Xtandi enzalutamide 40 mg Tablet, 120-count

5 WARNINGS AND PRECAUTIONS • Seizure occurred in 0.6% of patients receiving XTANDI. In patients with predisposing factors, seizures were reported in 2.2% of patients. Permanently discontinue XTANDI in patients who develop a seizure during treatment.

( 5.1 ) • Posterior reversible encephalopathy syndrome (PRES): Discontinue XTANDI. ( 5.2 ) • Hypersensitivity: Discontinue XTANDI. ( 5.3 ) • Ischemic Heart Disease: Optimize management of cardiovascular risk factors.

Discontinue XTANDI for Grade 3-4 adverse reactions ( 5.4 ) • Falls and Fractures: Evaluate patients for fracture and fall risk, and treat patients with bone-targeted agents according to established guidelines. ( 5.5 ) • Embryo-Fetal Toxicity: XTANDI can cause fetal harm and loss of pregnancy. Advise males with female partners of reproductive potential to use effective contraception.

( 5.6 , 8.1 , 8.3 ) • Severe Dysphagia or Choking Related to Product Size: Consider using smaller XTANDI tablet(s) in patients who have difficulty swallowing. Discontinue XTANDI for patients who cannot swallow capsules or tablets. ( 2.1 , 5.7 ) • Interference with Immunoassay Measurement of Digoxin: XTANDI can interfere with certain digoxin immunoassays, resulting in falsely elevated digoxin plasma concentration results.

( 5.8 , 7.3 )

5.1Seizure Seizure occurred in 0.6% of patients receiving XTANDI in eight randomized clinical trials. In these trials, patients with predisposing factors for seizure were generally excluded. Seizure occurred from 13 to 2250 days after initiation of XTANDI.

Patients experiencing seizure were permanently discontinued from therapy, and all seizure events resolved. In a single-arm trial designed to assess the risk of seizure in patients with pre-disposing factors for seizure, 8 of 366 (2.2%) XTANDI-treated patients experienced a seizure. Three of the 8 patients experienced a second seizure during continued treatment with XTANDI after their first seizure resolved.

It is unknown whether anti-epileptic medications will prevent seizures with XTANDI. Patients in the study had one or more of the following pre-disposing factors: the use of medications that may lower the seizure threshold (~ 54%), history of traumatic brain or head injury (~ 28%), history of cerebrovascular accident or transient ischemic attack (~ 24%), and Alzheimer’s disease, meningioma, or leptomeningeal disease from prostate cancer, unexplained loss of consciousness within the last 12 months, past history of seizure, presence of a space occupying lesion of the brain, history of arteriovenous malformation, or history of brain infection (all < 5%).

Approximately 17% of patients had more than one risk factor. Advise patients of the risk of developing a seizure while receiving XTANDI and of engaging in any activity where sudden loss of consciousness could cause serious harm to themselves or others. Permanently discontinue XTANDI in patients who develop a seizure during treatment.

5.2Posterior Reversible Encephalopathy Syndrome (PRES) There have been reports of posterior reversible encephalopathy syndrome (PRES) in patients receiving XTANDI [see Adverse Reactions ( 6.2 )] . PRES is a neurological disorder which can present with rapidly evolving symptoms including seizure, headache, lethargy, confusion, blindness, and other visual and neurological disturbances, with or without associated hypertension. A diagnosis of PRES requires confirmation by brain imaging, preferably magnetic resonance imaging (MRI).

Discontinue XTANDI in patients who develop PRES.

5.3Hypersensitivity Hypersensitivity reactions, including edema of the face (0.5%), tongue (0.1%), or lip (0.1%) have been observed with enzalutamide in eight randomized clinical trials. Pharyngeal edema has been reported in post-marketing cases. Advise patients who experience any symptoms of hypersensitivity to temporarily discontinue XTANDI and promptly seek medical care. Permanently discontinue XTANDI for serious hypersensitivity reactions.

5.4 Ischemic…

6 ADVERSE REACTIONS The following adverse reactions are discussed in more detail in other sections of the labeling: • Seizure [see Warnings and Precautions ( 5.1 )] • Posterior Reversible Encephalopathy Syndrome (PRES) [see Warnings and Precautions ( 5.2 )] • Hypersensitivity [see Warnings and Precautions ( 5.3 )] • Ischemic Heart Disease [see Warnings and Precautions ( 5.4 )] • Falls and Fractures [see Warnings and Precautions ( 5.5 )] • Dysphagia or Choking [see Warnings and Precautions ( 5.7 )] The most common adverse reactions (≥ 10%) that occurred more frequently (≥ 2% over placebo) in the XTANDI-treated patients are musculoskeletal pain, fatigue, hot flush, constipation, decreased appetite, diarrhea, hypertension, hemorrhage, fall, fracture, and headache.

( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Astellas Pharma US, Inc. at 1-800-727-7003 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch .

6.1Clinical 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. The data in WARNINGS and PRECAUTIONS reflect eight randomized, controlled trials [AFFIRM, PREVAIL, TERRAIN, PROSPER, ARCHES, EMBARK, Asian PREVAIL (NCT02294461), and STRIVE (NCT01664923)] that were pooled to conduct safety analyses in patients with CRPC (N = 3651), mCSPC (N = 754), or nmCSPC with high‑risk BCR (N = 707) treated with XTANDI.

Patients received XTANDI 160 mg (N = 5112) or placebo orally once daily (N = 2829) or bicalutamide 50 mg orally once daily (N = 387). In these eight trials, the median duration of treatment was 22.1 months (range: < 0.1 to 95.0) in patients that received XTANDI. In five placebo-controlled trials (AFFIRM, PROSPER, PREVAIL, ARCHES, and EMBARK), the median duration of treatment was 19.4 months (range: < 0.1 to 90.4) in the XTANDI group [see Clinical Studies ( 14 )].

In these five trials, the most common adverse reactions (≥ 10%) that occurred more frequently (≥ 2% over placebo) in the XTANDI-treated patients were musculoskeletal pain, fatigue, hot flush, constipation, decreased appetite, diarrhea, hypertension, hemorrhage, fall, fracture and headache. AFFIRM: XTANDI versus Placebo in Metastatic CRPC Following Chemotherapy AFFIRM enrolled 1199 patients with metastatic CRPC who had previously received docetaxel. The median duration of treatment was 8.3 months with XTANDI and 3.0 months with placebo.

During the trial, 48% of patients on the XTANDI arm and 46% of patients on the placebo arm received glucocorticoids. Grade 3 and higher adverse reactions were reported among 47% of XTANDI-treated patients. Discontinuations due to adverse reactions were reported for 16% of XTANDI-treated patients.

The most common adverse reaction leading to treatment discontinuation was seizure, which occurred in 0.9% of the XTANDI-treated patients compared to none (0%) of the placebo-treated patients. Table 1 shows adverse reactions reported in AFFIRM that occurred at a ≥ 2% higher frequency in the XTANDI arm compared to the placebo arm. Table 1.

Adverse Reactions in AFFIRM XTANDI (N = 800) Placebo (N = 399) Grade 1-4 CTCAE v 4. (%) Grade 3-4 (%) Grade 1-4 (%) Grade 3-4 (%) General Disorders Asthenic Conditions Includes asthenia and fatigue. 51 9 44 9 Peripheral Edema 15 1 13

0.8Musculoskeletal and Connective Tissue Disorders Back Pain 26 5 24 4 Arthralgia 21 2.5 17

1.8Musculoskeletal Pain 15 1.3 12

0.3Muscular Weakness 10 1.5 7

1.8Musculoskeletal Stiffness 2.6 0.3 0.3 0 Gastrointestinal Disorders Diarrhea 22 1.1 18

0.3Vascular Disorders Hot Flush 20 0 10 0 Hypertension 6 2.1 2.8

1.3Nervous System Disorders Headache 12 0.9 5 0 Dizziness Includes dizziness and vertigo. 9 0.5 7

0.5Spinal Cord Compression and Cauda Equina Syndrome 7 7 4.5

3.8Paresthesia 7 0 4.5 0 Mental Impairment Disorders Includes amnesia, memory impai…

7 DRUG INTERACTIONS • Strong CYP2C8 Inhibitors: Avoid strong CYP2C8 inhibitors. If coadministration cannot be avoided, reduce the dosage of XTANDI. ( 2.3 , 7.1 ) • Strong CYP3A4 Inducers: Avoid strong CYP3A4 inducers.

If coadministration cannot be avoided, increase the dosage of XTANDI. ( 2.3 , 7.1 ) • Avoid coadministration with certain CYP3A4, CYP2C9, or CYP2C19 substrates for which a minimal decrease in concentration may lead to therapeutic failure of the substrate. In cases where active metabolites are formed, there may be increased exposure to the active metabolites.

( 7.2 )

7.1Effect of Other Drugs on XTANDI Strong CYP2C8 Inhibitors The coadministration of XTANDI with gemfibrozil (a strong CYP2C8 inhibitor) increases plasma concentrations of enzalutamide plus N-desmethyl enzalutamide, which may increase the incidence and severity of adverse reactions of XTANDI. Avoid the coadministration of XTANDI with strong CYP2C8 inhibitors. If the coadministration of XTANDI with a strong CYP2C8 inhibitor cannot be avoided, reduce the dosage of XTANDI [see Dosage and Administration ( 2.3 ), Clinical Pharmacology ( 12.3 )].

Strong CYP3A4 Inducers The coadministration of XTANDI with rifampin (a strong CYP3A4 inducer and a moderate CYP2C8 inducer) decreases plasma concentrations of enzalutamide plus N-desmethyl enzalutamide, which may decrease the efficacy of XTANDI. Avoid the coadministration of XTANDI with strong CYP3A4 inducers. If the coadministration of XTANDI with a strong CYP3A4 inducer cannot be avoided, increase the dosage of XTANDI [see Dosage and Administration ( 2.3 ), Clinical Pharmacology ( 12.3 )].

7.2Effect of XTANDI on Other Drugs Certain CYP3A4, CYP2C9, or CYP2C19 Substrates XTANDI is a strong CYP3A4 inducer and a moderate CYP2C9 and CYP2C19 inducer. The coadministration of XTANDI decreases the concentrations of certain CYP3A4, CYP2C9, or CYP2C19 substrates [see Clinical Pharmacology ( 12.3 )] , which may reduce the efficacy of these substrates. Avoid the coadministration of XTANDI with certain CYP3A4, CYP2C9, or CYP2C19 substrates for which a minimal decrease in concentration may lead to therapeutic failure of the substrate.

If the coadministration cannot be avoided, increase the dosage of these substrates in accordance with their Prescribing Information. In cases where active metabolites are formed, there may be increased exposure to the active metabolites.

7.3Laboratory Test Interference XTANDI can interfere with certain digoxin immunoassays (e.g., Chemiluminescent Microparticle Immunoassays), resulting in falsely elevated digoxin plasma concentration results. Notify the laboratory conducting the digoxin plasma concentration assay to use an appropriate method in patients receiving XTANDI and digoxin [see Warnings and Precautions ( 5.8 )] .