Sitagliptin for Diabetes Complications

INDICATIONS AND USAGE Sitagliptin and metformin hydrochloride tablets 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: Sitagliptin and metformin hydrochloride tablets is not recommended in patients with type 1 diabetes mellitus. ( 1 ) Sitagliptin and metformin hydrochloride tablets has not been studied in patients with a history of pancreatitis. ( 1 ) Sitagliptin and metformin hydrochloride tablets 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 tablets is not recommended in patients with type 1 diabetes mellitus. Sitagliptin and metformin hydrochloride tablets 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 sitagliptin and metformin hydrochloride tablets. [see Warnings and Precautions ( 5.2 )].

DOSAGE AND ADMINISTRATION Take JANUMET XR orally once daily with a meal. Patients taking two JANUMET XR tablets should take the tablets together. ( 2.1 ) Individualize the dosage of JANUMET XR 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 2000 mg of metformin HCl extended-release. ( 2.1 ) The recommended starting dose in patients not currently treated with metformin is 100 mg sitagliptin and 1000 mg metformin HCl once daily, with gradual dose escalation recommended to reduce the gastrointestinal effects due to metformin. ( 2.1 ) The starting dose in patients already treated with metformin should provide sitagliptin dosed as 100 mg and the dose of metformin already being taken once daily. For patients taking metformin HCl 850 mg twice daily or 1000 mg twice daily, the recommended starting dose of JANUMET XR is two 50 mg sitagliptin and 1000 mg metformin HCl extended-release tablets once daily. ( 2.1 ) Maintain the same total daily dose of sitagliptin and metformin when changing between JANUMET and JANUMET XR. ( 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 . Discontinue if eGFR later falls below 30 mL/min/1.73 m 2 . Initiation is not recommended in patients with eGFR between 30 – 45 mL/min/1.73 m 2 . Assess risk/benefit of continuing if eGFR falls below 45 mL/min/1.73 m 2 . Limit dose of sitagliptin to 50 mg once daily if eGFR falls below 45 mL/min/1.73 m 2 . JANUMET XR may need to be discontinued at time of, or prior to, iodinated contrast imaging procedures. ( 2.3 ) 2.1 Recommended Dosing Take JANUMET XR orally once daily with a meal. Patients taking two JANUMET XR tablets should take the two tablets together once daily. Individualize the dosage of JANUMET XR on the basis of the patient’s current regimen, effectiveness, and tolerability. The maximum recommended daily dose is 100 mg of sitagliptin and 2000 mg of metformin hydrochloride (HCl) extended-release. The recommended starting dose in patients not currently treated with metformin is 100 mg sitagliptin and 1000 mg metformin HCl extended-release once 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 100 mg sitagliptin and the previously prescribed dose of metformin. For patients taking metformin HCl immediate-release 850 mg twice daily or 1000 mg twice daily, the recommended starting dose of JANUMET XR is two 50 mg sitagliptin and 1000 mg metformin HCl extended-release tablets taken together once daily. Maintain the same total daily dose of sitagliptin and metformin when changing between JANUMET (sitagliptin and metformin HCl immediate-release) and JANUMET XR. Do not split, crush or chew JANUMET XR tablets. 2.2 Recommendations for Use in Renal Impairment Assess renal function prior to initiation of JANUMET XR and periodically thereafter. JANUMET XR is contraindicated in patients with an estimated glomerular filtration rate (eGFR) below 30 mL/min/1.73 m 2 . Discontinue JANUMET XR if the patient's eGFR later falls below 30 mL/min/1.73 m 2 [see Contraindications (4) and Warnings and Precautions (5.1) ] . Initiation of JANUMET XR in patients with an eGFR between 30 and 45 mL/min/1.73 m 2 is not recommended. In patients taking JANUMET XR whose eGFR later falls below 45 mL/min/1.73 m 2 , assess the benefit risk of continuing therapy and limit dose of the sitagliptin component to 50 mg once daily. 2.3 Discontinuation for Iodinated Contrast Imaging Procedures Discontinue JANUMET XR 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 JANUMET XR if renal function is stable [see Warnings and Precautions (5.1) ] .

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 kidney. Clinical recommendations based upon the patient's renal function include [see Dosage and Administration ( 2.2 ) and Clinical Pharmacology ( 12.3 )]: Before initiating ZITUVIMET, obtain an estimated glomerular filtration rate (eGFR). ZITUVIMET is contraindicated in patients with an eGFR below 30 mL/min/1.73 m 2 [see Contraindications ( 4 )]. 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. Obtain an eGFR at least annually in all patients taking ZITUVIMET. In patients at increased risk for the development of renal impairment (e.g., the elderly), renal function should be assessed more frequently. Drug Interactions The concomitant use of ZITUVIMET with specific drugs may increase the risk of metformin-associated lactic acidosis: those that impair renal function, result in significant hemodynamic change, interfere with acid-base balance or increase metformin accumulation [see Drug Interactions ( 7 )]. Therefore, consider more frequent monitoring of patients. Age 65 or Greater The risk of metformin-associated lactic acidosis increases with the patient's age because elderly patients have a greater likelihood of having hepatic, renal, or cardiac impairment than younger patients. Assess renal function more frequently in elderly patients [see Use in Specific Populations ( 8.5 )]. Radiological Studies with Contrast Administration of intravascular iodinated contrast agents in metformin-treated patients has led to an acute decrease in renal function and the occurrence of lactic acidosis. Stop 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 hepatic impairment, alcoholism, or heart failure; or in patients who will be administered intra-arterial iodinated contrast. Re-evaluate eGFR 48 hours after the imaging procedure, and restart ZITUVIMET if renal function is stable. Surgery and Other Procedures Withholding of food and fluids during surgical or other procedures may increase the risk for volume depletion, hypotension and renal impairment. ZITUVIMET should be temporarily discontinued while patients have restricted food and fluid intake. Hypoxic States Several of the postmarketing cases of metformin-associated lactic acidosis occurred in the setting of acute congestive heart failure (particularly when accompanied by hypoperfusion and hypoxemia). Cardiovascular collapse (shock), acute myocardial infarction, sepsis, and other conditions associated with hypoxemia have been associated with lactic acidosis and may also cause prerenal azotemia. When such events occur, discontinue ZITUVIMET. Excessive Alcohol Intake Alcohol potentiates the effect of metformin on lactate metabolism and this may increase the risk of metformin-associated lactic acidosis. Warn patients against excessive alcohol intake while receiving ZITUVIMET. Hepatic Impairment Patients with hepatic impairment have developed with cases of metformin-associated lactic acidosis. This may be due to impaired lactate clearance resulting in higher lactate blood levels. Therefore, avoid use of ZITUVIMET in patients with clinical or laboratory evidence of hepatic disease. 5.2 Pancreatitis There have been postmarketing reports of acute pancreatitis, including fatal and non-fatal hemorrhagic or necrotizing pancreatitis, in patients taking ZITUVIMET. After initiation of ZITUVIMET, patients should be observed carefully for signs and symptoms of pancreatitis. If pancreatitis is suspected, sitagliptin should promptly be discontinued and appropriate management should be initiated. It is unknown whether patients with a history of pancreatitis are at increased risk for the development of pancreatitis while using ZITUVIMET. 5.3 Heart Failure An association between DPP-4 inhibitor treatment and heart fail

Drug Interactions The concomitant use of JANUMET XR with specific drugs may increase the risk of metformin-associated lactic acidosis: those that impair renal function, result in significant hemodynamic change, interfere with acid-base balance or increase metformin accumulation [see Drug Interactions (7) ]. Therefore, consider more frequent monitoring of patients. 7 DRUG INTERACTIONS Table 4 presents clinically significant drug interactions with JANUMET XR: Table 4: Clinically Significant Drug Interactions with JANUMET XR 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 JANUMET XR 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 [OCT 2 ] / 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 JANUMET XR. 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 JANUMET XR. Insulin Secretagogues or Insulin Clinical Impact: Coadministration of JANUMET XR 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 JANUMET XR, observe the patient closely for loss of blood glucose control. When such drugs are withdrawn from a patient receiving JANUMET XR, 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 )

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 HCl ≥1,500 mg daily N = 176 N = 179 N = 364 N = 372 N = 237 N = 464 Diarrhea 7 (4) 5 (2.8) 28 (7.7) 28 (7.5) 6 (2.5) 11 (2.4) Nausea 2 (1.1) 2 (1.1) 20 (5.5) 18 (4.8) 2 (0.8) 6 (1.3) Vomiting 1 (0.6) 0 (0) 2 (0.5) 8 (2.2) 2 (0.8) 5 (1.1) Abdominal Pain Abdominal discomfort was included in the analysis of abdominal pain in the trial of initial therapy. 4 (2.3) 6 (3.4) 14 (3.8) 11 (3) 9 (3.8) 10 (2.2) Sitagliptin in Combination with Metformin and Glimepiride In a 24-week placebo-controlled trial of sitagliptin 100 mg as add-on therapy in patients with type 2 diabetes mellitus inadequately controlled on metformin and glimepiride (sitagliptin, N=116; placebo, N=113), the adverse reactions reported in ≥5% of patients treated with sitagliptin and more commonly than in patients treated with placebo were: hypoglycemia ( see Table 3) and headache (6.9%, 2.7%). Sitagliptin in Combination with Metformin and Rosiglitazone In a placebo-controlled trial of sitagliptin 100 mg as add-on therapy in patients with type 2 diabetes mellitus inadequately controlled on metformin and rosiglitazone (sitagliptin, N=181; placebo, N=97), the adverse reactions reported through Week 18 in ≥5% of patients treated with sitagliptin and more commonly than in patients treated with placebo were: upper respiratory tract infection (sitagliptin, 5.5%; placebo, 5.2%) and nasopharyngitis (6.1%, 4.1%). Through Week 54, the adverse reactions reported in ≥5% of patients treated with sitagliptin and more commonly than in patients treated with placebo were: upper respiratory tract infection (sitagliptin, 15.5%; placebo, 6.2%), nasopharyngitis (11%, 9.3%), peripheral edema (8.3%, 5.2%), and headache (5.5%, 4.1%). Sitagliptin in Combination with Metformin and Insulin In a 24-week placebo-controlled trial of sitagliptin 100 mg as add-on therapy in patients with type 2 diabetes mellitus inadequately controlled on metformin and insulin (sitagliptin, N=229; placebo, N=233), the only adverse reaction reported in ≥5% of patients treated with sitagliptin and more commonly than in patients treated with placebo was hypoglycemia (Table 3). Hypoglycemia In the above trials (N=5), adverse reactions of hypoglycemia were based on all reports of symptomatic hypoglycemia; a concurrent glucose measurement was not required although most (77%) reports of hypoglycemia were accompanied by a blood glucose measurement ≤70 mg/dL. When the combination of sitagliptin and metformin was coadministered with a sulfonylurea or with insulin, the percentage of patients reporting at least one adverse reaction of hypoglycemia was higher than that observed with placebo and metformin coadministered with a sulfonylurea or with insulin (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 Trials of Sitagliptin in Combination with Metformin Coadministered with Glimepiride or Insulin Add-On to Glimepiride + Metformin (24 weeks) Sitagliptin 100 mg + Metformin + Glimepiride Placebo + Metformin + Glimepiride N = 116 N = 113 Overall (%) 19 (16.4) 1 (0.9) Rate (episodes/patient-year) Based on total number of events (i.e., a single patient may have had multiple events). 0.82 0.02 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) Add-On to Insulin + Metformin (24 weeks) Sitagliptin 100 mg + Metformin + Insulin Placebo + Metformin + Insulin N = 229 N = 233 Overall (%) 35 (15.3) 19 (8.2) Rate (episodes/patient-year) 0.98 0.61 Severe (%) 1 (0.4) 1 (0.4) The overall incidence of reported adverse reactions of hypoglycemia in patients with type 2 diabetes mellitus inadequately controlled on diet and exercise was 0.6% in patients given placebo, 0.6% in patients given sitagliptin alone, 0.8% in patients given me