CASODEX (Page 2 of 5)

6.2. Postmarketing Experience

The following adverse reactions have been identified during postapproval use of CASODEX. 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.

Uncommon cases of hypersensitivity reactions, including angioneurotic edema and urticaria have been seen [see Contraindications (4.1) ]. Cases of interstitial lung disease (some fatal), including interstitial pneumonitis and pulmonary fibrosis, have been reported with CASODEX. Interstitial lung disease has been reported most often at doses greater than 50 mg. A few cases of fatal hepatic failure have been reported.

Reduction in glucose tolerance, manifesting as diabetes or a loss of glycemic control in those with pre-existing diabetes, has been reported during treatment with LHRH agonists.

7. DRUG INTERACTIONS

Clinical studies have not shown any drug interactions between bicalutamide and LHRH analogs (goserelin or leuprolide). There is no evidence that bicalutamide induces hepatic enzymes.

In vitro studies have shown that R-bicalutamide is an inhibitor of CYP 3A4 with lesser inhibitory effects on CYP 2C9, 2C19 and 2D6 activity. Clinical studies have shown that with co-administration of CASODEX, mean midazolam (a CYP 3A4 substrate) levels may be increased 1.5 fold (for Cmax ) and 1.9 fold (for AUC). Hence, caution should be exercised when CASODEX is co-administered with CYP 3A4 substrates.

In vitro protein-binding studies have shown that bicalutamide can displace coumarin anticoagulants from binding sites. Prothrombin times should be closely monitored in patients already receiving coumarin anticoagulants who are started on CASODEX and adjustment of the anticoagulant dose may be necessary.

8. USE IN SPECIFIC POPULATIONS

8.1. Pregnancy

PREGNANCY CATEGORY X [see Contraindications (4.3)]. Based on its mechanism of action, CASODEX may cause fetal harm when administered to a pregnant woman. CASODEX is contraindicated in women, including those who are or may become pregnant. If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to a fetus.

While there are no human data on the use of CASODEX in pregnancy and CASODEX is not for use in women, it is important to know that maternal use of an androgen receptor inhibitor could affect development of the fetus.

In animal reproduction studies, male offspring of rats receiving doses of 10 mg/kg/day (approximately 2/3 of clinical exposure at the recommended dose) and above, were observed to have reduced anogenital distance and hypospadias. These pharmacological effects have been observed with other antiandrogens. No other teratogenic effects were observed in rabbits receiving doses up to 200 mg/kg/day (approximately 1/3 of clinical exposure at the recommended dose) or rats receiving doses up to 250 mg/kg/day (approximately 2 times the clinical exposure at the recommended dose).

8.3. Nursing Mothers

CASODEX is not indicated for use in women.

8.4. Pediatric Use

The safety and effectiveness of CASODEX in pediatric patients have not been established.

CASODEX (bicalutamide) orodispersible tablet was studied in combination with ARIMIDEX (anastrozole) orodispersible tablet in an open-label, non-comparative, multi-center study that assessed the efficacy and safety of this combination regimen over 12 months in the treatment of gonadotropin-independent precocious puberty in boys with familial male-limited precocious puberty, also known as testotoxicosis. Patients were enrolled in the study if they had a baseline age ≥ 2 years and a diagnosis of testotoxicosis based on clinical features of progressive precocious puberty, symmetrical testicular enlargement, advanced bone age, pubertal levels of serum testosterone, prepubertal pattern of gonadotropin secretion following a GnRH stimulation test, and absence of other clinical and biochemical causes of testosterone excess. Thirteen out of the 14 patients enrolled completed 12 months of combination treatment (one patient was lost to follow-up). If central precocious puberty (CPP) developed an LHRH analog was to be added. Four patients were diagnosed with CPP during the 12-month study and received LHRH analog treatment and 2 additional patients were diagnosed at the end of the 12 months and received treatment subsequently. Mean ± SD characteristics at baseline were as follows: chronological age: 3.9±1.9 years; bone age 8.8±2.5; bone age/chronological age ratio: 2.06 ± 0.51; growth rate (cm/yr): 10.81 ± 4.22; growth rate standard deviation score (SDS): 0.41 ± 1.36.

The starting CASODEX dose was 12.5 mg. CASODEX was titrated in each patient until steady-state R-bicalutamide (the active isomer of bicalutamide) trough plasma concentration reached 5-15 mcg/mL, which is the range of therapeutic concentrations achieved in adults with prostate cancer following the administration of the currently approved CASODEX dose of 50 mg. The starting daily dose of anastrozole was 0.5 mg. Anastrozole was independently titrated in each patient until it reached at steady-state a serum estradiol concentration of <10 pmol/L (2.7 pg/mL). The following ascending doses were used for CASODEX: 12.5 mg, 25 mg, 50 mg, and 100 mg. For anastrozole there were two ascending doses: 0.5 mg and 1 mg. At the end of the titration phase 1 patient was on 12.5 mg CASODEX, 8 patients were on 50 mg CASODEX, and 4 patients were on 100 mg CASODEX; 10 patients were on 0.5 mg anastrozole and 3 patients were on 1 mg anastrozole. In the majority of patients, steady-state trough concentrations of R-bicalutamide appeared to be attained by Day 21 with once daily dosing. Steady-state trough plasma anastrozole concentrations appeared to be attained by Day 8.

The primary efficacy analysis of the study was to assess the change in growth rate after 12 months of treatment, relative to the growth rate during the ≥6 months prior to entering the study. Pre-study growth rates were obtained retrospectively. There was no statistical evidence that the growth rate was reduced during treatment. During CASODEX/ARIMIDEX treatment the mean growth rate (cm/yr) decreased by 1.6 cm/year, 95% CI (-4.7 to 1.5) p=0.28; the mean growth rate SDS decreased by 0.1 SD, 95% CI (–1.2 to 1.0) p=0.88. Table 2 shows descriptive data for growth rates for the overall population and for subgroups defined by history of previous treatment for testotoxicosis with ketoconazole, spironolactone, anastrozole or other aromatase inhibitors.

Table 2. Growth rates
*
PT = Previous treatment for testotoxicosis with ketoconazole, spironolactone, anastrazole or other aromatase inhibitors
Median calculated as midpoint of 3rd and 4th ranked observations
NPT = no previous treatment for testotoxicosis with ketoconazole, spironolactone, anastrozole or other aromatase inhibitors

Endpoint

Analysis population

Pre-study Mean

Change from pre-study to 12 months

% patients with growth reduction

Mean

Median

(Min, Max)

Growth rate (cm/yr)

All treated (n=13)

10.8

-1.6

-2.8

(-7.4, 8.4)

9/13 (69%)

PT * (n=6)

10.3

-0.2

-2.6

(-7.2, 8.4)

4/6 (67%)

NPT (n=7)

11.2

-2.8

-2.8

(-7.4, 1.1)

5/7 (71%)

Growth rate (SD units)

All treated (n=13)

0.4

-0.1

-0.4

(-2.7, 3.5)

9/13 (69%)

PT * (n=6)

-0.1

+0.7

-0.2

(-1.6, 3.5)

4/6 (67%)

NPT (n=7)

0.8

-0.7

-0.4

(-2.7, 0.5)

5/7 (71%)

Total testosterone concentrations increased by a mean of 5 mmol/L over the 12 months of treatment from a baseline mean of 10 mmol/L. Estradiol concentrations were at or below the level of quantification (9.81 pmol/L) for 11 of 12 patients after 12 months of treatment. Six of the 12 patients started treatment at an estradiol concentration below the level of quantification.

There were no deaths, serious adverse events, or discontinuations due to adverse events during the study. Of the 14 patients exposed to study treatment, 13 (92.9%) experienced at least one adverse event. The most frequently reported (>3 patients) adverse events were gynecomastia (7/14, 50%), central precocious puberty (6/14, 43%), vomiting (5/14, 36%), headache (3/14, 21%), pyrexia (3/14, 21%) and upper respiratory tract infection (3/14, 21%). Adverse reactions considered possibly related to bicalutamide by investigators included gynecomastia (6/14, 43%), central precocious puberty (2/14, 14%), breast tenderness (2/14, 14%), breast pain (1/14, 7%), asthenia (1/14, 7%), increased alanine aminotransferase [ALT] (1/14, 7%), increased aspartate aminotransferase [AST] (1/14, 7%), and musculoskeletal chest pain (1/14, 7%). Headache was the only adverse reaction considered possibly related to anastrazole by investigators. For the patient who developed elevated ALT and AST, the elevation was <3X ULN, and returned to normal without stopping treatment; there was no concomitant elevation in total bilirubin.

All MedLibrary.org resources are included in as near-original form as possible, meaning that the information from the original provider has been rendered here with only typographical or stylistic modifications and not with any substantive alterations of content, meaning or intent.

This site is provided for educational and informational purposes only, in accordance with our Terms of Use, and is not intended as a substitute for the advice of a medical doctor, nurse, nurse practitioner or other qualified health professional.

Privacy Policy | Copyright © 2024. All Rights Reserved.