Exenatide

12.1 Mechanism of Action Incretins, such as glucagon-like peptide-1 (GLP-1), enhance glucose-dependent insulin secretion and exhibit other antihyperglycemic actions following their release into the circulation from the gut. BYETTA is a GLP-1 receptor agonist that enhances glucose-dependent insulin secretion by the pancreatic beta-cell, suppresses inappropriately elevated glucagon secretion, and slows gastric emptying. The amino acid sequence of exenatide partially overlaps that of human GLP-1. Exenatide has been shown to bind and activate the human GLP-1 receptor in vitro . This leads to an increase in both glucose-dependent synthesis of insulin, and in vivo secretion of insulin from pancreatic beta cells, by mechanisms involving cyclic AMP and/or other intracellular signaling pathways. BYETTA improves glycemic control by reducing fasting and postprandial glucose concentrations in patients with type 2 diabetes through the actions described below.

1 INDICATIONS AND USAGE BYETTA is indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. Limitations of Use • BYETTA contains exenatide. Coadministration with other exenatide-containing products is not recommended. BYETTA (exenatide) is a glucagon-like peptide-1 (GLP-1) receptor agonist indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. ( 1 , 14 ) Limitations of Use • Coadministration with other exenatide-containing products is not recommended ( 1 ).

2 DOSAGE AND ADMINISTRATION • Inject subcutaneously within 60 minutes prior to morning and evening meals (or before the two main meals of the day, approximately 6 hours or more apart). ( 2.1 ) • Initiate at 5 mcg per dose twice daily; increase to 10 mcg twice daily after 1 month based on clinical response. ( 2.1 ) 2.1 Recommended Dosing • Initiate BYETTA at 5 mcg administered subcutaneously twice daily at any time within the 60-minute period before the morning and evening meals (or before the two main meals of the day, approximately 6 hours or more apart). Do not administer after a meal. • Based on clinical response, the dose of BYETTA can be increased to 10 mcg twice daily which is recommended after 1 month of therapy, in order to reduce the risk of gastrointestinal adverse reactions [see Warnings and Precautions (5.5) and Adverse Reactions (6.1) ] . • Administer as a subcutaneous injection in the thigh, abdomen, or upper arm. • Rotate injections sites with each dose. Do not use the same site for each injection. • Inspect visually for particulate matter and discoloration. Only use BYETTA if the solution appears clear, colorless, and contains no particles. • When using BYETTA with insulin, administer as separate injections and never mix. It is acceptable to inject BYETTA and insulin in the same body region, but the injections should not be adjacent to each other. • If a dose is missed, resume the treatment regimen as prescribed with the next scheduled dose.

6 ADVERSE REACTIONS The following serious adverse reactions are described below or elsewhere in the prescribing information: • Acute Pancreatitis [see Warnings and Precautions (5.1) ] • Never Share a BYETTA Pen Between Patients [see Warnings and Precautions (5.2) ] • Hypoglycemia with Concomitant Use of Insulin Secretagogues or Insulin [see Warnings and Precautions (5.3) ] • Acute Kidney Injury Due to Volume Depletion [see Warnings and Precautions (5.4) ] • Severe Gastrointestinal Adverse Reactions [see Warnings and Precautions (5.5) ] • Immunogenicity [see Warnings and Precautions (5.6) ] • Hypersensitivity [see Warnings and Precautions (5.7) ] • Drug-Induced Thrombocytopenia [see Warnings and Precautions (5.8) ] • Acute Gallbladder Disease [see Warnings and Precautions (5.9) ] • Pulmonary Aspiration During General Anesthesia or Deep Sedation [see Warnings and Precautions (5.10) ] • Most common (≥5%) and occurring more frequently than placebo in clinical trials: nausea, hypoglycemia, vomiting, diarrhea, feeling jittery, dizziness, headache, dyspepsia, constipation, asthenia. Nausea usually decreases over time. ( 5.3 , 6 ) To report SUSPECTED ADVERSE REACTIONS, contact AstraZeneca at 1-800-236-9933 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trial 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. Hypoglycemia Table 1 summarizes the incidence and rate of hypoglycemia with BYETTA in six placebo-controlled clinical trials. Table 1: Incidence (%) and Rate of Hypoglycemia when BYETTA was used as Monotherapy or with Concomitant Antidiabetic Therapy in Six Placebo-Controlled Clinical Trials A hypoglycemic episode was recorded if a patient reported symptoms of hypoglycemia with or without a blood glucose value consistent with hypoglycemia. Severe hypoglycemia was defined as an event with symptoms consistent with hypoglycemia requiring the assistance of another person and associated with either a documented blood glucose value <54 mg/dL or prompt recovery after treatment for hypoglycemia. Placebo BID BYETTA 5 mcg BID BYETTA 10 mcg BID Monotherapy (24 Weeks) N 77 77 78 % Overall 1.3% 5.2% 3.8% Rate (episodes/patient-year) 0.03 0.21 0.52 % Severe 0.0% 0.0% 0.0% With Metformin (30 Weeks) N 113 110 113 % Overall 5.3% 4.5% 5.3% Rate (episodes/patient-year) 0.12 0.13 0.12 % Severe 0.0% 0.0% 0.0% With a Sulfonylurea (30 Weeks) N 123 125 129 % Overall 3.3% 14.4% 35.7% Rate (episodes/patient-year) 0.07 0.64 1.61 % Severe 0.0% 0.0% 0.0% With Metformin and a Sulfonylurea (30 Weeks) N 247 245 241 % Overall 12.6% 19.2% 27.8% Rate (episodes/patient-year) 0.58 0.78 1.71 % Severe 0.0% 0.4% 0.0% With a Thiazolidinedione (16 Weeks) N 112 not evaluated 121 % Overall 7.1% not evaluated 10.7% Rate (episodes/patient-years) 0.56 not evaluated 0.98 % Severe 0.0% not evaluated 0.0% With Insulin Glargine with or without Metformin and/or Thiazolidinedione (30 Weeks) When BYETTA was initiated in combination with insulin glargine, the dose of insulin glargine was decreased by 20% in patients with an HbA 1c ≤8.0% to minimize the risk of hypoglycemia. See Table 9 for insulin dose titration algorithm. N 122 not evaluated 137 % Overall 29.5% not evaluated 24.8% Rate (episodes/patient-years) 1.58 not evaluated 1.61 % Severe 0.8% not evaluated 0.0% N = number of Intent-to-Treat subjects in each treatment group. Immunogenicity Antibodies were assessed in 90% of subjects in the 30-week, 24-week, and 16-week studies of BYETTA. In the 30-week controlled trials of BYETTA add-on to metformin and/or sulfonylurea, antibodies were assessed at 2- to 6-week intervals. The mean antibody titer peaked at Week 6 and was reduced by 55% by Week 30. Three hundred and sixty patients (38%) had low titer antibodies (<625) to exenatide at 30 weeks. The level of glycemic control (HbA 1c ) in these patients was generally comparable to that observed in the 534 patients (56%) without antibody titers. An additional 59 patients (6%) had higher titer antibodies (≥625) at 30 weeks. Of these patients, 32 (3% overall) had an attenuated glycemic response to BYETTA; the remaining 27 (3% overall) had a glycemic response comparable to that of patients without antibodies. In the 16-week trial of BYETTA add-on to thiazolidinediones, with or without metformin, 36 patients (31%) had low titer antibodies to exenatide at 16 weeks. The level of glycemic control in these patients was generally comparable to that observed in the 69 patients (60%) without antibody titer. An additional 10 patients (9%) had higher titer antibodies at 16 weeks. Of these patients, 4 (4% overall) had an attenuated glycemic response to BYETTA; the remaining 6 (5% overall) had a glycemic response comparable to that of patients without antibodies. In the 24-week trial of BYETTA u

7 DRUG INTERACTIONS • May impact absorption of orally administered medications. ( 7 ) • Warfarin: Postmarketing reports of increased INR sometimes associated with bleeding. Monitor INR frequently until stable upon initiation or alteration of BYETTA therapy. ( 7 ) Generic Section Table 6: Clinically Relevant Interactions with BYETTA Concomitant Use of Insulin Secretagogues or Insulin Clinical Impact Exenatide promotes insulin release from pancreatic beta-cells in the presence of elevated glucose concentrations. The risk of hypoglycemia is increased when exenatide is used in combination with insulin secretagogues (e.g., sulfonylureas) or insulin [see Warnings and Precautions (5.3) and Adverse Reactions (6) ] . Intervention When initiating BYETTA, consider reducing the dose of concomitantly administered insulin secretagogue or insulin to reduce the risk of hypoglycemia. Warfarin Clinical Impact In a drug interaction study, BYETTA did not have a significant effect on INR [see Clinical Pharmacology (12.3) ] . There have been postmarketing reports for BYETTA of increased INR with concomitant use of warfarin, sometimes associated with bleeding [see Adverse Reactions (6.2) ] . Intervention In patients taking warfarin, the prothrombin time should be monitored more frequently after initiation or alteration of BYETTA therapy. Once a stable prothrombin time has been documented, the prothrombin time can be monitored at the intervals recommended for patients taking warfarin. Orally Administered Drugs (e.g., acetaminophen) Clinical Impact Exenatide slows gastric emptying. Therefore, BYETTA has the potential to reduce the rate of absorption of orally administered drugs [see Clinical Pharmacology (12.3) ]. Intervention Use caution when administering oral medications with BYETTA where a slower rate of oral absorption may be clinically meaningful. For oral medications that are dependent on threshold concentrations for efficacy, such as contraceptives and antibiotics, patients should be advised to take those drugs at least 1 hour before BYETTA injection. If such drugs are to be administered with food, patients should be advised to take them with a meal or snack when BYETTA is not administered [see Clinical Pharmacology (12.3) ] .