8 USE IN SPECIFIC POPULATIONS
There are no adequate and well-controlled clinical studies in pregnant women, therefore the potential risk to the fetus with the use of filgrastim products is unknown. Reports in the scientific literature have described transplacental passage of filgrastim in pregnant women when administered ≤ 30 hours prior to preterm delivery (≤ 30 weeks gestation). In animal reproduction studies, effects of filgrastim on prenatal development have been studied in rats and rabbits. No malformations were observed in either species. No maternal or fetal effects were observed in pregnant rats at doses up to 58 times the human doses. Filgrastim been shown to have adverse effects in pregnant rabbits at doses 2 to 10 times higher than the human doses (see Data).
The estimated background risk of major birth defects and miscarriage for the indicated populations is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. 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.
Several observational studies based on the Severe Chronic Neutropenia International Registry (SCNIR) described pregnancy outcomes in women with severe chronic neutropenia (SCN) who were exposed to filgrastim products during pregnancy and women with SCN who were unexposed. No major differences were seen between treated and untreated women with respect to pregnancy outcome (including miscarriage and preterm labor), newborn complications (including birth weight) and infections. Methodological limitations of these studies, include small sample size, and lack of generalizability due to the underlying maternal condition.
Effects of filgrastim on prenatal development have been studied in rats and rabbits. No malformations were observed in either species. Filgrastim has been shown to have adverse effects in pregnant rabbits at doses 2 to 10 times higher than the human doses. In pregnant rabbits showing signs of maternal toxicity, reduced embryo-fetal survival (at 20 and 80 mcg/kg/day) and increased abortions (at 80 mcg/kg/day) were observed. In pregnant rats, no maternal or fetal effects were observed at doses up to 575 mcg/kg/day, which is approximately 58 times higher than the human dose of 10 mcg/kg/day.
Offspring of rats administered filgrastim during the peri-natal and lactation periods exhibited a delay in external differentiation and growth retardation (≥ 20 mcg/kg/day) and slightly reduced survival rate (100 mcg/kg/day).
There is published literature documenting transfer of filgrastim products into human milk. There are a few case reports describing the use of filgrastim products in breastfeeding mothers with no adverse effects noted in the infants. There are no data on the effects of filgrastim products on milk production. Other recombinant filgrastim products are secreted poorly into breast milk, and filgrastim products are not absorbed orally by neonates. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for NIVESTYM and any potential adverse effects on the breastfed child from NIVESTYM or from the underlying maternal condition.
8.4 Pediatric Use
NIVESTYM prefilled syringe with BD UltraSafe Plus™ Passive Needle Guard may not accurately measure volumes less than 0.3 mL due to the needle spring mechanism design. Therefore, the direct administration of a volume less than 0.3 mL using NIVESTYM prefilled syringe is not recommended due to the potential for dosing errors. For direct administration of doses less than 0.3 mL (180 mcg) use NIVESTYM single-dose vial.
In patients with cancer receiving myelosuppressive chemotherapy‚ 15 pediatric patients median age 2.6 (range 1.2 to 9.4) years with neuroblastoma were treated with myelosuppressive chemotherapy (cyclophosphamide‚ cisplatin‚ doxorubicin‚ and etoposide) followed by subcutaneous filgrastim at doses of 5, 10, or 15 mcg/kg/day for 10 days (n = 5/dose) (Study 8). The pharmacokinetics of filgrastim in pediatric patients after chemotherapy were similar to those in adults receiving the same weight-normalized doses, suggesting no age-related differences in the pharmacokinetics of filgrastim. In this population‚ filgrastim was well-tolerated. There was one report of palpable splenomegaly and one report of hepatosplenomegaly associated with filgrastim therapy; however‚ the only consistently reported adverse event was musculoskeletal pain‚ which is no different from the experience in the adult population.
The safety and effectiveness of filgrastim have been established in pediatric patients with SCN [see Clinical Studies (14.5)]. In a phase 3 study (Study 7) to assess the safety and efficacy of filgrastim in the treatment of SCN, 123 patients with a median age of 12 years (range 7 months to 76 years) were studied. Of the 123 patients, 12 were infants (7 months to 2 years of age), 49 were children (2 to 12 years of age), and 9 were adolescents (12 to 16 years of age). Additional information is available from a SCN postmarketing surveillance study, which includes long-term follow-up of patients in the clinical studies and information from additional patients who entered directly into the postmarketing surveillance study. Of the 731 patients in the surveillance study, 429 were pediatric patients < 18 years of age (range 0.9 to 17) [see Indications and Usage (1.5), Dosage and Administration (2.5), and Clinical Studies (14.5)].
Long-term follow-up data from the postmarketing surveillance study suggest that height and weight are not adversely affected in patients who received up to 5 years of filgrastim treatment. Limited data from patients who were followed in the phase 3 study for 1.5 years did not suggest alterations in sexual maturation or endocrine function.
Pediatric patients with congenital types of neutropenia (Kostmann's syndrome, congenital agranulocytosis, or Schwachman-Diamond syndrome) have developed cytogenetic abnormalities and have undergone transformation to MDS and AML while receiving chronic filgrastim treatment. The relationship of these events to filgrastim administration is unknown [see Warnings and Precautions (5.8) and Adverse Reactions (6)].
8.5 Geriatric Use
Among 855 subjects enrolled in 3 randomized, placebo-controlled trials of filgrastim-treated patients receiving myelosuppressive chemotherapy, there were 232 subjects age 65 or older, and 22 subjects age 75 or older. No overall differences in safety or effectiveness were observed between these subjects and younger subjects.
Clinical studies of filgrastim in other approved indications (i.e., BMT recipients, PBPC mobilization, and SCN) did not include sufficient numbers of subjects aged 65 and older to determine whether elderly subjects respond differently from younger subjects.