Abiraterone

5 WARNINGS AND PRECAUTIONS Mineralocorticoid excess: Closely monitor patients with cardiovascular disease. Control hypertension and correct hypokalemia before treatment. Monitor blood pressure, serum potassium and symptoms of fluid retention at least monthly. (5.1) Adrenocortical insufficiency: Monitor for symptoms and signs of adrenocortical insufficiency. Increased dosage of corticosteroids may be indicated before, during and after stressful situations. (5.2) Hepatotoxicity: Can be severe and fatal. Monitor liver function and modify, interrupt, or discontinue abiraterone acetate dosing as recommended. (5.3) Increased fractures and mortality in combination with radium Ra 223 dichloride: Use of abiraterone acetate plus prednisone/prednisolone in combination with radium Ra 223 dichloride is not recommended. (5.4) Embryo-Fetal Toxicity: Abiraterone acetate can cause fetal harm. Advise males with female partners of reproductive potential to use effective contraception. (5.5, 8.1, 8.3) Hypoglycemia: Severe hypoglycemia has been reported in patients with pre-existing diabetes who are taking medications containing thiazolidinediones (including pioglitazone) or repaglinide. Monitor blood glucose in patients with diabetes and assess if antidiabetic agent dose modifications are required. (5.6) 5.1 Hypokalemia, Fluid Retention, and Cardiovascular Adverse Reactions due to Mineralocorticoid Excess Abiraterone acetate may cause hypertension, hypokalemia, and fluid retention as a consequence of increased mineralocorticoid levels resulting from CYP17 inhibition [see Clinical Pharmacology (12.1) ] . Monitor patients for hypertension, hypokalemia, and fluid retention at least once a month. Control hypertension and correct hypokalemia before and during treatment with abiraterone acetate. In the combined data from 4 placebo-controlled trials using prednisone 5 mg twice daily in combination with 1,000 mg abiraterone acetate daily, grades 3 to 4 hypokalemia were detected in 4% of patients on the abiraterone acetate arm and 2% of patients on the placebo arm. Grades 3 to 4 hypertension were observed in 2% of patients each arm and grades 3 to 4 fluid retention in 1% of patients each arm. In LATITUDE (a randomized placebo-controlled, multicenter clinical trial), which used prednisone 5 mg daily in combination with 1,000 mg abiraterone acetate daily, grades 3 to 4 hypokalemia were detected in 10% of patients on the abiraterone acetate arm and 1% of patients on the placebo arm, grades 3 to 4 hypertension were observed in 20% of patients on the abiraterone acetate arm and 10% of patients on the placebo arm. Grades 3 to 4 fluid retention occurred in 1% of patients each arm [see Adverse Reactions (6) ] . Closely monitor patients whose underlying medical conditions might be compromised by increases in blood pressure, hypokalemia or fluid retention, such as those with heart failure, recent myocardial infarction, cardiovascular disease, or ventricular arrhythmia. In postmarketing experience, QT prolongation and Torsades de Pointes have been observed in patients who develop hypokalemia while taking abiraterone acetate. The safety of abiraterone acetate in patients with left ventricular ejection fraction <50% or New York Heart Association (NYHA) Class III or IV heart failure (in COU-AA-301) or NYHA Class II to IV heart failure (in COU-AA-302 and LATITUDE) has not been established because these patients were excluded from these randomized clinical trials [see Clinical Studies (14) ] . 5.2 Adrenocortical Insufficiency Adrenal insufficiency occurred in 0.3% of 2,230 patients taking abiraterone acetate and in 0.1% of 1,763 patients taking placebo in the combined data of the 5 randomized, placebo-controlled clinical studies. Adrenocortical insufficiency was reported in patients receiving abiraterone acetate in combination with prednisone, following interruption of daily steroids and/or with concurrent infection or stress. Monitor patients for symptoms and signs of adrenocortical insufficiency, particularly if patients are withdrawn from prednisone, have prednisone dose reductions, or experience unusual stress. Symptoms and signs of adrenocortical insufficiency may be masked by adverse reactions associated with mineralocorticoid excess seen in patients treated with abiraterone acetate. If clinically indicated, perform appropriate tests to confirm the diagnosis of adrenocortical insufficiency. Increased dosage of corticosteroids may be indicated before, during and after stressful situations [see Warnings and Precautions (5.1) ] . 5.3 Hepatotoxicity In postmarketing experience, there have been abiraterone acetate-associated severe hepatic toxicity, including fulminant hepatitis, acute liver failure and deaths [see Adverse Reactions (6.2) ] . In the combined data of 5 randomized clinical trials, grade 3 to 4 ALT or AST increases (at least 5 x ULN) were reported in 6% of 2,230 patients who received abiraterone acetate, typically during the first 3 months after starting treatment. Patients whose baseline ALT or AST were elevated were more likely to experience liver test elevation than those beginning with normal values. Treatment discontinuation due to ALT and AST increases or abnormal hepatic function occurred in 1.1% of 2,230 patients taking abiraterone acetate. In these clinical trials, no deaths clearly related to abiraterone acetate were reported due to hepatotoxicity events. Measure serum transaminases (ALT and AST) and bilirubin levels prior to starting treatment with abiraterone acetate, every two weeks for the first three months of treatment and monthly thereafter. In patients with baseline moderate hepatic impairment receiving a reduced abiraterone acetate dose of 250 mg, measure ALT, AST, and bilirubin prior to the start of treatment, every week for the first month, every two weeks for the following two months of treatment and monthly thereafter. Promptly measure serum total bilirubin, AST, and ALT if clinical symptoms or signs suggestive of hepatotoxicity develop. Elevations of AST, ALT, or bilirubin from the patient’s baseline should prompt more frequent monitoring. If at any time AST or ALT rise above five times the ULN, or the bilirubin rises above three times the ULN, interrupt abiraterone acetate treatment and closely monitor liver function. Re-treatment with abiraterone acetate at a reduced dose level may take place only after return of liver function tests to the patient’s baseline or to AST and ALT less than or equal to 2.5 x ULN and total bilirubin less than or equal to 1.5 x ULN [see Dosage and Administration (2.4) ] . Permanently discontinue abiraterone acetate for patients who develop a concurrent elevation of ALT greater than 3 x ULN and total bilirubin greater than 2 x ULN in the absence of biliary obstruction or other causes responsible for the concurrent elevation [see Dosage and Administration (2.4) ] . The safety of abiraterone acetate re-treatment of patients who develop AST or ALT greater than or equal to 20 x ULN and/or bilirubin greater than or equal to 10 x ULN is unknown. 5.4 Increased Fractures and Mortality in Combination with Radium Ra 223 Dichloride Abiraterone acetate plus prednisone/prednisolone is not recommended for use in combination with radium Ra 223 dichloride outside of clinical trials. The clinical efficacy and safety of concurrent initiation of abiraterone acetate plus prednisone/prednisolone and radium Ra 223 dichloride was assessed in a randomized, placebo-controlled multicenter study (ERA-223 trial) in 806 patients with asymptomatic or mildly symptomatic castration-resistant prostate cancer with bone metastases. The study was unblinded early based on an Independent Data Monitoring Committee recommendation. At the primary analysis, increased incidences of fractures (28.6% vs 11.4%) and deaths (38.5% vs 35.5%) have been observed in patients who received abiraterone acetate plus prednisone/prednisolone in combination with radium Ra 223 dichloride compared to patients who received placebo in combination with abiraterone acetate plus prednisone/prednisolone. 5.5 Embryo-Fetal Toxicity The safety and efficacy of abiraterone acetate have not been established in females. Based on animal reproductive studies and mechanism of action, abiraterone acetate can cause fetal harm and loss of pregnancy when administered to a pregnant female. In animal reproduction studies, oral administration of abiraterone acetate to pregnant rats during organogenesis caused adverse developmental effects at maternal exposures approximately ≥ 0.03 times the human exposure (AUC) at the recommended dose. Advise males with female partners of reproductive potential to use effective contraception during treatment with abiraterone acetate and for 3 weeks after the last dose of abiraterone acetate [see Use in Specific Populations (8.1 , 8.3) ] . Abiraterone acetate should not be handled by females who are or may become pregnant [see How Supplied/Storage and Handling (16) ] . 5.6 Hypoglycemia Severe hypoglycemia has been reported when abiraterone acetate was administered to patients with pre-existing diabetes receiving medications containing thiazolidinediones (including pioglitazone) or repaglinide [see Drug Interactions (7.2) ] . Monitor blood glucose in patients with diabetes during and after discontinuation of treatment with abiraterone acetate. Assess if antidiabetic drug dosage needs to be adjusted to minimize the risk of hypoglycemia.

6 ADVERSE REACTIONS The following are discussed in more detail in other sections of the labeling: Hypokalemia, Fluid Retention, and Cardiovascular Adverse Reactions due to Mineralocorticoid Excess [see Warnings and Precautions (5.1) ] . Adrenocortical Insufficiency [see Warnings and Precautions (5.2) ] . Hepatotoxicity [see Warnings and Precautions (5.3) ] . Increased Fractures and Mortality in Combination with Radium Ra 223 Dichloride [see Warnings and Precautions (5.4) ] . The most common adverse reactions (≥10%) are fatigue, arthralgia, hypertension, nausea, edema, hypokalemia, hot flush, diarrhea, vomiting, upper respiratory infection, cough, and headache. (6.1) The most common laboratory abnormalities (>20%) are anemia, elevated alkaline phosphatase, hypertriglyceridemia, lymphopenia, hypercholesterolemia, hyperglycemia, and hypokalemia. (6.1) To report SUSPECTED ADVERSE REACTIONS, contact Amneal Pharmaceuticals at 1-877-835-5472 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 clinical practice. Two randomized placebo-controlled, multicenter clinical trials (COU-AA-301 and COU-AA-­302) enrolled patients who had metastatic CRPC in which abiraterone acetate was administered orally at a dose of 1,000 mg daily in combination with prednisone 5 mg twice daily in the active treatment arms. Placebo plus prednisone 5 mg twice daily was given to patients on the control arm. A third randomized placebo-controlled, multicenter clinical trial (LATITUDE) enrolled patients who had metastatic high-risk CSPC in which abiraterone acetate was administered at a dose of 1,000 mg daily in combination with prednisone 5 mg once daily. Placebos were administered to patients in the control arm. Additionally, two other randomized, placebo-controlled trials were conducted in patients with metastatic CRPC. The safety data pooled from 2,230 patients in the 5 randomized controlled trials constitute the basis for the data presented in the Warnings and Precautions, Grade 1 to 4 adverse reactions, and Grade 1 to 4 laboratory abnormalities. In all trials, a gonadotropin-releasing hormone (GnRH) analog or prior orchiectomy was required in both arms. In the pooled data, median treatment duration was 11 months (0.1, 43) for abiraterone acetate-treated patients and 7.2 months (0.1, 43) for placebo-treated patients. The most common adverse reactions (≥10%) that occurred more commonly (>2%) in the abiraterone acetate arm were fatigue, arthralgia, hypertension, nausea, edema, hypokalemia, hot flush, diarrhea, vomiting, upper respiratory infection, cough, and headache. The most common laboratory abnormalities (>20%) that occurred more commonly (≥2%) in the abiraterone acetate arm were anemia, elevated alkaline phosphatase, hypertriglyceridemia, lymphopenia, hypercholesterolemia, hyperglycemia, and hypokalemia. Grades 3 to 4 adverse events were reported for 53% of patients in the abiraterone acetate arm and 46% of patients in the placebo arm. Treatment discontinuation was reported in 14% of patients in the abiraterone acetate arm and 13% of patients in the placebo arm. The common adverse events (≥1%) resulting in discontinuation of abiraterone acetate and prednisone were hepatotoxicity and cardiac disorders. Deaths associated with treatment-emergent adverse events were reported for 7.5% of patients in the abiraterone acetate arm and 6.6% of patients in the placebo arm. Of the patients in the abiraterone acetate arm, the most common cause of death was disease progression (3.3%). Other reported causes of death in ≥5 patients included pneumonia, cardio-respiratory arrest, death (no additional information), and general physical health deterioration. COU-AA-301: Metastatic CRPC Following Chemotherapy COU-AA-301 enrolled 1195 patients with metastatic CRPC who had received prior docetaxel chemotherapy. Patients were not eligible if AST and/or ALT ≥2.5 x ULN in the absence of liver metastases. Patients with liver metastases were excluded if AST and/or ALT >5 x ULN. Table 1 shows adverse reactions on the abiraterone acetate arm in COU-AA-301 that occurred with a ≥2% absolute increase in frequency compared to placebo or were events of special interest. The median duration of treatment with abiraterone acetate with prednisone was 8 months. Table 1: Adverse Reactions due to Abiraterone Acetate in COU-AA-301 System/Organ Class Adverse reaction Abiraterone Acetate with Prednisone (N=791) Placebo with Prednisone (N=394) All Grades 1 % Grade 3 to 4 % All Grades % Grade 3 to 4 % Musculoskeletal and connective tissue disorders Joint swelling/discomfort 2 30 4.2 23 4.1 Muscle discomfort 3 26 3.0 23 2.3 General disorders Edema 4 27 1.9 18 0.8 Vascular disorders Hot flush 19 0.3 17 0.3 Hypertension 8.5 1.3 6.9 0.3 Gastrointestinal disorders Diarrhea 18 0.6 14 1.3 Dyspepsia 6.1 0 3.3 0 Infections and infestations Urinary tract infection 12 2.1 7.1 0.5 Upper respiratory tract infection 5.4 0 2.5 0 Respiratory, thoracic and mediastinal disorders Cough 11 0 7.6 0 Renal and urinary disorders Urinary frequency 7.2 0.3 5.1 0.3 Nocturia 6.2 0 4.1 0 Injury, poisoning and procedural complications Fractures 5 5.9 1.4 2.3 0 Cardiac disorders Arrhythmia 6 7.2 1.1 4.6 1.0 Chest pain or chest discomfort 7 3.8 0.5 2.8 0 Cardiac failure 8 2.3 1.9 1.0 0.3 1 Adverse events graded according to CTCAE version 3.0. 2 Includes terms Arthritis, Arthralgia, Joint swelling, and Joint stiffness. 3 Includes terms Muscle spasms, Musculoskeletal pain, Myalgia, Musculoskeletal discomfort, and Musculoskeletal stiffness. 4 Includes terms Edema, Edema peripheral, Pitting edema, and Generalized edema. 5 Includes all fractures with the exception of pathological fracture. 6 Includes terms Arrhythmia, Tachycardia, Atrial fibrillation, Supraventricular tachycardia, Atrial tachycardia, Ventricular tachycardia, Atrial flutter, Bradycardia, Atrioventricular block complete, Conduction disorder, and Bradyarrhythmia. 7 Includes terms Angina pectoris, Chest pain, and Angina unstable. Myocardial infarction or ischemia occurred more commonly in the placebo arm than in the abiraterone acetate arm (1.3% vs. 1.1% respectively). 8 Includes terms Cardiac failure, Cardiac failure congestive, Left ventricular dysfunction, Cardiogenic shock, Cardiomegaly, Cardiomyopathy, and Ejection fraction decreased. Table 2 shows laboratory abnormalities of interest from COU-AA-301. Table 2: Laboratory Abnormalities of Interest in COU-AA-301 Laboratory Abnormality Abiraterone Acetate with Prednisone (N=791) Placebo with Prednisone (N=394) All Grades (%) Grade 3 to 4 (%) All Grades (%) Grade 3 to 4 (%) Hypertriglyceridemia 63 0.4 53 0 High AST 31 2.1 36 1.5 Hypokalemia 28 5.3 20 1.0 Hypophosphatemia 24 7.2 16 5.8 High ALT 11 1.4 10 0.8 High Total Bilirubin 6.6 0.1 4.6 0 COU-AA-302: Metastatic CRPC Prior to Chemotherapy COU-AA-302 enrolled 1,088 patients with metastatic CRPC who had not received prior cytotoxic chemotherapy. Patients were ineligible if AST and/or ALT ≥2.5 x ULN and patients were excluded if they had liver metastases. Table 3 shows adverse reactions on the abiraterone acetate arm in COU-AA-302 that occurred in ≥5% of patients with a ≥2% absolute increase in frequency compared to placebo. The median duration of treatment with abiraterone acetate with prednisone was 13.8 months. Table 3: Adverse Reactions in ≥5% of Patients on the Abiraterone Acetate Arm in COU-AA-302 System/Organ Class Adverse reaction Abiraterone Acetate with Prednisone (N=542) Placebo with Prednisone (N=540) All Grades 1 % Grade 3 to 4 % All Grades % Grade 3 to 4 % General disorders Fatigue 39 2.2 34 1.7 Edema 2 25 0.4 21 1.1 Pyrexia 8.7 0.6 5.9 0.2 Musculoskeletal and connective tissue disorders Joint swelling/discomfort 3 30 2.0 25 2.0 Groin pain 6.6 0.4 4.1 0.7 Gastrointestinal disorders Constipation 23 0.4 19 0.6 Diarrhea 22 0.9 18 0.9 Dyspepsia 11 0.0 5.0 0.2 Vascular disorders Hot flush 22 0.2 18 0.0 Hypertension 22 3.9 13 3.0 Respiratory, thoracic and mediastinal disorders Cough 17 0.0 14 0.2 Dyspnea 12 2.4 9.6 0.9 Psychiatric disorders Insomnia 14 0.2 11 0.0 Injury, poisoning and procedural complications Contusion 13 0.0 9.1 0.0 Falls 5.9 0.0 3.3 0.0 Infections and infestations Upper respiratory tract infection 13 0.0 8.0 0.0 Nasopharyngitis 11 0.0 8.1 0.0 Renal and urinary disorders Hematuria 10 1.3 5.6 0.6 Skin and subcutaneous tissue disorders Rash 8.1 0.0 3.7 0.0 1 Adverse events graded according to CTCAE version 3.0. 2 Includes terms Edema peripheral, Pitting edema, and Generalized edema. 3 Includes terms Arthritis, Arthralgia, Joint swelling, and Joint stiffness. Table 4 shows laboratory abnormalities that occurred in greater than 15% of patients, and more frequently (>5%) in the abiraterone acetate arm compared to placebo in COU-AA-302. Table 4: Laboratory Abnormalities in >15% of Patients in the Abiraterone Acetate Arm of COU-AA-302 Laboratory Abnormality Abiraterone Acetate with Prednisone (N=542) Placebo with Prednisone (N=540) Grade 1 to 4 % Grade 3 to 4 % Grade 1 to 4 % Grade 3 to 4 % Hematology Lymphopenia 38 8.7 32 7.4 Chemistry Hyperglycemia 1 57 6.5 51 5.2 High ALT 42 6.1 29 0.7 High AST 37 3.1 29 1.1 Hypernatremia 33 0.4 25 0.2 Hypokalemia 17 2.8 10 1.7 1 Based on non-fasting blood draws LATITUDE: Patients with Metastatic High-risk CSPC LATITUDE enrolled 1,199 patients with newly-diagnosed metastatic, high-risk CSPC who had not received prior cytotoxic chemotherapy. Patients were ineligible if AST and/or ALT ≥2.5 x ULN or if they had liver metastases. All the patients received GnRH analogs or had prior bilateral orchiectomy during the trial. The median duration of treatment with abiraterone acetate tablets and prednisone was 24 months. Table 5 shows adverse reactions on the abiraterone acetate tablets arm that occurred in ≥5% of patients with a ≥2% absolute increase in frequency compared to those on the placebos arm. Table 5: Adverse Reactions in ≥ 5% of Patients on the Abiraterone Acetate Arm in LATITUDE 1 System/Organ Class Adverse reaction Abiraterone Acetate with Prednisone (N=597) Placebos (N=602) All Grades 2 % Grade 3 to 4 % All Grades % Grade 3 to 4 % Vascular disorders Hypertension 37 20 13 10 Hot flush 15 0.0 13 0.2 Metabolism and nutrition disorders Hypokalemia 20 10 3.7 1.3 Investigations Alanine aminotransferase increased 3 16 5.5 13 1.3 Aspartate aminotransferase increased 3 15 4.4 11 1.5 Infections and infestations Urinary tract infection 7.0 1.0 3.7 0.8 Upper respiratory tract infection 6.7 0.2 4.7 0.2 Nervous system disorders Headache 7.5 0.3 5.0 0.2 Respiratory, Thoracic and Mediastinal Disorders Cough 4 6.5 0.0 3.2 0 1 All patients were receiving an GnRH agonist or had undergone orchiectomy. 2 Adverse events graded according to CTCAE version 4.0 3 Reported as an adverse event or reaction 4 Including cough, productive cough, upper airway cough syndrome Table 6 shows laboratory abnormalities that occurred in >15% of patients, and more frequently (>5%) in the Abiraterone Acetate arm compared to placebos. Table 6: Laboratory Abnormalities in >15% of Patients in the Abiraterone Acetate Arm of LATITUDE Laboratory Abnormality Abiraterone Acetate with Prednisone (N=597) Placebos (N=602) Grade 1 to 4 % Grade 3 to 4 % Grade 1 to 4 % Grade 3 to 4 % Hematology Lymphopenia 20 4.1 14 1.8 Chemistry Hypokalemia 30 9.6 6.7 1.3 Elevated ALT 46 6.4 45 1.3 Elevated total bilirubin 16 0.2 6.2 0.2 Cardiovascular Adverse Reactions In the combined data of 5 randomized, placebo-controlled clinical studies, cardiac failure occurred more commonly in patients on the abiraterone acetate arm compared to patients on the placebo arm (2.6% versus 0.9%). Grade 3 to 4 cardiac failure occurred in 1.3% of patients taking abiraterone acetate and led to 5 treatment discontinuations and 4 deaths. Grade 3 to 4 cardiac failure occurred in 0.2% of patients taking placebo. There were no treatment discontinuations and two deaths due to cardiac failure in the placebo group. In the same combined data, the majority of arrhythmias were grade 1 or 2. There was one death associated with arrhythmia and three patients with sudden death in the abiraterone acetate arms and five deaths in the placebo arms. There were 7 (0.3%) deaths due to cardiorespiratory arrest in the abiraterone acetate arms and 2 (0.1%) deaths in the placebo arms. Myocardial ischemia or myocardial infarction led to death in 3 patients in the placebo arms and 3 deaths in the abiraterone acetate arms. 6.2 Postmarketing Experience The following additional adverse reactions have been identified during post approval use of abiraterone acetate with prednisone. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Respiratory, Thoracic and Mediastinal Disorders: non-infectious pneumonitis. Musculoskeletal and Connective Tissue Disorders: myopathy, including rhabdomyolysis. Hepatobiliary Disorders: fulminant hepatitis, including acute hepatic failure and death. Cardiac Disorders: QT prolongation and Torsades de Pointes (observed in patients who developed hypokalemia or had underlying cardiovascular conditions). Immune System Disorders: Hypersensitivity: anaphylactic reactions (severe allergic reactions that include, but are not limited to difficulty swallowing or breathing, swollen face, lips, tongue or throat, or an itchy rash (urticaria)).

7 DRUG INTERACTIONS CYP3A4 Inducers: Avoid concomitant strong CYP3A4 inducers during abiraterone acetate tablets treatment. If a strong CYP3A4 inducer must be co-administered, increase the abiraterone acetate tablets dosing frequency. (2.5, 7.1) CYP2D6 Substrates: Avoid co-administration of abiraterone acetate tablets with CYP2D6 substrates that have a narrow therapeutic index. If an alternative treatment cannot be used, exercise caution and consider a dose reduction of the concomitant CYP2D6 substrate. (7.2) 7.1 Drugs that Inhibit or Induce CYP3A4 Enzymes Based on in vitro data, abiraterone acetate is a substrate of CYP3A4. In a dedicated drug interaction trial, co-administration of rifampin, a strong CYP3A4 inducer, decreased exposure of abiraterone by 55%. Avoid concomitant strong CYP3A4 inducers during abiraterone acetate treatment. If a strong CYP3A4 inducer must be co-administered, increase the abiraterone acetate dosing frequency [see Dosage and Administration (2.5) and Clinical Pharmacology (12.3) ] . In a dedicated drug interaction trial, co-administration of ketoconazole, a strong inhibitor of CYP3A4, had no clinically meaningful effect on the pharmacokinetics of abiraterone [see Clinical Pharmacology (12.3) ] . 7.2 Effects of Abiraterone on Drug Metabolizing Enzymes Abiraterone acetate is an inhibitor of the hepatic drug-metabolizing enzymes CYP2D6 and CYP2C8. In a CYP2D6 drug-drug interaction trial, the C max and AUC of dextromethorphan (CYP2D6 substrate) were increased 2.8- and 2.9-fold, respectively, when dextromethorphan was given with abiraterone acetate 1,000 mg daily and prednisone 5 mg twice daily. Avoid co-administration of abiraterone acetate with substrates of CYP2D6 with a narrow therapeutic index (e.g., thioridazine). If alternative treatments cannot be used, consider a dose reduction of the concomitant CYP2D6 substrate drug [see Clinical Pharmacology (12.3) ] . In a CYP2C8 drug-drug interaction trial in healthy subjects, the AUC of pioglitazone (CYP2C8 substrate) was increased by 46% when pioglitazone was given together with a single dose of 1,000 mg abiraterone acetate. Therefore, patients should be monitored closely for signs of toxicity related to a CYP2C8 substrate with a narrow therapeutic index if used concomitantly with abiraterone acetate [see Clinical Pharmacology (12.3) and Warnings and Precautions (5.6) ] .

8 USE IN SPECIFIC POPULATIONS Do not use abiraterone acetate tablets in patients with baseline severe hepatic impairment (Child-Pugh Class C). (8.6) 8.1 Pregnancy Risk Summary The safety and efficacy of abiraterone acetate have not been established in females. Based on findings from animal studies and the mechanism of action, abiraterone acetate can cause fetal harm and potential loss of pregnancy. There are no human data on the use of abiraterone acetate in pregnant women. In animal reproduction studies, oral administration of abiraterone acetate to pregnant rats during organogenesis caused adverse developmental effects at maternal exposures approximately ≥ 0.03 times the human exposure (AUC) at the recommended dose (see Data ) . Data Animal Data In an embryo-fetal developmental toxicity study in rats, abiraterone acetate caused developmental toxicity when administered at oral doses of 10, 30 or 100 mg/kg/day throughout the period of organogenesis (gestational days 6 to 17). Findings included embryo-fetal lethality (increased post implantation loss and resorptions and decreased number of live fetuses), fetal developmental delay (skeletal effects) and urogenital effects (bilateral ureter dilation) at doses ≥10 mg/kg/day, decreased fetal ano-genital distance at ≥30 mg/kg/day, and decreased fetal body weight at 100 mg/kg/day. Doses ≥10 mg/kg/day caused maternal toxicity. The doses tested in rats resulted in systemic exposures (AUC) approximately 0.03, 0.1 and 0.3 times, respectively, the AUC in patients. 8.2 Lactation Risk Summary The safety and efficacy of abiraterone acetate have not been established in females. There is no information available on the presence of abiraterone in human milk, or on the effects on the breastfed child or milk production. 8.3 Females and Males of Reproductive Potential Contraception Males Based on findings in animal reproduction studies and its mechanism of action, advise males with female partners of reproductive potential to use effective contraception during treatment and for 3 weeks after the final dose of abiraterone acetate [see Use in Specific Populations (8.1) ] . Infertility Based on animal studies, abiraterone acetate may impair reproductive function and fertility in males of reproductive potential [see Nonclinical Toxicology (13.1) ] . 8.4 Pediatric Use Safety and effectiveness of abiraterone acetate in pediatric patients have not been established. 8.5 Geriatric Use Of the total number of patients receiving abiraterone acetate in randomized clinical trials, 70% of patients were 65 years and over and 27% were 75 years and over. No overall differences in safety or effectiveness were observed between these elderly patients and younger patients. Other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out. 8.6 Patients with Hepatic Impairment The pharmacokinetics of abiraterone were examined in subjects with baseline mild (N=8) or moderate (N=8) hepatic impairment (Child-Pugh Class A and B, respectively) and in 8 healthy control subjects with normal hepatic function. The systemic exposure (AUC) of abiraterone after a single oral 1,000 mg dose of abiraterone acetate increased by approximately 1.1-fold and 3.6-fold in subjects with mild and moderate baseline hepatic impairment, respectively compared to subjects with normal hepatic function. In another trial, the pharmacokinetics of abiraterone were examined in subjects with baseline severe (N=8) hepatic impairment (Child-Pugh Class C) and in 8 healthy control subjects with normal hepatic function. The systemic exposure (AUC) of abiraterone increased by approximately 7-fold and the fraction of free drug increased 2-fold in subjects with severe baseline hepatic impairment compared to subjects with normal hepatic function. No dosage adjustment is necessary for patients with baseline mild hepatic impairment. In patients with baseline moderate hepatic impairment (Child-Pugh Class B), reduce the recommended dose of abiraterone acetate to 250 mg once daily. Do not use abiraterone acetate in patients with baseline severe hepatic impairment (Child-Pugh Class C). If elevations in ALT or AST >5 x ULN or total bilirubin >3 x ULN occur in patients with baseline moderate hepatic impairment, discontinue abiraterone acetate treatment [see Dosage and Administration (2.4) and Clinical Pharmacology (12.3) ] . For patients who develop hepatotoxicity during treatment, interruption of treatment and dosage adjustment may be required [see Dosage and Administration (2.4) , Warnings and Precautions (5.3) , and Clinical Pharmacology (12.3) ] . 8.7 Patients with Renal Impairment No dosage adjustment is necessary for patients with renal impairment [see Clinical Pharmacology (12.3) ] .