abiraterone acetate

RECENT MAJOR CHANGES SECTION Dosage and Administration, Important Administration Instructions (2.3) 08/2021 Warnings and Precautions, Hypoglycemia (5.6) 10/2020

1 INDICATIONS AND USAGE Abiraterone acetate tablets are indicated in combination with prednisone for the treatment of patients with • Metastatic castration-resistant prostate cancer (CRPC) • Metastatic high-risk castration-sensitive prostate cancer (CSPC) Abiraterone acetate tablets are a CYP17 inhibitor indicated in combination with prednisone for the treatment of patients with • metastatic castration-resistant prostate cancer (CRPC). ( 1 ) • metastatic high-risk castration-sensitive prostate cancer (CSPC). ( 1 )

2 DOSAGE AND ADMINISTRATION ­ Metastatic castration-resistant prostate cancer: • Abiraterone acetate tablets 1,000 mg orally once daily with prednisone 5 mg orally twice daily. ( 2.1 ) Metastatic castration-sensitive prostate cancer: • Abiraterone acetate tablets 1,000 mg orally once daily with prednisone 5 mg orally once daily. ( 2.2 ) Patients receiving abiraterone acetate tablets should also receive a gonadotropin-releasing hormone (GnRH) analog concurrently or should have had bilateral orchiectomy. Abiraterone acetate tablets must be taken as a single dose once daily on an empty stomach. Do not eat food 2 hours before and 1 hour after taking abiraterone acetate tablets. The tablets must be swallowed whole with water. Do not crush or chew tablets.( 2.3) Dose Modification: • For patients with baseline moderate hepatic impairment (Child-Pugh Class B), reduce the abiraterone acetate tablets starting dose to 250 mg once daily. ( 2.4 ) • For patients who develop hepatotoxicity during treatment, hold abiraterone acetate tablets until recovery. Retreatment may be initiated at a reduced dose. Abiraterone acetate tablets should be discontinued if patients develop severe hepatotoxicity. ( 2.4 ) 2.1 Recommended Dose for Metastatic CRPC The recommended dose of abiraterone acetate tablets is 1,000 mg (two 500 mg tablets or four 250 mg tablets) orally once daily with prednisone 5 mg orally twice daily. 2.2 Recommended Dose for Metastatic High-risk CSPC The recommended dose of abiraterone acetate tablets is 1,000 mg (two 500 mg tablets or four 250 mg tablets) orally once daily with prednisone 5 mg administered orally once daily. 2.3 Important Administration Instructions Patients receiving abiraterone acetate tablets should also receive a gonadotropin-releasing hormone (GnRH) analog concurrently or should have had bilateral orchiectomy. Abiraterone acetate tablets must be taken as a single dose once daily on an empty stomach. Do not eat food 2 hours before and 1 hour after taking abiraterone acetate tablets. The tablets must be swallowed whole with water. Do not crush or chew tablets. 2.4 Dose Modification Guidelines in Hepatic Impairment and Hepatotoxicity Hepatic Impairment In patients with baseline moderate hepatic impairment (Child-Pugh Class B), reduce the recommended dose of abiraterone acetate tablets to 250 mg once daily. In patients with moderate hepatic impairment monitor 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. If elevations in ALT and/or AST greater than 5 x upper limit of normal (ULN) or total bilirubin greater than 3 x ULN occur in patients with baseline moderate hepatic impairment, discontinue abiraterone acetate tablets and do not re-treat patients with abiraterone acetate tablets [see Use in Specific Populations ( 8.6 ) and Clinical Pharmacology ( 12.3 )]. Do not use abiraterone acetate tablets in patients with baseline severe hepatic impairment (Child-Pugh Class C). Hepatotoxicity For patients who develop hepatotoxicity during treatment with abiraterone acetate tablets (ALT and/or AST greater than 5 x ULN or total bilirubin greater than 3 x ULN), interrupt treatment with abiraterone acetate tablets [see Warnings and Precautions ( 5.3 )]. Treatment may be restarted at a reduced dose of 750 mg once daily following 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. For patients who resume treatment, monitor serum transaminases and bilirubin at a minimum of every two weeks for three months and monthly thereafter. If hepatotoxicity recurs at the dose of 750 mg once daily, re-treatment may be restarted at a reduced dose of 500 mg once daily following 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 …

3 DOSAGE FORMS AND STRENGTHS Abiraterone acetate tablets USP, 250 mg are white to off-white, oval shaped, film coated tablets debossed with "35" on one side and plain on other side. Abiraterone acetate tablets USP, 500 mg are pinkish brown color, oval shaped, biconvex, film coated tablets, debossed with "46" on one side and plain other side and free from physical defects. Film-Coated Tablets: 250 mg and 500 mg (3)

4 CONTRAINDICATIONS Pregnancy Abiraterone acetate can cause fetal harm and potential loss of pregnancy [see Use in Specific Populations (8.1) ]. Pregnancy. (4, 8.1)

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 C …

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 Females and Males of Reproductive Potential: Advise males with female partners of reproductive potential to use effective contraception. (8.3) Do not use abiraterone acetate tablets in patients with baseline severe hepatic impairment (Child-Pugh Class C). (8.6) 8.1 Pregnancy Risk Summary Based on findings from animal studies and the mechanism of action, abiraterone acetate is contraindicated for use in pregnant women because the drug can cause fetal harm and potential loss of pregnancy. Abiraterone acetate is not indicated for use in females. 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 Abiraterone acetate is not indicated for use in women. There is no information available on the presence of abiraterone acetate 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 impairm …

12.1 Mechanism of Action Abiraterone acetate is converted in vivo to abiraterone, an androgen biosynthesis inhibitor, that inhibits 17 α-hydroxylase/C17,20-lyase (CYP17). This enzyme is expressed in testicular, adrenal, and prostatic tumor tissues and is required for androgen biosynthesis. CYP17 catalyzes two sequential reactions: 1) the conversion of pregnenolone and progesterone to their 17α-hydroxy derivatives by 17α-hydroxylase activity and 2) the subsequent formation of dehydroepiandrosterone (DHEA) and androstenedione, respectively, by C17,20-lyase activity. DHEA and androstenedione are androgens and are precursors of testosterone. Inhibition of CYP17 by abiraterone can also result in increased mineralocorticoid production by the adrenals [see Warnings and Precautions ( 5.1 )] . Androgen sensitive prostatic carcinoma responds to treatment that decreases androgen levels. Androgen deprivation therapies, such as treatment with GnRH agonists or orchiectomy, decrease androgen production in the testes but do not affect androgen production by the adrenals or in the tumor. Abiraterone acetate decreased serum testosterone and other androgens in patients in the placebo-controlled clinical trial. It is not necessary to monitor the effect of Abiraterone Acetate on serum testosterone levels. Changes in serum prostate specific antigen (PSA) levels may be observed but have not been shown to correlate with clinical benefit in individual patients.

11 DESCRIPTION Abiraterone acetate, USP the active ingredient of Abiraterone Acetate Tablets, USP is the acetyl ester of abiraterone. Abiraterone is an inhibitor of CYP17 (17α-hydroxylase/C17,20-lyase). Each Abiraterone acetate tablet contains either 250 mg or 500 mg of abiraterone acetate, USP. Abiraterone acetate is designated chemically as (3β)-17-(3-pyridinyl) androsta-5,16-dien-3-yl acetate and its structure is: Abiraterone acetate, USP is a white or almost white, non-hygroscopic, solid powder and freely soluble in methylene chloride, tetrahydrofuran, and toluene, soluble in methanol, ethanol, ethyl acetate, isobutyl methyl ketone, N,N-dimethylformamide, and acetone, sparingly soluble in acetonitrile and dimethyl sulfoxide, slightly soluble in hexane, very slightly soluble in 0.1 N hydrochloric acid and practically insoluble aqueous media over a wide range of pH values. Its molecular formula is C 26 H 33 NO 2 and it has a molecular weight of 391.6 g/mol. Abiraterone Acetate Tablets, USP are available in 500 mg film-coated tablets and 250 mg uncoated tablets with the following inactive ingredients: • 500 mg film-coated tablets: colloidal silicon dioxide, croscarmellose sodium, lactose monohydrate, magnesium stearate, microcrystalline cellulose, povidone K–30 and sodium lauryl sulfate. The coating, Opadry II 85F500121 Purple, contains iron oxide black, iron oxide red, polyethylene glycol, polyvinyl alcohol-part hydrolyzed, talc, and titanium dioxide. • 250 mg uncoated tablets: colloidal silicon dioxide, croscarmellose sodium, lactose monohydrate, magnesium stearate, microcrystalline cellulose, povidone and sodium lauryl sulfate. FDA approved dissolution test specifications differ from USP. Structure.jpg

10 OVERDOSAGE Human experience of overdose with abiraterone acetate is limited. There is no specific antidote. In the event of an overdose, stop abiraterone acetate, undertake general supportive measures, including monitoring for arrhythmias and cardiac failure and assess liver function.

16 HOW SUPPLIED/STORAGE AND HANDLING Abiraterone acetate tablets USP, 250 mg are white to off-white, oval shaped, film coated tablets debossed with “35” on one side and plain on other side. Abiraterone acetate tablets USP, 250 mg are available in high-density polyethylene bottles of 120 tablets and also available in unit dose package of 30 (3 x 10) tablets. Bottles of 120 NDC 75907-224-04 Unit dose package of 30 (3 x 10) NDC 75907-224-31 Abiraterone acetate tablets USP, 500 mg are pinkish brown color, oval shaped, biconvex, film coated tablets, debossed with "46" on one side and plain other side and free from physical defects. Abiraterone acetate tablets USP, 500 mg are available in high-density polyethylene bottles of 60 tablets and unit dose package of 60 (6 x 10) tablets. Bottles of 60 NDC 75907-226-60 Unit dose package of 60 (6 x 10) NDC 75907-226-38. Storage and Handling Store at 20°C to 25°C (68°F to 77°F); excursions permitted in the range from 15°C to 30°C (59°F to 86°F) [see USP Controlled Room Temperature]. Keep out of reach of children. Based on its mechanism of action, abiraterone acetate may harm a developing fetus. Women who are pregnant or women who may be pregnant should not handle abiraterone acetate 250 mg tablets if broken, crushed, or damaged without protection, e.g., gloves [see Use in Specific Populations ( 8.1 )].