Granix

Recommended Dosage

The recommended dose of GRANIX is 5 mcg/kg per day administered as a subcutaneous injection. Administer the first dose of GRANIX no earlier than 24 hours following myelosuppressive chemotherapy. Do not administer GRANIX within 24 hours prior to chemotherapy.

Daily dosing with GRANIX should continue until the expected neutrophil nadir is passed and the neutrophil count has recovered to the normal range. Monitor complete blood count (CBC) prior to chemotherapy and twice per week until recovery.

General Considerations for Administration

GRANIX may be administered by either a healthcare professional, a patient or caregiver. Before a decision is made to allow GRANIX to be administered by a patient or caregiver, ensure that the patient is an appropriate candidate for self-administration or administration by a caregiver. Proper training on storage, preparation, and administration technique should be provided. If a patient or caregiver is not an appropriate candidate for any reason, then in such patients, GRANIX should be administered by a healthcare professional.

Dispense only the prefilled syringe without a safety needle guard device to patient or caregiver. Instruct patients and caregivers to follow the Instructions for Use provided with the GRANIX prefilled syringe to properly administer an injection after training by a healthcare professional.

Visually inspect parenteral drug products for particulate matter and discoloration prior to administration. Do not administer GRANIX if discoloration or particulates are observed.

The prefilled syringe and vial are for single-dose only. Discard unused portions. GRANIX and all its components are not made with natural rubber latex.

Recommended sites for subcutaneous GRANIX injections include the abdomen (except for the two-inch area around the navel), the front of the middle thighs, the upper outer areas of the buttocks, or the upper back portion of the upper arms. The injection site should be varied daily. GRANIX should not be injected into an area that is tender, red, bruised, or hard, or that has scars or stretch marks.

Important Administration Instructions for Healthcare Professionals

Hold the syringe assembly by the open sides of the device and remove the needle shield.

Expel any extra volume depending on dose needed.

Inject GRANIX subcutaneously as recommended [see Dosage and Administration (2.2)].

Push the plunger as far as it will go to inject all the medication. Injection of the entire prefilled syringe contents is necessary to activate the needle guard.

With the plunger still pressed all the way down, remove the needle from the skin.

Slowly let go of the plunger and allow the empty syringe to move up inside the device until the entire needle is guarded.

Discard the syringe assembly in approved containers.

Pregnancy

Risk Summary

The limited published data on filgrastim product use during pregnancy are insufficient to inform a drug-associated risk. In animal reproduction studies, administration of tbo-filgrastim to pregnant rabbits during organogenesis resulted in increased spontaneous abortion and fetal malformations at systemic exposures 50 to 90 times the human exposure expected at the recommended human dose (see Data). GRANIX should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

The estimated background risk of major birth defects and miscarriage for the indicated population(s) are 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% to 4% and 15% to 20%, respectively.

Data

Animal Data

In an embryofetal developmental study, pregnant rabbits were administered subcutaneous doses of tbo-filgrastim during the period of organogenesis at 1, 10 and 100 mcg/kg/day. Increased abortions were evident in rabbits treated with tbo-filgrastim at 100 mcg/kg/day. This dose was maternally toxic as demonstrated by reduced body weight. Other embryofetal findings at this dose level consisted of post-implantation loss‚ decrease in mean live litter size and fetal weight, and fetal malformations such as malformed hind limbs and cleft palate. The dose of 100 mcg/kg/day corresponds to a systemic exposure (AUC) of approximately 50 to 90 times the exposures observed in patients treated with the clinical tbo-filgrastim dose of 5 mcg/kg/day.

Lactation

No data are available regarding the presence of tbo-filgrastim in human milk, the effects of the drug on the breastfed child, or the effects of the drug on milk production. Another filgrastim product was detected in human milk for up to 3 days after filgrastim administration. Because of the potential for serious adverse reactions in the breastfed child, including splenic rupture, acute respiratory distress syndrome and serious allergic reactions, advise patients not to breastfeed during treatment with GRANIX and for 2 weeks after the last dose. 

Pediatric Use

The safety and effectiveness of GRANIX have been established for pediatric patients 1 month to < 17 years old (no data for the age group < 1 month old).  Use of GRANIX in these age groups is supported by evidence from adequate and well-controlled studies of GRANIX in adults [see Clinical Studies (14)] with additional safety and pharmacokinetics data from a single-arm trial of 50 pediatric patients with solid tumors treated with GRANIX for chemotherapy-induced neutropenia. The 50 pediatric patients had a median age of 9.2 years (range, 1.4 to 15.9 years); 2 were infants (1 month to < 2 years old), 30 were children (2 to < 12 years old), and 18 were adolescents (12 to < 17 years old).  The pharmacokinetics and safety profile of GRANIX in the pediatric population were similar to those seen in adults [see Adverse Reactions , Clinical Pharmacology ]. 

Geriatric Use

Among 677 cancer patients enrolled in clinical trials of GRANIX, a total of 111 patients were 65 years of age and older, and 14 patients were 75 years and older. No overall differences in safety or effectiveness were observed between patients age 65 and older and younger patients.

Splenic Rupture

Splenic rupture, including fatal cases, can occur following administration of filgrastim products. Evaluate patients who report upper abdominal or shoulder pain for an enlarged spleen or splenic rupture. Discontinue GRANIX if splenic rupture is suspected or confirmed.

Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) can occur in patients receiving filgrastim products. Evaluate patients who develop fever and lung infiltrates or respiratory distress after receiving GRANIX, for ARDS. Discontinue GRANIX in patients with ARDS.

Serious Allergic Reactions

Serious allergic reactions, including anaphylaxis, can occur in patients receiving GRANIX. Reactions can occur on initial exposure. The administration of antihistamines‚ steroids‚ bronchodilators‚ and/or epinephrine may reduce the severity of the reactions. Permanently discontinue GRANIX in patients with serious allergic reactions. Do not administer GRANIX to patients with a history of serious allergic reactions to filgrastim or pegfilgrastim.

Sickle Cell Disorders

Severe and sometimes fatal sickle cell crises can occur in patients with sickle cell disorders receiving filgrastim products. Discontinue GRANIX if sickle cell crisis occurs.

Glomerulonephritis

Glomerulonephritis can occur in patients receiving filgrastim products. The diagnoses were based on azotemia, hematuria (microscopic and macroscopic), proteinuria, and renal biopsy. Generally, events of glomerulonephritis resolved after dose reduction or discontinuation of the filgrastim product. If glomerulonephritis is suspected, evaluate for cause. If causality is likely, consider dose reduction or interruption of GRANIX.

Capillary Leak Syndrome

Capillary leak syndrome (CLS) can occur in patients receiving filgrastim products and is characterized by hypotension, hypoalbuminemia, edema and hemoconcentration. Episodes vary in frequency, severity and may be life-threatening if treatment is delayed. Patients who develop symptoms of capillary leak syndrome should be closely monitored and receive standard symptomatic treatment, which may include a need for intensive care.

Potential for Tumor Growth Stimulatory Effects on Malignant Cells

The granulocyte colony-stimulating factor (G‑CSF) receptor through which GRANIX acts has been found on tumor cell lines. The possibility that GRANIX acts as a growth factor for any tumor type, including myeloid malignancies and myelodysplasia, diseases for which GRANIX is not approved, cannot be excluded.

Myelodysplastic Syndrome and Acute Myeloid Leukemiain Patients with Breast and Lung Cancer

Patients with Severe Chronic Neutropenia

Confirm the diagnosis of SCN before initiating GRANIX therapy.

MDS and AML have been reported to occur in the natural history of congenital neutropenia without cytokine therapy. Cytogenetic abnormalities, transformation to MDS, and AML have also been observed in patients treated with GRANIX for SCN. Based on available data including a postmarketing surveillance study, the risk of developing MDS and AML appears to be confined to the subset of patients with congenital neutropenia. Abnormal cytogenetics and MDS have been associated with the eventual development of myeloid leukemia. The effect of GRANIX on the development of abnormal cytogenetics and the effect of continued GRANIX administration in patients with abnormal cytogenetics or MDS are unknown. Monitor patients for signs and symptoms of MDS/AML in these settings. If a patient with SCN develops abnormal cytogenetics or myelodysplasia‚ the risks and benefits of continuing GRANIX should be carefully considered.

Patients with Breast and Lung Cancer

MDS and AML have been associated with the use of GRANIX in conjunction with chemotherapy and/or radiotherapy in patients with breast and lung cancer. Monitor patients for signs and symptoms of MDS/AML in these settings.

Leukocytosis

White blood cell counts of 100‚000/mm3 or greater were observed in approximately 2% of patients receiving filgrastim products at dosages above 5 mcg/kg/day.  In patients with cancer receiving GRANIX as an adjunct to myelosuppressive chemotherapy‚ to avoid the potential risks of excessive leukocytosis‚ it is recommended that GRANIX therapy be discontinued if the ANC surpasses 10‚000/mm3 after the chemotherapy-induced ANC nadir has occurred.  Monitor CBCs at least twice weekly during therapy. Dosages of GRANIX that increase the ANC beyond 10‚000/mm3 may not result in any additional clinical benefit.  In patients with cancer receiving myelosuppressive chemotherapy‚ discontinuation of filgrastim products therapy usually resulted in a 50% decrease in circulating neutrophils within 1 to 2 days‚ with a return to pretreatment levels in 1 to 7 days.

Simultaneous Use with Chemotherapy and Radiation Therapy Not Recommended

The safety and efficacy of filgrastim products, including GRANIX, 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 GRANIX in the period 24 hours before through 24 hours after the administration of cytotoxic chemotherapy [see Dosage and Administration ].

The safety and efficacy of GRANIX have not been evaluated in patients receiving concurrent radiation therapy. Avoid the simultaneous use of GRANIX with chemotherapy and radiation therapy.

Nuclear Imaging

Increased hematopoietic activity of the bone marrow in response to growth factor therapy has been associated with transient positive bone-imaging changes.  Consider this when interpreting bone-imaging results.

Aortitis

Aortitis has been reported in patients receiving another filgrastim product.  It may occur as early as the first week after start of therapy.  Manifestations may include generalized signs and symptoms such as fever, abdominal pain, malaise, back pain, and increased inflammatory markers (e.g., c‑reactive protein and white blood cell count).  Consider aortitis in patients who develop these signs and symptoms without known etiology.  Discontinue GRANIX if aortitis is suspected.

Alveolar Hemorrhage

Alveolar hemorrhage manifesting as pulmonary infiltrates and hemoptysis requiring hospitalization has been reported in healthy donors undergoing peripheral blood progenitor cell (PBPC) collection treated with another filgrastim product. Hemoptysis resolved with discontinuation of filgrastim. The use of GRANIX for PBPC mobilization in healthy donors is not an approved indication.

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.

Adverse Reactions in Adult Patients

GRANIX clinical trials safety data are based upon the results of three randomized clinical trials in patients receiving myeloablative chemotherapy for breast cancer (N=348), lung cancer (N=240) and non-Hodgkin’s lymphoma (N=92). In the breast cancer study, 99% of patients were female, the median age was 50 years, and 86% of patients were Caucasian. In the lung cancer study, 80% of patients were male, the median age was 58 years, and 95% of patients were Caucasian. In the non-Hodgkin’s lymphoma study, 52% of patients were male, the median age was 55 years, and 88% of patients were Caucasian. In all three studies a placebo (Cycle 1 of the breast cancer study only) or a non-U.S.-approved filgrastim product were used as controls. Both GRANIX and the non-U.S.-approved filgrastim product were administered at 5 mcg/kg subcutaneously once daily beginning one day after chemotherapy for at least five days and continued to a maximum of 14 days or until an ANC of ≥10,000 x 106/L after nadir was reached.

Bone pain was the most frequent treatment-emergent adverse reaction that occurred in at least 1% or greater in patients treated with GRANIX at the recommended dose and was numerically two times more frequent than in the placebo group. The overall incidence of bone pain in Cycle 1 of treatment was 3.4% (3.4% GRANIX, 1.4% placebo, 7.5% non-U.S.-approved filgrastim product).

Leukocytosis
In clinical studies, leukocytosis (WBC counts > 100,000 x 106/L) was observed in less than 1% patients with non-myeloid malignancies receiving GRANIX. No complications attributable to leukocytosis were reported in clinical studies.

Additional Adverse Reactions
Other adverse reactions known to occur following administration of filgrastim products include myalgia, headache, vomiting, cutaneous vasculitis and thrombocytopenia.

Adverse Reactions in Pediatric Patients
GRANIX clinical trials safety data in pediatric patients are based upon the results of one single-arm clinical trial in 50 pediatric patients who received myelosuppressive chemotherapy for treatment of solid tumors without marrow involvement [see Use in Special Populations ]. In this study, GRANIX was administered at 5 mcg/kg subcutaneously once daily beginning one day after chemotherapy.  The most common (>5%) adverse reactions included thrombocytopenia (34%), pyrexia (8%), pain in extremity (6%), headache (6%) and diarrhea (6%).

Postmarketing Experience

The following adverse reactions have been identified during post-approval use of GRANIX. 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.

• Sweet’s syndrome (acute febrile neutrophilic dermatosis), asthenia, diarrhea, and fatigue

Mechanism of Action

Tbo-filgrastim is a human granulocyte colony-stimulating factor (G-CSF) produced by recombinant DNA technology. Tbo-filgrastim binds to G-CSF receptors and stimulates proliferation of neutrophils. G-CSF is known to stimulate differentiation commitment and some end-cell functional activation, which increases neutrophil counts and activity.

Pharmacodynamics

The time to the maximum ANC level was between 3 to 5 days and returned to baseline by 21 days following completion of chemotherapy.  Doubling the tbo-filgrastim subcutaneous dose from 5 mcg/kg to 10 mcg/kg resulted in a 16% to 19% increase in the maximum ANC level and a 33% to 36% increase in the area under the effect curve for ANC.

Cardiac Electrophysiology

At an intravenous dose of 5 mcg/kg, tbo-filgrastim did not prolong the QT interval to any clinically relevant extent.

Pharmacokinetics

Tbo-filgrastim exhibits nonlinear pharmacokinetics. Increasing the dose of subcutaneous GRANIX from 5 to 10 mcg/kg resulted in an approximate 2.5-fold increase in the maximum serum concentration (Cmax) and 3.0-fold increase in the area under the curve (AUC). In adult patients enrolled across three studies, subcutaneous GRANIX 5 mcg/kg resulted in median time to maximal serum tbo-filgrastim concentrations (Tmax) within 4 to 6 hours. Geometric mean [coefficient of variation (CV%)] serum Cmax was 20 to 31 ng/mL [24% to 65%] within 4 to 6 hours. Geometric mean serum tbo-filgrastim area under the curve (AUC0-12h) ranged from 151 to 227 ng/mL*h [24% to 60%]. No accumulation in serum tbo-filgrastim concentrations was observed after multiple dosing.

Absorption

The absolute bioavailability of 5 mcg/kg subcutaneous tbo-filgrastim was 33%.

Metabolism/Elimination

Tbo-filgrastim clearance is primarily dependent on G-CSF receptor-mediated clearance which can be saturated by high serum concentrations of tbo-filgrastim and diminished in neutropenia. The median serum elimination half-life of tbo-filgrastim (5 mcg/kg sc) was 3.0 to 3.5 hours.

Specific Populations

No sex-related differences were observed.

Pediatric Patients:

The geometric mean [coefficient of variation (CV%)] of Cmax was 18 ng/mL (56%) and AUC0-12h was 130 ng*hr/mL (52%) following subcutaneous administration of GRANIX 5 mcg/kg in 49 pediatric patients (1.4 to 15.9 years) after chemotherapy. No clinically relevant differences in the pharmacokinetics of GRANIX were observed between infants, children and adolescents.

Patients with Renal or Hepatic Impairment:

Mild renal impairment (creatinine clearance 60 to 89 mL/min by Cockcroft-Gault) had no effect on tbo-filgrastim pharmacokinetics. The pharmacokinetics in patients with moderate and severe renal impairment has not been studied. The pharmacokinetics in patients with hepatic impairment has not been studied.

Immunogenicity

The observed incidence of anti-drug antibodies is highly dependent on the sensitivity and specificity of the assay. Differences in assay methods preclude meaningful comparisons of the incidence of anti-drug antibodies in the studies described below with the incidence of anti-drug antibodies in other studies, including those of GRANIX or of other filgrastim products.

While available data suggest that 1.4% of patients developed binding antibodies to filgrastim, the nature and specificity of these antibodies has not been adequately studied. Because of the low occurrence of anti- drug antibodies, the effect of these antibodies on the pharmacokinetics, pharmacodynamics, safety, and/or effectiveness of GRANIX is unknown.

Cytopenias resulting from an antibody response to exogenous growth factors have been reported on rare occasions in patients treated with other recombinant growth factors.

Carcinogenesis, Mutagenesis, Impairment of Fertility

Carcinogenicity and genetic toxicology studies have not been conducted with tbo-filgrastim.

A fertility study was not conducted with tbo-filgrastim. Toxicology studies of up to 26 weeks in rats or monkeys did not reveal findings in male or female reproductive organs that would suggest impairment of fertility.