JANUMET

Boxed Warning 8/2026 Warnings and Precautions, Lactic Acidosis ( 5.1 ) 8/2026

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

2 DOSAGE AND ADMINISTRATION Take JANUMET orally twice daily with meals. ( 2.1 ) Individualize the dosage of JANUMET 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. ( 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 JANUMET is 50 mg sitagliptin and 1000 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 . JANUMET is not recommended in patients with eGFR between 30 and less than 45 mL/min/1.73 m 2 . JANUMET may need to be discontinued at time of, or prior to, iodinated contrast imaging procedures. ( 2.3 ) 2.1 Recommended Dosing Take JANUMET orally twice daily with meals. Individualize the dosage of JANUMET 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). Do not split or divide JANUMET 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 JANUMET is 50 mg sitagliptin and 1000 mg metformin HCl twice daily. 2.2 Recommendations for Use in Renal Impairment Assess renal function prior to initiation of JANUMET and periodically thereafter. JANUMET 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) ] . JANUMET 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 JANUMET product. 2.3 Discontinuation for Iodinated Contrast Imaging Procedures Discontinue JANUMET 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 if renal function is stable [see Warnings and Precautions (5.1) ] .

3 DOSAGE FORMS AND STRENGTHS Tablets: sitagliptin 50 mg and metformin HCl 500 mg tablets are light pink, capsule-shaped, film-coated tablets with “575” debossed on one side. sitagliptin 50 mg and metformin HCl 1000 mg tablets are red, capsule-shaped, film-coated tablets with “577” debossed on one side. JANUMET Tablets: sitagliptin 50 mg and metformin HCl 500 mg tablets sitagliptin 50 mg and metformin HCl 1000 mg tablets ( 3 )

4 CONTRAINDICATIONS JANUMET 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 JANUMET, sitagliptin, or metformin, such as anaphylaxis or angioedema [see Warnings and Precautions (5.7) and 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 JANUMET, sitagliptin, or metformin, such as anaphylaxis or angioedema. ( 5.7 , 6.2 )

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 B 12 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 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. 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) Intent-to-treat population. Number of Patients (%) Placebo Sitagliptin 100 mg once daily Metformin HCl 500 mg/ Metformin HCl 1000 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 1000 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) 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 Number of Patients (%) Study of Sitagliptin and Metformin in Patients Inadequately Controlled on Diet and Exercise Study of Sitagliptin Add-on in Patients Inadequately Controlled on Metformin Alone Placebo Sitagliptin 100 mg once daily Metformin HCl 500 mg/ Metformin HCl 1000 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 …

7 DRUG INTERACTIONS Table 4 presents clinically significant drug interactions with JANUMET: Table 4: Clinically Significant Drug Interactions with JANUMET 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 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. 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. Insulin Secretagogues or Insulin Clinical Impact: Coadministration of JANUMET 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, observe the patient closely for loss of blood glucose control. When such drugs are withdrawn from a patient receiving JANUMET, 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 USE IN SPECIFIC POPULATIONS Females and Males of Reproductive Potential: Advise premenopausal females of the potential for an unintended pregnancy. ( 8.3 ) Geriatric Use: Assess renal function more frequently. ( 8.5 ) Hepatic Impairment: Avoid use in patients with hepatic impairment. ( 8.7 ) 8.1 Pregnancy Risk Summary The limited available data with JANUMET 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 2000 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 1000 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 1000 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 2000 mg clinical dose based on body surface area (mg/m 2 ) for rats and rabbits, respectively. 8.2 Lactation Risk Summary There is no information regarding the presence of JANUMET in human milk, the effects on the breastfed infant, or the effects on milk production. Limited published studies report that metformin is present in human milk [see Data ] . There are no reports of adverse effects on breastfed infants exposed to metfor …

12.1 Mechanism of Action JANUMET JANUMET combines two antihyperglycemic agents with complementary mechanisms of action to improve glycemic control in patients with type 2 diabetes mellitus: sitagliptin, a dipeptidyl peptidase-4 (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 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.

11 DESCRIPTION JANUMET (sitagliptin and metformin HCl) tablets for oral use contain two antihyperglycemic drugs: sitagliptin and metformin HCl. Sitagliptin Sitagliptin is an orally-active inhibitor of the dipeptidyl peptidase-4 (DPP-4) enzyme. Sitagliptin is present in JANUMET tablets in the form of sitagliptin phosphate monohydrate. Sitagliptin phosphate monohydrate is described chemically as 7-[(3 R )-3-amino-1-oxo-4-(2,4,5-trifluorophenyl)butyl]-5,6,7,8-tetrahydro-3-(trifluoromethyl)-1,2,4-triazolo[4,3- a ]pyrazine phosphate (1:1) monohydrate with an empirical formula of C 16 H 15 F 6 N 5 O∙H 3 PO 4 ∙H 2 O and a molecular weight of 523.32. The structural formula is: Sitagliptin phosphate monohydrate is a white to off-white, crystalline, non-hygroscopic powder. It is soluble in water and N,N-dimethyl formamide; slightly soluble in methanol; very slightly soluble in ethanol, acetone, and acetonitrile; and insoluble in isopropanol and isopropyl acetate. sitagliptin chemical structure Metformin HCl Metformin HCl ( N , N -dimethylimidodicarbonimidic diamide hydrochloride) is not chemically or pharmacologically related to any other classes of oral antihyperglycemic agents. Metformin HCl is a white to off-white crystalline compound with a molecular formula of C 4 H 11 N 5 ∙HCl and a molecular weight of 165.63. Metformin HCl is freely soluble in water and is practically insoluble in acetone, ether, and chloroform. The pK a of metformin HCl is 12.4. The pH of a 1% aqueous solution of metformin HCl is 6.68. The structural formula is as shown: metformin hydrochloride chemical structure JANUMET JANUMET is available as film-coated tablets containing: 64.25 mg sitagliptin monohydrate equivalent to 50 mg of sitagliptin and 389.93 mg of metformin equivalent to 500 mg metformin HCl (JANUMET 50/500). 64.25 mg sitagliptin monohydrate equivalent to 50 mg of sitagliptin and 779.86 mg of metformin equivalent to 1000 mg metformin HCl (JANUMET 50/1000). Each film-coated tablet of JANUMET contains the following inactive ingredients: microcrystalline cellulose, polyvinylpyrrolidone, sodium lauryl sulfate, and sodium stearyl fumarate. In addition, the film coating contains the following inactive ingredients: polyvinyl alcohol, polyethylene glycol, talc, titanium dioxide, red iron oxide, and black iron oxide.

10 OVERDOSAGE In the event of overdose with JANUMET, contact the Poison Control Center. In the event of an overdose, it is reasonable to employ supportive measures, e.g., remove unabsorbed material from the gastrointestinal tract, employ clinical monitoring (including obtaining an electrocardiogram), and institute supportive therapy as indicated by the patient's clinical status. 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.

16 HOW SUPPLIED/STORAGE AND HANDLING Tablets supplied as follows: Contents Description How Supplied NDC 50 mg sitagliptin and 500 mg metformin HCl light pink, capsule-shaped, film-coated tablets with “575” debossed on one side unit-of-use bottles of 60 NDC 0006-0575-61 unit-of-use bottles of 180 NDC 0006-0575-62 bulk bottles of 1000 NDC 0006-0575-82 50 mg sitagliptin and 1000 mg metformin HCl red, capsule-shaped, film-coated tablets with “577” debossed on one side unit-of-use bottles of 60 NDC 0006-0577-61 unit-of-use bottles of 180 NDC 0006-0577-62 bulk bottles of 1000 NDC 0006-0577-82 Store at 20-25°C (68-77°F), excursions permitted to 15-30°C (59-86°F). [See USP Controlled Room Temperature.]