Sitagliptin and Metformin Hydrochloride

1 INDICATIONS AND USAGE Sitagliptin and metformin hydrochloride is indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. Limitations of Use Sitagliptin and metformin hydrochloride should not be used in patients with type 1 diabetes mellitus. Sitagliptin and metformin hydrochloride have 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 sitagliptin and metformin hydrochloride. [see Warnings and Precautions ( 5.2 )] Sitagliptin and metformin hydrochloride tablets are 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: • Sitagliptin and metformin hydrochloride tablets should not be used in patients with type 1 diabetes. ( 1 ) • Sitagliptin and metformin hydrochloride tablets have not been studied in patients with a history of pancreatitis. ( 1 , 5.2 )

2 DOSAGE AND ADMINISTRATION • Take sitagliptin and metformin hydrochloride tablets orally twice daily with meals. ( 2.1 ) • Individualize the dosage of sitagliptin and metformin hydrochloride tablets 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 sitagliptin and metformin hydrochloride tablets is 50 mg and 1,000 mg metformin HCl twice daily. ( 2.1 ) • Prior to initiation, assess renal function with estimated glomerular filtration rate (eGFR) ( 2.2 ) o Do not use in patients with eGFR below 30 mL/min/1.73 m 2 . o Sitagliptin and metformin hydrochloride tablets are not recommended in patients with eGFR between 30 and less than 45 mL/min/1.73 m 2 . • Sitagliptin and metformin hydrochloride tablets may need to be discontinued at time of, or prior to, iodinated contrast imaging procedures. ( 2.3 ) 2.1 Recommended Dosing • Take sitagliptin and metformin hydrochloride tablets orally twice daily with meals. • Individualize the dosage of sitagliptin and metformin hydrochloride tablets 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 sitagliptin and metformin hydrochloride 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 sitagliptin and metformin hydrochloride tablets 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 sitagliptin and metformin hydrochloride tablets and periodically thereafter. • Sitagliptin and metformin hydrochloride 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 )]. • Sitagliptin and metformin hydrochloride tablets are 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 sitagliptin and metformin hydrochloride product. 2.3 Discontinuation for Iodinated Contrast Imaging Procedures Discontinue sitagliptin and metformin hydrochloride tablets 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 sitagliptin and metformin hydrochloride tablets if renal function is stable [see Warnings and Precautions ( 5.1 )].

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 sitagliptin and metformin hydrochloride. ( 5.2 ) • Heart Failure: Has been observed with two other members of the DPP-4 inhibitor class. Consider risks and benefits of sitagliptin and metformin hydrochloride 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 sitagliptin and metformin hydrochloride 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 sitagliptin and metformin hydrochloride, 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 sitagliptin and metformin hydrochloride. ( 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 sitagliptin and metformin hydrochloride. In sitagliptin and metformin hydrochloride-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 sitagliptin and metformin hydrochloride 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 lacti…

4 CONTRAINDICATIONS Sitagliptin and metformin hydrochloride 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 and metformin hydrochloride, sitagliptin, or metformin, such as anaphylaxis or angioedema. [see Warnings and Precautions ( 5.7 ); Adverse Reactions ( 6.2 ).] • 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 sitagliptin and metformin hydrochloride, sitagliptin, or metformin, such as anaphylaxis or angioedema. ( 5.7 , 6.2 )

7 DRUG INTERACTIONS Table 4 presents clinically significant drug interactions with sitagliptin and metformin hydrochloride: Table 4: Clinically Significant Drug Interactions with Sitagliptin and Metformin Hydrochloride Tablets Carbonic Anhydrase Inhibitors Clinical Impact: Carbonic anhydrase inhibitors frequently cause a decrease in serum bicarbonate and induce non-anion gap, hyperchloremic metabolic acidosis. Concomitant use of these drugs with sitagliptin and metformin hydrochloride may increase the risk for lactic acidosis. Intervention: Consider more frequent monitoring of these patients. Examples: Topiramate, zonisamide, acetazolamide or dichlorphenamide. Drugs that Reduce Metformin Clearance Clinical Impact: Concomitant use of drugs that interfere with common renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2] / multidrug and toxin extrusion [MATE] inhibitors) could increase systemic exposure to metformin and may increase the risk for lactic acidosis [see Clinical Pharmacology ( 12.3 )] . Intervention: Consider the benefits and risks of concomitant use with sitagliptin and metformin hydrochloride. Examples: Ranolazine, vandetanib, dolutegravir, and cimetidine. Alcohol Clinical Impact: Alcohol is known to potentiate the effect of metformin on lactate metabolism. Intervention: Warn patients against alcohol intake while receiving sitagliptin and metformin hydrochloride. Insulin Secretagogues or Insulin Clinical Impact: Coadministration of sitagliptin and metformin hydrochloride with an insulin secretagogue (e.g., sulfonylurea) or insulin may increase the risk of hypoglycemia. Intervention: Patients receiving an insulin secretagogue or insulin may require lower doses of the insulin secretagogue or insulin. Drugs Affecting Glycemic Control Clinical Impact: Certain drugs tend to produce hyperglycemia and may lead to loss of glycemic control. Intervention: When such drugs are administered to a patient receiving sitagliptin and metformin hydrochloride, observe the patient closely for loss of blood glucose control. When such drugs are withdrawn from a patient receiving sitagliptin and metformin hydrochloride, observe the patient closely for hypoglycemia. Examples: Thiazides and other diuretics, corticosteroids, phenothiazines, thyroid products, estrogens, oral contraceptives, phenytoin, nicotinic acid, sympathomimetics, calcium channel blockers, and isoniazid. • Carbonic anhydrase inhibitors may increase risk of lactic acidosis. Consider more frequent monitoring. ( 7 ) • Drugs that reduce metformin clearance (such as ranolazine, vandetanib, dolutegravir, and cimetidine) may increase the accumulation of metformin. Consider the benefits and risks of concomitant use. ( 7 ) • Alcohol can potentiate the effect of metformin on lactate metabolism. Warn patients against excessive alcohol intake. ( 7 )

8.1 Pregnancy Risk Summary The limited available data with sitagliptin and metformin hydrochloride in pregnant women are not sufficient to inform a drug-associated risk for major birth defects and miscarriage. Published studies with metformin use during pregnancy have not reported a clear association with metformin and major birth defect or miscarriage risk [see Data] . There are risks to the mother and fetus associated with poorly controlled diabetes in pregnancy [see Clinical Considerations] . No adverse developmental effects were observed when sitagliptin was administered to pregnant rats and rabbits during organogenesis at oral doses up to 30-times and 20-times, respectively, the 100 mg clinical dose, based on AUC. No adverse developmental effects were observed when metformin was administered to pregnant Sprague Dawley rats and rabbits during organogenesis at doses up to 2-and 6-times, respectively, a 2,000 mg clinical dose, based on body surface area [see Data] . The estimated background risk of major birth defects is 6-10% in women with pre-gestational diabetes with a Hemoglobin A1c >7% and has been reported to be as high as 20-25% in women with a Hemoglobin A1c >10%. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20% respectively. Clinical Considerations Disease-Associated Maternal and/or Embryo/Fetal Risk Poorly controlled diabetes in pregnancy increases the maternal risk for diabetic ketoacidosis, pre-eclampsia, spontaneous abortions, preterm delivery, and delivery complications. Poorly controlled diabetes increases the fetal risk for major birth defects, still birth, and macrosomia related morbidity. Data Human Data Published data from post-marketing studies do not report a clear association with metformin and major birth defects, miscarriage, or adverse maternal or fetal outcomes when metformin is used during pregnancy. However, these studies cannot definitely establish the absence of any risk because of methodological limitations, including small sample size and inconsistent comparator groups. Animal Data Sitagliptin and Metformin No animal reproduction studies were conducted with the coadministration of sitagliptin and metformin. Sitagliptin In embryo-fetal development studies, sitagliptin administered to pregnant rats and rabbits during organogenesis (gestation day 6 to 20) did not adversely affect developmental outcomes at oral doses up to 250 mg/kg (30-times the 100 mg clinical dose) and 125 mg/kg (20-times the 100 mg clinical dose), respectively, based on AUC. Higher doses in rats associated with maternal toxicity increased the incidence of rib malformations in offspring at 1,000 mg/kg, or approximately 100-times the clinical dose, based on AUC. Placental transfer of sitagliptin was observed in pregnant rats and rabbits. Sitagliptin administered to female rats from gestation day 6 to lactation day 21 caused no functional or behavioral toxicity in offspring of rats at doses up to 1,000 mg/kg. Metformin Metformin did not cause adverse developmental effects when administered to pregnant Sprague Dawley rats and rabbits up to 600 mg/kg/day during the period of organogenesis. This represents an exposure of about 2-and 6-times a 2,000 mg clinical dose based on body surface area (mg/m 2 ) for rats and rabbits, respectively.

6 ADVERSE REACTIONS The following adverse reactions are also discussed elsewhere in the labeling: • 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 )] • The most common adverse reactions reported in ≥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 Sandoz Inc., at 1-800-525-8747 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. Sitagliptin and Metformin Coadministration in Patients with Type 2 Diabetes Inadequately Controlled on Diet and Exercise Table 1 summarizes the most common (≥5% of patients) adverse reactions reported (regardless of investigator assessment of causality) in a 24-week placebo-controlled factorial study in which sitagliptin and metformin were coadministered to patients with type 2 diabetes inadequately controlled on diet and exercise. Table 1: Sitagliptin and Metformin Coadministered to Patients with Type 2 Diabetes Inadequately Controlled on Diet and Exercise: Adverse Reactions Reported (Regardless of Investigator Assessment of Causality) in ≥5% of Patients Receiving Combination Therapy (and Greater than in Patients Receiving Placebo) * Table 1: Sitagliptin and Metformin Coadministered to Patients with Type 2 Diabetes Inadequately Controlled on Diet and Exercise: Adverse Reactions Reported (Regardless of Investigator Assessment of Causality) in ≥5% of Patients Receiving Combination Therapy (and Greater than in Patients Receiving Placebo) * Number of Patients (%) Placebo Sitagliptin 100 mg once daily Metformin HCl 500 mg/ Metformin HCl 1,000 mg twice daily † 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 (4.0) 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) * Intent-to-treat population. † Data pooled for the patients given the lower and higher doses of metformin. Sitagliptin Add-on Therapy in Patients with Type 2 Diabetes 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 reported regardless of investigator assessment of causality 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 (Regardless of Investigator Assessment of Causality) Reported in Patients with Type 2 Diabetes Receiving Sitagliptin and Metformin Table 2: Pre-selected Gastrointestinal Adverse Reactions (Regardless of Investi…