500 or 1000 mg bid N = 176 N = 179 N = 364 N = 372 Upper Respiratory Infection 9 (5.1) 8 (4.5) 19 (5.2) 23 (6.2) Headache 5 (2.8) 2 (1.1) 14 (3.8) 22 (5.9) In a 24-week study of initial therapy with JANUVIA in combination with pioglitazone, there were no adverse reactions reported (regardless of investigator assessment of causality) in ≥5% of patients and more commonly than in patients given pioglitazone alone. No clinically meaningful changes in vital signs or in ECG (including in QTc interval) were observed in patients treated with JANUVIA. In a pooled analysis of 19 double-blind clinical trials that included data from 10,246 patients randomized to receive sitagliptin 100 mg/day (N=5429) or corresponding (active or placebo) control (N=4817), the incidence of acute pancreatitis was 0.1 per 100 patient-years in each group (4 patients with an event in 4708 patient-years for sitagliptin and 4 patients with an event in 3942 patient-years for control). Hypoglycemia In the above studies (N=9), adverse reactions of hypoglycemia were based on all reports of symptomatic hypoglycemia. A concurrent blood glucose measurement was not required although most (74%) reports of hypoglycemia were accompanied by a blood glucose measurement ≤70 mg/dL. When JANUVIA was coadministered with a sulfonylurea or with insulin, the percentage of patients with at least one adverse reaction of hypoglycemia was higher than in the corresponding placebo group (Table 3). Table 3: Incidence and Rate of Hypoglycemia Adverse reactions of hypoglycemia were based on all reports of symptomatic hypoglycemia; a concurrent glucose measurement was not required; intent-to-treat population. in Placebo-Controlled Clinical Studies when JANUVIA was used as Add-On Therapy to Glimepiride (with or without Metformin) or Insulin (with or without Metformin), Regardless of Investigator Assessment of Causality Add-On to Glimepiride (+/- Metformin) (24 weeks) JANUVIA 100 mg + Glimepiride (+/- Metformin) Placebo + Glimepiride (+/- Metformin) N = 222 N = 219 Overall (%) 27 (12.2) 4 (1.8) Rate (episodes/patient-year) Based on total number of events (i.e., a single patient may have had multiple events). 0.59 0.24 Severe (%) Severe events of hypoglycemia were defined as those events requiring medical assistance or exhibiting depressed level/loss of consciousness or seizure. 0 (0.0) 0 (0.0) Add-On to Insulin (+/- Metformin) (24 weeks) JANUVIA 100 mg + Insulin (+/- Metformin) Placebo + Insulin (+/- Metformin) N = 322 N = 319 Overall (%) 50 (15.5) 25 (7.8) Rate (episodes/patient-year) 1.06 0.51 Severe (%) 2 (0.6) 1 (0.3) In a pooled analysis of the two monotherapy studies, the add-on to metformin study, and the add-on to pioglitazone study, the overall incidence of adverse reactions of hypoglycemia was 1.2% in patients treated with JANUVIA 100 mg and 0.9% in patients treated with placebo. In the study of JANUVIA as add-on combination therapy with metformin and rosiglitazone, the overall incidence of hypoglycemia was 2.2% in patients given add-on JANUVIA and 0.0% in patients given add-on placebo through Week 18. Through Week 54, the overall incidence of hypoglycemia was 3.9% in patients given add-on JANUVIA and 1.0% in patients given add-on placebo. In the 24-week, placebo-controlled factorial study of initial therapy with JANUVIA in combination with metformin, the incidence of hypoglycemia was 0.6% in patients given placebo, 0.6% in patients given JANUVIA alone, 0.8% in patients given metformin alone, and 1.6% in patients given JANUVIA in combination with metformin. In the study of JANUVIA as initial therapy with pioglitazone, one patient taking JANUVIA experienced a severe episode of hypoglycemia. There were no severe hypoglycemia episodes reported in other studies except in the study involving coadministration with insulin. In an additional, 30-week placebo-controlled, study of patients with type 2 diabetes inadequately controlled with metformin comparing the maintenance of sitagliptin 100 mg versus withdrawal of sitagliptin when initiating basal insulin therapy, the event rate and incidence of documented symptomatic hypoglycemia (blood glucose measurement ≤70 mg/dL) did not differ between the sitagliptin and placebo groups. Laboratory Tests Across clinical studies, the incidence of laboratory adverse reactions was similar in patients treated with JANUVIA 100 mg compared to patients treated with placebo. A small increase in white blood cell count (WBC) was observed due to an increase in neutrophils. This increase in WBC (of approximately 200 cells/microL vs placebo, in four pooled placebo-controlled clinical studies, with a mean baseline WBC count of approximately 6600 cells/microL) is not considered to be clinically relevant. In a 12-week study of 91 patients with chronic renal insufficiency, 37 patients with moderate renal insufficiency were randomized to JANUVIA 50 mg daily, while 14 patients with the same magnitude of renal impairment were randomized to placebo. Mean (SE) increases in serum creatinine were observed in patients treated with JANUVIA [0.12 mg/dL (0.04)] and in patients treated with placebo [0.07 mg/dL (0.07)]. The clinical significance of this added increase in serum creatinine relative to placebo is not known. 6.2 Postmarketing Experience Additional adverse reactions have been identified during postapproval use of JANUVIA as monotherapy and/or in combination with other antihyperglycemic agents. Because these reactions are reported voluntarily from a population of uncertain size, it is generally not possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Hypersensitivity reactions including anaphylaxis, angioedema, rash, urticaria, cutaneous vasculitis, and exfoliative skin conditions including Stevens-Johnson syndrome; hepatic enzyme elevations; acute pancreatitis, including fatal and non-fatal hemorrhagic and necrotizing pancreatitis [see Indications and Usage (1) ] ; worsening renal function, including acute renal failure (sometimes requiring dialysis), and tubulointerstitial nephritis; severe and disabling arthralgia ; bullous pemphigoid ; constipation; vomiting; headache; myalgia; pain in extremity; back pain; pruritus; mouth ulceration; stomatitis; rhabdomyolysis.

12.3 Pharmacokinetics The pharmacokinetics of sitagliptin have been extensively characterized in healthy subjects and patients with type 2 diabetes mellitus. Following a single oral 100-mg dose to healthy volunteers, mean plasma AUC of sitagliptin was 8.52 μM•hr, C max was 950 nM, and apparent terminal half-life (t 1/2 ) was 12.4 hours. Plasma AUC of sitagliptin increased in a dose-proportional manner and 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 After oral administration of a 100 mg dose to healthy subjects, sitagliptin was rapidly absorbed with peak plasma concentrations (median T max ) occurring 1 to 4 hours postdose. The absolute bioavailability of sitagliptin is approximately 87%. Effect of Food Coadministration of a high-fat meal with sitagliptin had no effect on the pharmacokinetics of sitagliptin. Distribution The mean volume of distribution at steady state following a single 100-mg intravenous dose of sitagliptin to healthy subjects is approximately 198 liters. The fraction of sitagliptin reversibly bound to plasma proteins is low (38%). Elimination Approximately 79% of sitagliptin is excreted unchanged in the urine with metabolism being a minor pathway of elimination. The apparent terminal t 1/2 following a 100 mg oral dose of sitagliptin was approximately 12.4 hours and renal clearance was approximately 350 mL/min. Metabolism Following a [ 14 C]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 Following administration of an oral [ 14 C]sitagliptin dose to healthy subjects, approximately 100% of the administered radioactivity was eliminated in feces (13%) or urine (87%) within one week of dosing. 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 (P-gp), which may also be involved in mediating the renal elimination of sitagliptin. However, cyclosporine, a P-gp inhibitor, did not reduce the renal clearance of sitagliptin. Specific Populations Patients with Renal Impairment 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 m 2 , 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 In patients with moderate hepatic impairment (Child-Pugh score 7 to 9), mean AUC and C max 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. There is no clinical experience in patients with severe hepatic impairment (Child-Pugh score >9). Effects of Age, Body Mass Index (BMI), Gender, and Race 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 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-gp substrate, but does not inhibit P-gp 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 Effects of Sitagliptin on Other Drugs In clinical studies, sitagliptin did not meaningfully alter the pharmacokinetics of metformin, glyburide, simvastatin, rosiglitazone, digoxin, warfarin, or an oral contraceptive (ethinyl estradiol and norethindrone) (Table 4), providing in vivo evidence of a low propensity for causing drug interactions with substrates of CYP3A4, CYP2C8, CYP2C9, P-gp, and organic cationic transporter (OCT). Table 4: Effect of Sitagliptin on Systemic Exposure of Coadministered Drugs Coadministered Drug Dose of Coadministered Drug All doses administered as single dose unless otherwise specified. Dose of Sitagliptin Geometric Mean Ratio (ratio with/without sitagliptin) No Effect = 1.00 AUC AUC is reported as AUC 0-∞ unless otherwise specified. C max Digoxin 0.25 mg Multiple dose. once daily for 10 days 100 mg once daily for 10 days Digoxin 1.11 AUC 0-24hr . 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 AUC 0-last . 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 HCl 1000 mg twice daily for 14 days 50 mg twice daily for 7 days Metformin 1.02 AUC 0-12hr . 0.97 Effects of Other Drugs on Sitagliptin Clinical data described below suggest that sitagliptin is not susceptible to clinically meaningful interactions by coadministered medications (Table 5). Table 5: Effect of Coadministered Drugs on Systemic Exposure of Sitagliptin Coadministered Drug Dose of Coadministered Drug All doses administered as single dose unless otherwise specified. Dose of Sitagliptin Geometric Mean Ratio (ratio with/without coadministered drug) No Effect = 1.00 AUC AUC is reported as AUC 0-∞ unless otherwise specified. C max Cyclosporine 600 mg once daily 100 mg once daily Sitagliptin 1.29 1.68 Metformin HCl 1000 mg Multiple dose. twice daily for 14 days 50 mg twice daily for 7 days Sitagliptin 1.02 AUC 0-12hr . 1.05