Etanercept

12.1 Mechanism of Action TNF is a naturally occurring cytokine that is involved in normal inflammatory and immune responses. It plays an important role in the inflammatory processes of RA, polyarticular JIA, PsA, and AS and the resulting joint pathology. In addition, TNF plays a role in the inflammatory process of PsO. Elevated levels of TNF are found in involved tissues and fluids of patients with RA, JIA, PsA, AS, and PsO. Two distinct receptors for TNF (TNFRs), a 55 kilodalton protein (p55) and a 75 kilodalton protein (p75), exist naturally as monomeric molecules on cell surfaces and in soluble forms. Biological activity of TNF is dependent upon binding to either cell surface TNFR. Etanercept is a dimeric soluble form of the p75 TNF receptor that can bind TNF molecules. Etanercept inhibits binding of TNF-α and TNF-β (lymphotoxin alpha [LT-α]) to cell surface TNFRs, rendering TNF biologically inactive. In in vitro studies, large complexes of etanercept with TNF-α were not detected and cells expressing transmembrane TNF (that binds Enbrel) are not lysed in the presence or absence of complement.

1 INDICATIONS AND USAGE Enbrel is a tumor necrosis factor (TNF) blocker indicated for the treatment of: Adult patients with: Rheumatoid Arthritis (RA) ( 1.1 ) Psoriatic Arthritis (PsA) ( 1.3 ) Ankylosing Spondylitis (AS) ( 1.4 ) Plaque Psoriasis (PsO) ( 1.5 ) Pediatric patients with: Polyarticular Juvenile Idiopathic Arthritis (pJIA), 2 years of age or older ( 1.2 ) Juvenile Psoriatic Arthritis, 2 years of age or older (JPsA) ( 1.6 ) Plaque Psoriasis, 4 years of age or older ( 1.5 ) 1.1 Rheumatoid Arthritis Enbrel is indicated for reducing signs and symptoms, inducing major clinical response, inhibiting the progression of structural damage, and improving physical function in patients with moderately to severely active rheumatoid arthritis (RA). Enbrel can be initiated in combination with methotrexate (MTX) or used alone. 1.2 Polyarticular Juvenile Idiopathic Arthritis Enbrel is indicated for reducing signs and symptoms of moderately to severely active polyarticular juvenile idiopathic arthritis (pJIA) in patients 2 years of age and older. 1.3 Psoriatic Arthritis Enbrel is indicated for reducing signs and symptoms, inhibiting the progression of structural damage of active arthritis, and improving physical function in adult patients with psoriatic arthritis (PsA). Enbrel can be used with or without methotrexate. 1.4 Ankylosing Spondylitis Enbrel is indicated for reducing signs and symptoms in patients with active ankylosing spondylitis (AS). 1.5 Plaque Psoriasis Enbrel is indicated for the treatment of patients 4 years or older with chronic moderate to severe plaque psoriasis (PsO) who are candidates for systemic therapy or phototherapy. 1.6 Juvenile Psoriatic Arthritis Enbrel is indicated for the treatment of active juvenile psoriatic arthritis (JPsA) in pediatric patients 2 years of age and older.

2 DOSAGE AND ADMINISTRATION Enbrel is administered by subcutaneous injection. Patient Population Recommended Dose and Frequency Adult RA and PsA ( 2.3 ) 50 mg once weekly with or without methotrexate (MTX) AS ( 2.3 ) 50 mg once weekly Adult PsO ( 2.3 ) 50 mg twice weekly for 3 months, followed by 50 mg once weekly pJIA, Pediatric PsO and JPsA ( 2.4 ) 0.8 mg/kg weekly, with a maximum of 50 mg per week 2.1 Testing and Procedures Prior to Treatment Initiation Perform the following evaluations and procedures prior to initiating treatment with Enbrel: Prior to initiating Enbrel and periodically during therapy, evaluate patients for active tuberculosis and test for latent infection [see Warnings and Precautions (5.1) ]. Complete all age-appropriate vaccinations as recommended by current immunization guidelines prior to initiating treatment with Enbrel [see Warnings and Precautions (5.8) ]. 2.2 Important Administration Instructions Administration of one 50 mg Enbrel single - dose prefilled syringe, one single - dose prefilled Enbrel SureClick autoinjector, or one Enbrel Mini single - dose prefilled cartridge (for use with the AutoTouch reusable autoinjector only), provides a dose equivalent to two 25 mg Enbrel single-dose prefilled syringes, two 25 mg single - dose vials, or two multiple-dose vials of lyophilized Enbrel, when multiple - dose vials are reconstituted and administered as recommended. 2.3 Recommended Dosage in Adult Patients with Rheumatoid Arthritis, Ankylosing Spondylitis, Psoriatic Arthritis, and Plaque Psoriasis Enbrel is administered by subcutaneous injection (Table 1). Table 1. Recommended Dosage for Adult Patients with RA, AS, PsA and PsO Patient Population Recommended Dosage Adult RA, AS, and PsA 50 mg weekly Adult PsO Starting Dose : 50 mg twice weekly for 3 months Maintenance Dose : 50 mg once weekly See the Enbrel (etanercept) "Instructions for Use" insert for detailed information on injection site selection and dose administration [see Dosage and Administration (2.3) and Patient Counseling Information (17) ] . Adult Rheumatoid Arthritis, Ankylosing Spondylitis, and Psoriatic Arthritis Patients Methotrexate, glucocorticoids, salicylates, nonsteroidal anti-inflammatory drugs (NSAIDs), or analgesics may be continued during treatment with Enbrel. Based on a study of 50 mg Enbrel twice weekly in patients with RA that suggested higher incidence of adverse reactions but similar American College of Rheumatology (ACR) response rates, doses higher than 50 mg per week are not recommended. Adult Plaque Psoriasis Patients In addition to the 50 mg twice weekly recommended starting dose, starting doses of 25 mg or 50 mg per week were shown to be efficacious. The proportion of responders was related to Enbrel dosage [see Clinical Studies (14.5) ] . 2.4 Recommended Dosage for Pediatric Patients with Polyarticular Juvenile Idiopathic Arthritis, Plaque Psoriasis, and Juvenile Psoriatic Arthritis The recommended weight-based dosage for pediatric patients is administered by subcutaneous injection (Table 2). Table 2. Recommended Dosage for Pediatric Patients with pJIA, PsO and JPsA Body Weight Recommended Dosage 63 kg (138 pounds) or more 50 mg weekly Less than 63 kg (138 pounds) 0.8 mg/kg weekly To achieve pediatric doses other than 25 mg or 50 mg, use Enbrel solution in a single-dose vial or reconstituted lyophilized powder in a multiple-dose vial. Dosages of Enbrel higher than those described in Table 2 have not been studied in pediatric patients. In pJIA patients, glucocorticoids, NSAIDs, or analgesics may be continued during treatment with Enbrel. 2.5 Preparation Instructions for Enbrel Enbrel is intended for use under the guidance and supervision of a physician. Patients may self-inject when deemed appropriate and if they receive medical follow-up, as necessary. Patients should not self-administer until they receive proper training in how to prepare and administer the correct dose. Administer injections subcutaneously in the thigh, abdomen or outer area of the upper arm. The Enbrel devices are not made with natural rubber latex. The Enbrel (etanercept) "Instructions for Use" insert for each presentation contains more detailed instructions on injection site selection and the preparation of Enbrel. Preparation of Enbrel Single-dose Prefilled Syringe For a more comfortable injection, leave Enbrel prefilled syringes at room temperature for about 15 to 30 minutes before injecting. DO NOT remove the needle cover while allowing the prefilled syringe to reach room temperature. Inspect visually for particulate matter and discoloration prior to administration. There may be small white particles of protein in the solution. This is not unusual for proteinaceous solutions. The solution should not be used if discolored or cloudy, or if foreign particulate matter is present. When using the Enbrel single-dose prefilled syringe, check to see if the amount of liquid in the prefilled syringe falls between the two purple fil

6 ADVERSE REACTIONS The following serious adverse reactions are discussed in greater detail in other sections of the labeling: Serious Infections [see Warnings and Precautions (5.1) ] Neurologic Reactions [see Warnings and Precautions (5.2) ] Malignancies [see Warnings and Precautions (5.3) ] Patients with Heart Failure [see Warnings and Precautions (5.4) ] Hematologic Reactions [see Warnings and Precautions (5.5) ] Hepatitis B Reactivation [see Warnings and Precautions (5.6) ] Allergic Reactions [see Warnings and Precautions (5.7) ] Autoimmunity [see Warnings and Precautions (5.9) ] Immunosuppression [see Warnings and Precautions (5.10) ] Most common adverse reactions (incidence > 5%): infections and injection site reactions. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Amgen Inc. at 1-800-77-AMGEN (1-800-772-6436) or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Across clinical studies and postmarketing experience, the most serious adverse reactions with Enbrel were infections, neurologic events, CHF, and hematologic events [see Warnings and Precautions (5) ] . The most common adverse reactions with Enbrel were infections and injection site reactions. Because clinical trials are conducted under widely varying conditions, adverse reactions 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 predict the rates observed in clinical practice. Adverse Reactions in Adult Patients with Rheumatoid Arthritis, Psoriatic Arthritis, Ankylosing Spondylitis, or Plaque Psoriasis The data described below reflect exposure to Enbrel in 2219 adult patients with RA followed for up to 80 months, in 182 patients with PsA for up to 24 months, in 138 patients with AS for up to 6 months, and in 1204 adult patients with PsO for up to 18 months. In controlled trials, the proportion of Enbrel-treated patients who discontinued treatment due to adverse events was approximately 4% in the indications studied. Adverse Reactions in Pediatric Patients In general, the adverse reactions in pediatric patients were similar in frequency and type as those seen in adult patients [see Warnings and Precautions (5) , Use in Specific Populations (8.4) , and Clinical Studies (14.2 , 14.6) ] . In a 48-week clinical study in 211 children aged 4 to 17 years with pediatric PsO, the adverse reactions reported were similar to those seen in previous studies in adults with PsO. Long-term safety profile for up to 264 additional weeks was assessed in an open-label extension study and no new safety signals were identified. In open-label clinical studies of children with JIA, adverse reactions reported in those ages 2 to 4 years were similar to adverse reactions reported in older children. Infections Infections, including viral, bacterial, and fungal infections, have been observed in adult and pediatric patients. Infections have been noted in all body systems and have been reported in patients receiving Enbrel alone or in combination with other immunosuppressive agents. In controlled portions of trials, the types and severity of infection were similar between Enbrel and the respective control group (placebo or MTX for RA and PsA patients) in RA, PsA, AS and PsO patients. Rates of infections in RA and adult PsO patients are provided in Table 3 and Table 4, respectively. Infections consisted primarily of upper respiratory tract infection, sinusitis and influenza. In controlled portions of trials in RA, PsA, AS and PsO, the rates of serious infection were similar (0.8% in placebo, 3.6% in MTX, and 1.4% in Enbrel/Enbrel + MTX-treated groups). In clinical trials in rheumatologic indications, serious infections experienced by patients have included, but are not limited to, pneumonia, cellulitis, septic arthritis, bronchitis, gastroenteritis, pyelonephritis, sepsis, abscess and osteomyelitis. In clinical trials in adult PsO patients, serious infections experienced by patients have included, but are not limited to, pneumonia, cellulitis, gastroenteritis, abscess and osteomyelitis. The rate of serious infections was not increased in open-label extension trials and was similar to that observed in Enbrel- and placebo-treated patients from controlled trials. In 66 global clinical trials of 17,505 patients (21,015 patient-years of therapy), tuberculosis was observed in approximately 0.02% of patients. In 17,696 patients (27,169 patient-years of therapy) from 38 clinical trials and 4 cohort studies in the U.S. and Canada, tuberculosis was observed in approximately 0.006% of patients. These studies include reports of pulmonary and extrapulmonary tuberculosis [see Warnings and Precautions (5.1) ] . The types of infections reported in pediatric patients with PsO and JIA were generally mild and consistent with those commonly seen in the general pediatric population. Two JIA patients developed varicella infection and signs and symptoms of aseptic meningitis,

7 DRUG INTERACTIONS Specific drug interaction studies have not been conducted with Enbrel. Live vaccines – Avoid concurrent administration with Enbrel ( 5.8 , 7.1 ) Anakinra – Increased risk of serious infection ( 5.12 , 7.2 ) Abatacept – Increased risk of serious adverse events, including infections ( 5.12 , 7.2 ) Cyclophosphamide – Not recommended for use with Enbrel. ( 7.3 ) 7.1 Vaccines Most PsA patients receiving Enbrel were able to mount effective B-cell immune responses to pneumococcal polysaccharide vaccine, but titers in aggregate were moderately lower and fewer patients had 2-fold rises in titers compared to patients not receiving Enbrel. The clinical significance of this is unknown. Patients receiving Enbrel may receive concurrent vaccinations, except for live vaccines. No data are available on the secondary transmission of infection by live vaccines in patients receiving Enbrel. Patients with a significant exposure to varicella virus should temporarily discontinue Enbrel therapy and be considered for prophylactic treatment with varicella zoster immune globulin [see Warnings and Precautions (5.8 , 5.10) ] . 7.2 Immune-Modulating Biologic Products In a study in which patients with active RA were treated for up to 24 weeks with concurrent Enbrel and anakinra therapy, a 7% rate of serious infections was observed, which was higher than that observed with Enbrel alone (0%) [see Warnings and Precautions (5.12) ] and did not result in higher ACR response rates compared to Enbrel alone. The most common infections consisted of bacterial pneumonia (4 cases) and cellulitis (4 cases). One patient with pulmonary fibrosis and pneumonia died due to respiratory failure. Two percent of patients treated concurrently with Enbrel and anakinra developed neutropenia (ANC < 1 × 10 9 /L). In clinical studies, concurrent administration of abatacept and Enbrel resulted in increased incidences of serious adverse events, including infections, and did not demonstrate increased clinical benefit [see Warnings and Precautions (5.12) ] . 7.3 Cyclophosphamide The use of Enbrel in patients receiving concurrent cyclophosphamide therapy is not recommended [see Warnings and Precautions (5.11) ] . 7.4 Sulfasalazine Patients in a clinical study who were on established therapy with sulfasalazine, to which Enbrel was added, were noted to develop a mild decrease in mean neutrophil counts in comparison to groups treated with either Enbrel or sulfasalazine alone. The clinical significance of this observation is unknown.