GeneralSimultaneous Use With Chemotherapy
and Radiation TherapyThe safety and efficacy of NEUPOGEN® given
simultaneously with cytotoxic chemotherapy have not been established. Because of
the potential sensitivity of rapidly dividing myeloid cells to cytotoxic
chemotherapy‚ do not use NEUPOGEN® in the period 24 hours
before through 24 hours after the administration of cytotoxic chemotherapy (see
DOSAGE AND
ADMINISTRATION).
The efficacy of NEUPOGEN® has not been evaluated in
patients receiving chemotherapy associated with delayed myelosuppression (eg,
nitrosoureas) or with mitomycin C or with myelosuppressive doses of
antimetabolites such as 5-fluorouracil.
The safety and efficacy of NEUPOGEN® have not been
evaluated in patients receiving concurrent radiation therapy. Simultaneous use
of NEUPOGEN® with chemotherapy and radiation therapy
should be avoided.
Potential Effect on Malignant
CellsNEUPOGEN® is a growth factor that
primarily stimulates neutrophils. However‚ the possibility that NEUPOGEN® can act as a growth factor for any tumor type cannot be
excluded. In a randomized study evaluating the effects of NEUPOGEN® versus placebo in patients undergoing remission induction for
AML, there was no significant difference in remission rate, disease-free, or
overall survival (see CLINICAL
EXPERIENCE).
The safety of NEUPOGEN® in chronic myeloid leukemia
(CML) and myelodysplasia has not been established.
When NEUPOGEN® is used to mobilize PBPC‚ tumor cells
may be released from the marrow and subsequently collected in the leukapheresis
product. The effect of reinfusion of tumor cells has not been well studied‚ and
the limited data available are inconclusive.
LeukocytosisCancer Patients Receiving
Myelosuppressive ChemotherapyWhite blood cell counts of 100‚000/mm3 or
greater were observed in approximately 2% of patients receiving NEUPOGEN® at doses above 5 mcg/kg/day. There were no reports of adverse
events associated with this degree of leukocytosis. In order to avoid the
potential complications of excessive leukocytosis‚ a CBC is recommended twice
per week during NEUPOGEN® therapy (see LABORATORY
MONITORING).
Premature Discontinuation of
NEUPOGEN® TherapyCancer Patients Receiving
Myelosuppressive ChemotherapyA transient increase in neutrophil counts is typically seen 1 to
2 days after initiation of NEUPOGEN® therapy. However‚
for a sustained therapeutic response‚ NEUPOGEN® therapy
should be continued following chemotherapy until the post nadir ANC reaches
10‚000/mm3. Therefore‚ the premature discontinuation of
NEUPOGEN® therapy‚ prior to the time of recovery from the
expected neutrophil nadir‚ is generally not recommended (see DOSAGE AND
ADMINISTRATION).
ImmunogenicityAs with all therapeutic proteins, there is a potential for
immunogenicity. The incidence of antibody development in patients receiving
NEUPOGEN® has not been adequately determined. While
available data suggest that a small proportion of patients developed binding
antibodies to Filgrastim, the nature and specificity of these antibodies has not
been adequately studied. In clinical studies comparing NEUPOGEN® and Neulasta®, the incidence of
antibodies binding to NEUPOGEN® was 3% (11/333). In these
11 patients, no evidence of a neutralizing response was observed using a
cell-based bioassay. The detection of antibody formation is highly dependent on
the sensitivity and specificity of the assay, and the observed incidence of
antibody positivity in an assay may be influenced by several factors including
timing of sampling, sample handling, concomitant medications, and underlying
disease. Therefore, comparison of the incidence of antibodies to NEUPOGEN® with the incidence of antibodies to other products may be
misleading.
Cytopenias resulting from an antibody response to exogenous growth factors
have been reported on rare occasions in patients treated with other recombinant
growth factors. There is a theoretical possibility that an antibody directed
against Filgrastim may cross-react with endogenous G-CSF, resulting in
immune-mediated neutropenia; however, this has not been reported in clinical
studies or in post-marketing experience. Patients who develop hypersensitivity
to Filgrastim (NEUPOGEN®) may have allergic or
hypersensitivity reactions to other E coli-derived
proteins.
Cutaneous Vasculitis
Cutaneous vasculitis has been reported in patients treated with
NEUPOGEN®. In most cases‚ the severity of cutaneous
vasculitis was moderate or severe. Most of the reports involved patients with
SCN receiving long-term NEUPOGEN® therapy. Symptoms of
vasculitis generally developed simultaneously with an increase in the ANC and
abated when the ANC decreased. Many patients were able to continue NEUPOGEN® at a reduced dose.
Information for Patients and
CaregiversPatients should be referred to the “Information for Patients and
Caregivers” labeling included with the package insert in each dispensing pack of
NEUPOGEN® vials or NEUPOGEN®
prefilled syringes. The “Information for Patients and Caregivers” labeling
provides information about neutrophils and neutropenia and the safety and
efficacy of NEUPOGEN®. It is not intended to be a
disclosure of all known or possible effects.
Laboratory MonitoringCancer Patients Receiving
Myelosuppressive ChemotherapyA CBC and platelet count should be obtained prior to
chemotherapy‚ and at regular intervals (twice per week) during NEUPOGEN® therapy. Following cytotoxic chemotherapy‚ the neutrophil
nadir occurred earlier during cycles when NEUPOGEN® was
administered‚ and WBC differentials demonstrated a left shift‚ including the
appearance of promyelocytes and myeloblasts. In addition‚ the duration of severe
neutropenia was reduced‚ and was followed by an accelerated recovery in the
neutrophil counts.
Cancer Patients Receiving Bone
Marrow TransplantFrequent CBCs and platelet counts are recommended (at least 3
times per week) following marrow transplantation.
Patients With Severe Chronic
NeutropeniaDuring the initial 4 weeks of NEUPOGEN®
therapy and during the 2 weeks following any dose adjustment‚ a CBC with
differential and platelet count should be performed twice weekly. Once a patient
is clinically stable‚ a CBC with differential and platelet count should be
performed monthly during the first year of treatment. Thereafter, if clinically
stable, routine monitoring with regular CBCs (ie, as clinically indicated but at
least quarterly) is recommended. Additionally, for those patients with
congenital neutropenia, annual bone marrow and cytogenetic evaluations should be
performed throughout the duration of treatment (see WARNINGS,
ADVERSE
REACTIONS).
In clinical trials‚ the following laboratory results were observed:
- Cyclic fluctuations in the neutrophil counts were frequently observed in
patients with congenital or idiopathic neutropenia after initiation of
NEUPOGEN® therapy.
- Platelet counts were generally at the upper limits of normal prior to
NEUPOGEN® therapy. With NEUPOGEN®
therapy‚ platelet counts decreased but usually remained within normal limits
(see ADVERSE
REACTIONS).
- Early myeloid forms were noted in peripheral blood in most patients‚
including the appearance of metamyelocytes and myelocytes. Promyelocytes and
myeloblasts were noted in some patients.
- Relative increases were occasionally noted in the number of circulating
eosinophils and basophils. No consistent increases were observed with
NEUPOGEN® therapy.
- As in other trials‚ increases were observed in serum uric acid‚ lactic
dehydrogenase‚ and serum alkaline phosphatase.
Drug InteractionDrug interactions between NEUPOGEN® and
other drugs have not been fully evaluated. Drugs which may potentiate the
release of neutrophils‚ such as lithium‚ should be used with caution.
Increased hematopoietic activity of the bone marrow in response to growth
factor therapy has been associated with transient positive bone imaging changes.
This should be considered when interpreting bone-imaging results.
Carcinogenesis, Mutagenesis,
Impairment of FertilityThe carcinogenic potential of NEUPOGEN®
has not been studied. NEUPOGEN® failed to induce
bacterial gene mutations in either the presence or absence of a drug
metabolizing enzyme system. NEUPOGEN® had no observed
effect on the fertility of male or female rats‚ or on gestation at doses up to
500 mcg/kg.
Pregnancy Category CNEUPOGEN® has been shown to have adverse
effects in pregnant rabbits when given in doses 2 to 10 times the human dose.
Since there are no adequate and well-controlled studies in pregnant women, the
effect, if any, of NEUPOGEN® on the developing fetus or
the reproductive capacity of the mother is unknown. However, the scientific
literature describes transplacental passage of NEUPOGEN®
when administered to pregnant rats during the latter part of gestation18 and apparent transplacental passage of NEUPOGEN® when administered to pregnant humans by ≤ 30 hours prior to
preterm delivery (≤ 30 weeks gestation).19 NEUPOGEN® should be used during pregnancy only if the potential benefit
justifies the potential risk to the fetus.
In rabbits‚ increased abortion and embryolethality were observed in animals
treated with NEUPOGEN® at 80 mcg/kg/day. NEUPOGEN® administered to pregnant rabbits at doses of 80 mcg/kg/day
during the period of organogenesis was associated with increased fetal
resorption‚ genitourinary bleeding‚ developmental abnormalities‚ decreased body
weight‚ live births‚ and food consumption. External abnormalities were not
observed in the fetuses of dams treated at 80 mcg/kg/day. Reproductive studies
in pregnant rats have shown that NEUPOGEN® was not
associated with lethal‚ teratogenic‚ or behavioral effects on fetuses when
administered by daily IV injection during the period of organogenesis at dose
levels up to 575 mcg/kg/day.
In Segment III studies in rats‚ offspring of dams treated at > 20
mcg/kg/day exhibited a delay in external differentiation (detachment of auricles
and descent of testes) and slight growth retardation‚ possibly due to lower body
weight of females during rearing and nursing. Offspring of dams treated at 100
mcg/kg/day exhibited decreased body weights at birth‚ and a slightly reduced
4-day survival rate.
Nursing MothersIt is not known whether NEUPOGEN® is
excreted in human milk. Because many drugs are excreted in human milk‚ caution
should be exercised if NEUPOGEN® is administered to a
nursing woman.
Pediatric UseIn a phase 3 study to assess the safety and efficacy of
NEUPOGEN® in the treatment of SCN, 120 patients with a
median age of 12 years were studied. Of the 120 patients, 12 were infants (1
month to 2 years of age), 47 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 531 patients
in the surveillance study as of 31 December 1997, 32 were infants, 200 were
children, and 68 were adolescents (see CLINICAL
EXPERIENCE, INDICATIONS AND
USAGE, LABORATORY
MONITORING, DOSAGE AND
ADMINISTRATION).
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 NEUPOGEN® treatment. The relationship
of these events to NEUPOGEN® administration is unknown
(see WARNINGS,
ADVERSE
REACTIONS).
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 NEUPOGEN® 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.
The safety and efficacy in neonates and patients with autoimmune neutropenia
of infancy have not been established.
In the cancer setting‚ 12 pediatric patients with neuroblastoma have received
up to 6 cycles of cyclophosphamide‚ cisplatin‚ doxorubicin‚ and etoposide
chemotherapy concurrently with NEUPOGEN®; in this
population‚ NEUPOGEN® was well tolerated. There was one
report of palpable splenomegaly associated with NEUPOGEN®
therapy; however‚ the only consistently reported adverse event was
musculoskeletal pain‚ which is no different from the experience in the adult
population.
Geriatric UseAmong 855 subjects enrolled in 3 randomized, placebo-controlled
trials of NEUPOGEN® use following 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, and other clinical experience has not
identified differences in the responses between elderly and younger patients.
Clinical studies of NEUPOGEN® in other approved
indications (ie, bone marrow transplant 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.