Warnings for Gleostine
Included as part of the "PRECAUTIONS" Section
Precautions for Gleostine
Delayed Myelosuppression
Gleostine causes myelosuppression that can result in fatal infections and bleeding. Myelosuppression from Gleostine is delayed, dose-related, and cumulative. It usually occurs 4 to 6 weeks after drug administration and persists for 1 to 2 weeks. Thrombocytopenia is generally more severe than leukopenia. Cumulative myelosuppression from Gleostine is manifested by greater severity and longer duration of cytopenias.
Monitor blood counts for at least 6 weeks after each dose. Do not give Gleostine more frequently than every 6 weeks. Adjust dose based on nadir blood counts from prior dose [see DOSAGE AND ADMINISTRATION].
Risk Of Overdosage
Fatal toxicity occurs with overdosage of Gleostine. Dispensing or administering more than one dose can lead to fatal toxicity.
Prescribe only one dose at a time. Dispense only enough capsules for one dose. Both physician and pharmacist should emphasize to the patient that only one dose of Gleostine is taken every 6 weeks [see DOSAGE AND ADMINISTRATION and OVERDOSE].
Pulmonary Toxicity
Pulmonary toxicity characterized by pulmonary infiltrates and/or fibrosis occurs with Gleostine. Patients with a baseline below 70% of the predicted Forced Vital Capacity (FVC) or Carbon Monoxide Diffusing Capacity (DL ) are at increased risk. The onset of pulmonary toxicity occurs after an interval of 6 months or longer from the start of therapy, with cumulative doses of Gleostine usually greater than 1100 mg/m2 .
Obtain baseline pulmonary function tests prior to initiating treatment and repeat frequently during treatment. Permanently discontinue Gleostine in patients diagnosed with pulmonary fibrosis.
Secondary Malignancies
Secondary malignancies, including acute leukemia and myelodysplasia, occur with long term use.
Hepatotoxicity
Hepatic toxicity, manifested by increased levels of transaminases, alkaline phosphatase, and bilirubin occurs with Gleostine.
Monitor liver function.
Nephrotoxicity
Progressive renal failure with a decrease in kidney size occurs with Gleostine.
Monitor renal function.
Embryo-Fetal Toxicity
Based on animal data and its mechanism of action, Gleostine can cause fetal harm when administered to a pregnant woman. Embryo-fetal toxicity and teratogenicity occurred in rats and rabbits receiving lomustine daily during organogenesis at doses approximately two to four times the total human dose of 130 mg/m2 over 6 weeks (0.18 to 0.27 times the single human dose of 130 mg/m2 ) based on body surface area (BSA). Advise pregnant women of the potential risk to a fetus. Advise females of reproductive potential to use effective contraception during treatment with Gleostine and for 2 weeks after the final dose. Advise males with female partners of reproductive potential to use effective contraception during treatment with Gleostine and for 3.5 months after the final dose [see Use In Specific Populations] .
Nonclinical Toxicology
Carcinogenesis, Mutagenesis, Impairment Of Fertility
Lomustine is carcinogenic in rats and mice, producing a marked increase in tumor incidence in doses lower than those employed clinically.
In female rats, daily intraperitoneal treatment with lomustine for 2 weeks prior to mating with untreated males resulted in dose dependent decreases in number of corpora lutea and resorption rates with no live births at a dose of 3 mg/kg (approximately 0.14 times the recommended clinical dose of 130 mg/m2 based on body surface area (BSA), or approximately twice the total clinical dose of lomustine over 6 weeks) and decreased pup survival during the first 4 postnatal days at doses greater than or equal to 1.5 mg/kg (a daily dose of approximately 0.06 times the recommended clinical dose of 130 mg/m2 based on BSA or approximately equal to the total clinical dose of lomustine over 6 weeks). Gleostine may also result in decreased male fertility. Intraperitoneal injection of lomustine resulted in decreased fertility in male rats mated to untreated females based on decreased implantations and decreased fetal body weight at weekly doses greater than or equal to 5 mg/kg (approximately 0.23 times the single clinical dose of 130 mg/m2 based on BSA, or approximately equal to the total clinical dose of lomustine over 6 weeks), and increased resorptions at doses greater than or equal to 2.5 mg/kg/week.
Use In Specific Populations
Pregnancy
Risk Summary
Based on animal data and its mechanism of action, Gleostine can cause fetal harm when administered to a pregnant woman [see CLINICAL PHARMACOLOGY] . There are no available data on Gleostine exposure in pregnant women. Lomustine was teratogenic in rats and embryotoxic in rabbits at total dose levels approximately two to four times the total human dose of 130 mg/m2 over 6 weeks (0.18 to 0.27 times the single human dose of 130 mg/m2 ) based on BSA [see Data]. Advise pregnant women of the potential risk to a fetus.
In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively.
Data
Animal Data
Lomustine was administered by intraperitoneal injection daily to pregnant rats during the period of organogenesis at dose levels of 0, 2, 4, 6, and 8 mg/kg. Resorption rates and post-implantation loss occurred at doses greater than or equal to 4 mg/kg (approximately 0.18 times the clinical dose of 130 mg/m2 based on BSA or approximately twice the total clinical dose of lomustine over 6 weeks). Malformations (omphalocele, ectopia cordis, scoliosis, syndactyly, hydrocephalus, microphthalmia, anophthalmia, anomalies of aortic arch, dextrocardia, malpositioning of the ovaries and testes, sternoschisis, and shortened/misshapen bone of the fore or hind limbs) and decreased fetal body weight occurred at all dose levels. In pregnant rabbits treated with lomustine at 3 mg/kg (approximately 0.27 times the 130 mg/m2 clinical dose based on BSA or approximately four times the total clinical dose of lomustine over 6 weeks) during organogenesis, there were increases in abortions and decreases in surviving pup weight that persisted postnatally.
Lactation
Risk Summary
There is no information on the presence of lomustine or its metabolites in human milk, its effects on the breastfed infant, or its effects on milk production. Because of the potential for serious adverse reactions in breastfed infants from Gleostine, advise women not to breastfeed during treatment with Gleostine and for 2 weeks after the final dose.
Females And Males Of Reproductive Potential
Contraception
Females
Based on animal data and its mechanism of action, Gleostine can cause fetal harm [see Pregnancy] . Advise females of reproductive potential to use effective contraception during treatment and for 2 weeks after the final dose.
Males
Based on Gleostine's mechanism of action, advise males with female partners of reproductive potential to use effective contraception during treatment with Gleostine and for 3.5 months after the final dose [see CLINICAL PHARMACOLOGY] .
Infertility
Based on animal findings and its mechanism of action, Gleostine may result in reduced fertility in males and females of reproductive potential [see Nonclinical Toxicology] .
Pediatric Use
Pediatric use, including dose, is not based on adequate and well-controlled clinical studies.
Geriatric Use
No data in the clinical studies of Gleostine are available for patients 65 years of age and over to determine whether they respond differently than younger patients. Other reported clinical experience has not identified differences in responses between elderly and younger patients. In general, dose selection for an elderly patient should be cautious, reflecting the greater frequency of decreased hepatic, renal, or cardiac function and of concomitant disease or other drug therapy.
Lomustine and its metabolites are known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and renal function should be monitored.