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Reviewed by Arefa Cassoobhoy, MD, MPH
They say the research could lead to better treatment, because doctors would be able to know which tumors are more likely to grow and spread."...
Use In Pregnancy
Pregnancy Category X
Women who are or may become pregnant should not take FIRMAGON [see CONTRAINDICATIONS and Use In Specific Populations].
Hypersensitivity reactions, including anaphylaxis, urticaria and angioedema, have been reported postmarketing with Firmagon. In case of a serious hypersensitivity reaction, discontinue Firmagon immediately if the injection has not been completed, and manage as clinically indicated. Patients with a known history of serious hypersensitivity reactions to Firmagon should not be re-challenged with Firmagon.
Effect On QT/QTc Interval
Androgen deprivation therapy may prolong the QT interval. Providers should consider whether the benefits of androgen deprivation therapy outweigh the potential risks in patients with congenital long QT syndrome, congestive heart failure, frequent electrolyte abnormalities, and in patients taking drugs known to prolong the QT interval. Electrolyte abnormalities should be corrected. Consider periodic monitoring of electrocardiograms and electrolytes.
In the randomized, active-controlled trial comparing FIRMAGON to leuprolide, periodic electrocardiograms were performed. Seven patients, three ( < 1%) in the pooled degarelix group and four (2%) patients in the leuprolide 7.5 mg group, had a QTcF ≥ 500 msec. From baseline to end of study, the median change for FIRMAGON was 12.3 msec and for leuprolide was 16.7 msec.
Therapy with FIRMAGON results in suppression of the pituitary gonadal system. Results of diagnostic tests of the pituitary gonadotropic and gonadal functions conducted during and after FIRMAGON may be affected. The therapeutic effect of FIRMAGON should be monitored by measuring serum concentrations of prostate-specific antigen (PSA) periodically. If PSA increases, serum concentrations of testosterone should be measured.
Patient Counseling Information
Advise the patient to read the FDA-approved patient labeling (PATIENT INFORMATION).
- Patients should be informed of the possible side effects of androgen deprivation therapy, including hot flashes, flushing of the skin, increased weight, decreased sex drive, and difficulties with erectile function. Possible side effects related to therapy with FIRMAGON include redness, swelling, and itching at the injection site; these are usually mild, self limiting, and decrease within three days.
Carcinogenesis, Mutagenesis, Impairment Of Fertility
Degarelix was administered subcutaneously to rats every 2 weeks for 2 years at doses of 2, 10 and 25 mg/kg (about 9, 45 and 120% of the recommended human loading dose on a mg/m² basis). Long term treatment with degarelix at 25 mg/kg caused an increase in the combined incidence of benign hemangiomas plus malignant hemangiosarcomas in females.
Degarelix was administered subcutaneously to mice every 2 weeks for 2 years at doses of 2, 10 and 50 mg/kg (about 5, 22 and 120% of the recommended human loading dose (240 mg) on a mg/m² basis). There was no statistically significant increase in tumor incidence associated with this treatment.
Degarelix did not cause genetic damage in standard in vitro assays (bacterial mutation, human lymphocyte chromosome aberration) nor in in vivo rodent bone marrow micronucleus tests.
Single degarelix doses of ≥ 1 mg/kg (about 5% of the clinical loading dose on a mg/m² basis) caused reversible infertility in male rats. Single doses of ≥ 0.1 mg/kg (about 0.5% of the clinical loading dose on a mg/m² basis) caused a decrease in fertility in female rats.
Use In Specific Populations
Category X [see CONTRAINDICATIONS and WARNINGS AND PRECAUTIONS]
Women who are or may become pregnant should not take FIRMAGON.
When degarelix was given to rabbits during early organogenesis at doses of 0.002 mg/kg/day (about 0.02% of the clinical loading dose on a mg/m² basis), there was an increase in early post-implantation loss. Degarelix given to rabbits during mid and late organogenesis at doses of 0.006 mg/kg/day (about 0.05% of the clinical loading dose on a mg/m² basis) caused embryo/fetal lethality and abortion. When degarelix was given to female rats during early organogenesis, at doses of 0.0045 mg/kg/day (about 0.036% of the clinical loading dose on a mg/m² basis), there was an increase in early post-implantation loss. When degarelix was given to female rats during mid and late organogenesis, at doses of 0.045 mg/kg/day (about 0.36% of the clinical loading dose on a mg/m² basis), there was an increase in the number of minor skeletal abnormalities and variants.
FIRMAGON is not indicated for use in women and is contraindicated in women who are or who may become pregnant. It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants from degarelix, a decision should be made whether to discontinue nursing or discontinue the drug taking into account the importance of the drug to the mother.
Safety and effectiveness in pediatric patients have not been established.
Of the total number of subjects in clinical studies of FIRMAGON, 82% were age 65 and over, while 42% were age 75 and over. No overall differences in safety or effectiveness were observed between these subjects and younger subjects, but greater sensitivity of some older individuals cannot be ruled out.
No pharmacokinetic studies in renally impaired patients have been conducted. At least 20-30% of a given dose of degarelix is excreted unchanged in the urine.
A population pharmacokinetic analysis of data from the randomized study demonstrated that there is no significant effect of mild renal impairment [creatinine clearance (CrCL) 50-80 mL/min] on either the degarelix concentration or testosterone concentration. Data on patients with moderate or severe renal impairment is limited and therefore degarelix should be used with caution in patients with CrCL < 50 mL/min.
Patients with hepatic impairment were excluded from the randomized trial.
A single dose of 1 mg degarelix administered as an intravenous infusion over 1 hour was studied in 16 nonprostate cancer patients with either mild (Child Pugh A) or moderate (Child Pugh B) hepatic impairment. Compared to non-prostate cancer patients with normal liver function, the exposure of degarelix decreased by 10% and 18% in patients with mild and moderate hepatic impairment, respectively. Therefore, dose adjustment is not necessary in patients with mild or moderate hepatic impairment. However, since hepatic impairment can lower degarelix exposure, it is recommended that in patients with hepatic impairment testosterone concentrations should be monitored on a monthly basis until medical castration is achieved. Once medical castration is achieved, an every-other-month testosterone monitoring approach could be considered.
Patients with severe hepatic dysfunction have not been studied and caution is therefore warranted in this group.This monograph has been modified to include the generic and brand name in many instances.
Last reviewed on RxList: 1/25/2016
Additional Firmagon Information
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