Sitagliptin

1 INDICATIONS AND USAGE ZITUVIMET is a combination of sitagliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor, and metformin hydrochloride (HCl), a biguanide, indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. ( 1 ) Limitations of Use: ZITUVIMET is not recommended in patients with type 1 diabetes mellitus. ( 1 ) ZITUVIMET has not been studied in patients with a history of pancreatitis. ( 1 ) ZITUVIMET is indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. Limitations of Use ZITUVIMET is not recommended in patients with type 1 diabetes mellitus. ZITUVIMET 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 ZITUVIMET. [see Warnings and Precautions ( 5.2 )].

12.1 Mechanism of Action ZITUVIMET ZITUVIMET combines two antihyperglycemic agents with complementary mechanisms of action to improve glycemic control in patients with type 2 diabetes mellitus: sitagliptin, a DPP- 4 inhibitor, and metformin HCl, a member of the biguanide class. Sitagliptin Sitagliptin is a DPP-4 inhibitor, which is believed to exert its actions in patients with type 2 diabetes mellitus by slowing the inactivation of incretin hormones. Concentrations of the active intact hormones are increased by sitagliptin, thereby increasing and prolonging the action of these hormones. Incretin hormones, including glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), are released by the intestine throughout the day, and levels are increased in response to a meal. These hormones are rapidly inactivated by the enzyme DPP-4. The incretins are part of an endogenous system involved in the physiologic regulation of glucose homeostasis. When blood glucose concentrations are normal or elevated, GLP-1 and GIP increase insulin synthesis and release from pancreatic beta cells by intracellular signaling pathways involving cyclic AMP. GLP-1 also lowers glucagon secretion from pancreatic alpha cells, leading to reduced hepatic glucose production. By increasing and prolonging active incretin levels, sitagliptin increases insulin release and decreases glucagon levels in the circulation in a glucose-dependent manner. Sitagliptin demonstrates selectivity for DPP-4 and does not inhibit DPP-8 or DPP-9 activity in vitro at concentrations approximating those from therapeutic doses. Metformin Metformin is an antihyperglycemic agent which improves glucose tolerance in patients with type 2 diabetes mellitus, lowering both basal and postprandial plasma glucose. Metformin decreases hepatic glucose production, decreases intestinal absorption of glucose, and improves insulin sensitivity by increasing peripheral glucose uptake and utilization. With metformin therapy, insulin secretion remains unchanged while fasting insulin levels and day-long plasma insulin response may decrease.

2 DOSAGE AND ADMINISTRATION Take ZITUVIMET orally twice daily with meals. ( 2.1 ) Individualize the dosage of ZITUVIMET on the basis of the patient's current regimen, effectiveness, and tolerability. ( 2.1 ) The maximum recommended daily dose is 100 mg of sitagliptin and 2,000 mg of metformin HCl. ( 2.1 ) The recommended starting dose in patients not currently treated with metformin is 50 mg sitagliptin and 500 mg metformin HCl twice daily, with gradual dose escalation recommended to reduce gastrointestinal side effects associated with metformin. ( 2.1 ) The starting dose in patients already treated with metformin should provide sitagliptin dosed as 50 mg twice daily (100 mg total daily dose) and the dose of metformin already being taken. For patients taking metformin HCl 850 mg twice daily, the recommended starting dose of ZITUVIMET is 50 mg sitagliptin and 1,000 mg metformin HCl twice daily. ( 2.1 ) Prior to initiation, assess renal function with estimated glomerular filtration rate (eGFR) ( 2.2 ) ○ Do not use in patients with eGFR below 30 mL/min/1.73 m 2 ○ ZITUVIMET is not recommended in patients with eGFR between 30 and less than 45 mL/min/1.73 m 2 . ZITUVIMET may need to be discontinued at time of, or prior to, iodinated contrast imaging procedures. ( 2.3 ) 2.1 Recommended Dosage Take ZITUVIMET orally twice daily with meals. Individualize the dosage of ZITUVIMET on the basis of the patient's current regimen, effectiveness, and tolerability. The maximum recommended daily dose is 100 mg of sitagliptin and 2,000 mg of metformin hydrochloride (HCl). Do not split or divide ZITUVIMET tablets. The recommended starting dose in patients not currently treated with metformin is 50 mg sitagliptin and 500 mg metformin HCl twice daily, with gradual dose escalation recommended to reduce gastrointestinal side effects associated with metformin. The starting dose in patients already treated with metformin should provide sitagliptin dosed as 50 mg twice daily (100 mg total daily dose) and the dose of metformin already being taken. For patients taking metformin HCl 850 mg twice daily, the recommended starting dose of ZITUVIMET is 50 mg sitagliptin and 1,000 mg metformin HCl twice daily. 2.2 Recommendations for Use in Renal Impairment Assess renal function prior to initiation of ZITUVIMET and periodically thereafter. ZITUVIMET is contraindicated in patients with an estimated glomerular filtration rate (eGFR) below 30 mL/min/1.73 m 2 [see Contraindications ( 4 ) and Warnings and Precautions ( 5.1 )]. ZITUVIMET is not recommended in patients with an eGFR between 30 and less than 45 mL/min/1.73 m 2 because these patients require a lower dosage of sitagliptin than what is available in the fixed combination ZITUVIMET product. 2.3 Discontinuation for Iodinated Contrast Imaging Procedures Discontinue ZITUVIMET at the time of, or prior to, an iodinated contrast imaging procedure in patients with an eGFR between 30 and 60 mL/min/1.73 m 2 ; in patients with a history of liver disease, alcoholism, or heart failure; or in patients who will be administered intra-arterial iodinated contrast. Re-evaluate eGFR 48 hours after the imaging procedure; restart ZITUVIMET if renal function is stable [see Warnings and Precautions ( 5.1 )].

6 ADVERSE REACTIONS The following adverse reactions are also discussed elsewhere in the prescribing information: Lactic Acidosis [see Warnings and Precautions ( 5.1 )] Pancreatitis [see Warnings and Precautions ( 5.2 )] Heart Failure [see Warnings and Precautions ( 5.3 )] Acute Renal Failure [see Warnings and Precautions ( 5.4 )] Vitamin B12 Deficiency [see Warnings and Precautions ( 5.5 )] Hypoglycemia with Concomitant Use with Insulin or Insulin Secretagogues [see Warnings and Precautions ( 5.6 )] Hypersensitivity Reactions [see Warnings and Precautions ( 5.7 )] Severe and Disabling Arthralgia [see Warnings and Precautions ( 5.8 )] Bullous Pemphigoid [see Warnings and Precautions ( 5.9 )] Most common adverse reactions (incidence ≥5% of patients simultaneously started on sitagliptin and metformin and more commonly than in patients treated with placebo were diarrhea, upper respiratory tract infection, and headache. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Zydus Pharmaceuticals (USA) Inc. at 1-877-993-8779 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. Common Adverse Reactions Sitagliptin and Metformin Coadministration in Patients with Type 2 Diabetes Mellitus Inadequately Controlled on Diet and Exercise Table 1 summarizes the most common (≥5% of patients) adverse reactions reported in a 24-week placebo-controlled factorial trial in which sitagliptin and metformin were coadministered to patients with type 2 diabetes mellitus inadequately controlled on diet and exercise. Table 1: Sitagliptin and Metformin Coadministered to Patients with Type 2 Diabetes Mellitus Inadequately Controlled on Diet and Exercise: Adverse Reactions Reported in ≥5% of Patients Receiving Combination Therapy (and Greater than in Patients Receiving Placebo) Intent-to-treat population. Number of Patients (%) Placebo Sitagliptin 100 mg once daily Metformin HCl 500 mg/ Metformin HCl 1,000 mg twice daily Data pooled for the patients given the lower and higher doses of metformin. Sitagliptin 50 mg twice daily + Metformin HCl 500 mg/ Metformin HCl 1,000 mg twice daily N = 176 N = 179 N = 364 N = 372 Diarrhea 7 (4) 5 (2.8) 28 (7.7) 28 (7.5) Upper Respiratory Tract 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) Sitagliptin Add-on Therapy in Patients with Type 2 Diabetes Mellitus Inadequately Controlled on Metformin Alone In a 24-week placebo-controlled trial of sitagliptin 100 mg administered once daily added to a twice daily metformin regimen, there were no adverse reactions in ≥5% of patients and more commonly than in patients given placebo. Discontinuation of therapy due to clinical adverse reactions was similar to the placebo treatment group (sitagliptin and metformin, 1.9%; placebo and metformin, 2.5%). Gastrointestinal Adverse Reactions The incidences of pre-selected gastrointestinal adverse experiences in patients treated with sitagliptin and metformin were similar to those reported for patients treated with metformin alone. See Table 2. Table 2: Pre-selected Gastrointestinal Adverse Reactions Reported in Patients with Type 2 Diabetes Mellitus Receiving Sitagliptin and Metformin Number of Patients (%) Trial of Sitagliptin and Metformin in Patients Inadequately Controlled on Diet and Exercise Trial of Sitagliptin Add-on in Patients Inadequately Controlled on Metformin Alone Placebo Sitagliptin 100 mg once daily Metformin HCl 500 mg/ Metformin HCl 1,000 mg twice daily Data pooled for the patients given the lower and higher doses of metformin. Sitagliptin 50 mg twice daily + Metformin HCl 500 mg/ Metformin HCl 1,000 mg twice daily Placebo and Metformin HCl ≥1,500 mg daily Sitagliptin 100 mg once daily and Metformin

5 WARNINGS AND PRECAUTIONS Lactic Acidosis: See boxed warning . ( 5.1 ) Pancreatitis: There have been postmarketing reports of acute pancreatitis, including fatal and non-fatal hemorrhagic or necrotizing pancreatitis. If pancreatitis is suspected, promptly discontinue ZITUVIMET. ( 5.2 ) Heart Failure : Has been observed with two other members of the DPP-4 inhibitor class. Consider risks and benefits of ZITUVIMET in patients who have known risk factors for heart failure. Monitor patients for signs and symptoms. ( 5.3 ) Acute Renal Failure: Has been reported postmarketing, sometimes requiring dialysis. Before initiating ZITUVIMET and at least annually thereafter, assess renal function. ( 5.4 ) Vitamin B 12 Deficiency: Metformin may lower vitamin B 12 levels. Measure hematologic parameters annually and vitamin B 12 at 2 to 3 year intervals and manage any abnormalities. ( 5.5 ) Hypoglycemia with Concomitant Use with Insulin or Insulin Secretagogues: Increased risk of hypoglycemia when used in combination with insulin and/or an insulin secretagogue. A lower dose of insulin or insulin secretagogue may be required. ( 5.6 ) Hypersensitivity Reactions: There have been postmarketing reports of serious allergic and hypersensitivity reactions in patients treated with sitagliptin such as anaphylaxis, angioedema, and exfoliative skin conditions including Stevens-Johnson syndrome. Promptly stop ZITUVIMET, assess for other potential causes, institute appropriate monitoring and treatment. ( 5.7 ) Severe and Disabling Arthralgia: Has been reported in patients taking DPP-4 inhibitors. Consider as a possible cause for severe joint pain and discontinue drug if appropriate. ( 5.8 ) Bullous Pemphigoid: There have been postmarketing reports requiring hospitalization in patients taking DPP-4 inhibitors. Tell patients to report development of blisters or erosions. If bullous pemphigoid is suspected, discontinue ZITUVIMET. ( 5.9 ) 5.1 Lactic Acidosis There have been postmarketing cases of metformin-associated lactic acidosis, including fatal cases. These cases had a subtle onset and were accompanied by nonspecific symptoms such as malaise, myalgias, abdominal pain, respiratory distress, or increased somnolence; however, hypothermia, hypotension and resistant bradyarrhythmias have occurred with severe acidosis. Metformin-associated lactic acidosis was characterized by elevated blood lactate concentrations (>5 mmol/Liter), anion gap acidosis (without evidence of ketonuria or ketonemia), and an increased lactate/pyruvate ratio; metformin plasma levels were generally >5 mcg/mL. Metformin decreases liver uptake of lactate increasing lactate blood levels which may increase the risk of lactic acidosis, especially in patients at risk. If metformin-associated lactic acidosis is suspected, general supportive measures should be instituted promptly in a hospital setting, along with immediate discontinuation of ZITUVIMET. In ZITUVIMET treated patients with a diagnosis or strong suspicion of lactic acidosis, prompt hemodialysis is recommended to correct the acidosis and remove accumulated metformin (metformin HCl is dialyzable, with a clearance of up to 170 mL/min under good hemodynamic conditions). Hemodialysis has often resulted in reversal of symptoms and recovery. Educate patients and their families about the symptoms of lactic acidosis and if these symptoms occur instruct them to discontinue ZITUVIMET and report these symptoms to their health care provider. For each of the known and possible risk factors for metformin-associated lactic acidosis, recommendations to reduce the risk of and manage metformin-associated lactic acidosis are provided below: Renal Impairment The postmarketing metformin-associated lactic acidosis cases primarily occurred in patients with significant renal impairment. The risk of metformin accumulation and metformin-associated lactic acidosis increases with the severity of renal impairment because metformin is substantially excreted by the

4 CONTRAINDICATIONS Severe renal impairment: (eGFR below 30 mL/min/1.73 m 2 ) ( 4) Metabolic acidosis, including diabetic ketoacidosis. ( 4 ) History of a serious hypersensitivity reaction to ZITUVIMET, sitagliptin, or metformin, such as anaphylaxis or angioedema. (4) ZITUVIMET is contraindicated in patients with: Severe renal impairment (eGFR below 30 mL/min/1.73 m 2 ) [see Warnings and Precautions ( 5.1 )]. Acute or chronic metabolic acidosis, including diabetic ketoacidosis. History of a serious hypersensitivity reaction to sitagliptin, metformin, or any of the excipients in ZITUVIMET. Serious hypersensitivity reactions including anaphylaxis or angioedema have been reported. [see Warnings and Precautions ( 5.7 ) and Adverse Reactions ( 6.2 )].

10 OVERDOSAGE In the event of overdose with ZITUVIMET, consider contacting the Poison Help Line (1-800-222-1222) or a medical toxicologist for additional overdosage management recommendations. Employ the usual supportive measures dictated by the patient's clinical status. Per clinical judgement, consider removal of unabsorbed material from the gastrointestinal tract, and clinical monitoring (including obtaining an ECG). Sitagliptin is modestly dialyzable. In clinical studies, approximately 13.5% of the dose was removed over a 3- to 4-hour hemodialysis session. Prolonged hemodialysis may be considered if clinically appropriate. It is not known if sitagliptin is dialyzable by peritoneal dialysis. Overdose of metformin has occurred, including ingestion of amounts greater than 50 grams. Hypoglycemia was reported in approximately 10% of cases, but no causal association with metformin has been established. Lactic acidosis has been reported in approximately 32% of metformin overdose cases [see Warnings and Precautions ( 5.1 )]. Metformin is dialyzable with a clearance of up to 170 mL/min under good hemodynamic conditions. Therefore, hemodialysis may be useful for removal of accumulated drug from patients in whom metformin overdosage is suspected.