Warnings for Stimufend
Included as part of the "PRECAUTIONS" Section
Precautions for Stimufend
Splenic Rupture
Splenic rupture, including fatal cases, can occur following the administration of pegfilgrastim products. Evaluate for an enlarged spleen or splenic rupture in patients who report left upper abdominal or shoulder pain after receiving Stimufend.
Acute Respiratory Distress Syndrome
Acute respiratory distress syndrome (ARDS) can occur in patients receiving pegfilgrastim products. Evaluate patients who develop fever and lung infiltrates or respiratory distress after receiving Stimufend for ARDS. Discontinue Stimufend in patients with ARDS.
Serious Allergic Reactions
Serious allergic reactions, including anaphylaxis, can occur in patients receiving pegfilgrastim products. The majority of reported events occurred upon initial exposure. Allergic reactions, including anaphylaxis, can recur within days after the discontinuation of initial anti-allergic treatment. Permanently discontinue Stimufend in patients with serious allergic reactions. Do not administer Stimufend to patients with a history of serious allergic reactions to pegfilgrastim products or filgrastim products.
Use In Patients With Sickle Cell Disorders
Severe and sometimes fatal sickle cell crises can occur in patients with sickle cell disorders receiving pegfilgrastim products. Discontinue Stimufend if sickle cell crisis occurs.
Glomerulonephritis
Glomerulonephritis has occurred in patients receiving pegfilgrastim products. The diagnoses were based upon azotemia, hematuria (microscopic and macroscopic), proteinuria, and renal biopsy. Generally, events of glomerulonephritis resolved after dose-reduction or discontinuation of pegfilgrastim products. If glomerulonephritis is suspected, evaluate for cause. If causality is likely, consider dose-reduction or interruption of Stimufend.
Leukocytosis
White blood cell (WBC) counts of 100 x 109/L or greater have been observed in patients receiving pegfilgrastim products. Monitoring of complete blood count (CBC) during Stimufend therapy is recommended.
Thrombocytopenia
Thrombocytopenia has been reported in patients receiving pegfilgrastim products. Monitor platelet counts.
Capillary Leak Syndrome
Capillary leak syndrome has been reported after G-CSF administration, including pegfilgrastim 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 pegfilgrastim products and filgrastim products act has been found on tumor cell lines. The possibility that pegfilgrastim products act as a growth factor for any tumor type, including myeloid malignancies and myelodysplasia, diseases for which pegfilgrastim products are not approved, cannot be excluded.
Myelodysplastic Syndrome (MDS) And Acute Myeloid Leukemia (AML) In Patients WithBreast And Lung Cancer
MDS and AML have been associated with the use of pegfilgrastim products 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.
Aortitis
Aortitis has been reported in patients receiving pegfilgrastim products. 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 Stimufend if aortitis is suspected.
Nuclear Imaging
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.
Patient Counseling Information
Advise the patient to read the FDA-approved patient labeling (PATIENT INFORMATION and Instructions for Use). Advise patients of the following risks and potential risks with Stimufend:
- Splenic rupture and splenomegaly
- Acute Respiratory Distress Syndrome
- Serious allergic reactions
- Sickle cell crisis
- Glomerulonephritis
- Increased risk of Myelodysplastic Syndrome and/or Acute Myeloid Leukemia in patients with breast and lung cancer who receive Stimufend in conjunction with chemotherapy and/or radiation therapy
- Capillary Leak Syndrome
- Aortitis
Advise patients acutely exposed to myelosuppressive doses of radiation (Hematopoietic Subsyndrome of Acute Radiation Syndrome) that efficacy studies of pegfilgrastim products for this indication could not be conducted in humans for ethical and feasibility reasons and that, therefore, approval of this use was based on efficacy studies conducted in animals [see Clinical Studies].
Instruct patients who self-administer Stimufend using the single-dose pre-filled syringe of the:
- Importance of following the Instructions for Use (see INSTRUCTIONS FOR USE).
- Dangers of reusing syringes.
- Importance of following local requirements for proper disposal of used syringes.
Nonclinical Toxicology
Carcinogenesis, Mutagenesis, Impairment Of Fertility
No carcinogenicity or mutagenesis studies have been performed with pegfilgrastim products.
Pegfilgrastim did not affect reproductive performance or fertility in male or female rats at cumulative weekly doses approximately 6 to 9 times higher than the recommended human dose (based on body surface area).
Use In Specific Populations
Pregnancy
Risk Summary
Although available data with Stimufend or pegfilgrastim product use in pregnant women are insufficient to establish whether there is a drug associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes, there are available data from published studies in pregnant women exposed to filgrastim products. These studies have not established an association of filgrastim product use during pregnancy with major birth defects, miscarriage, or adverse maternal or fetal outcomes.
In animal studies, no evidence of reproductive/developmental toxicity occurred in the offspring of pregnant rats that received cumulative doses of pegfilgrastim approximately 10 times the recommended human dose (based on body surface area). In pregnant rabbits, increased embryolethality and spontaneous abortions occurred at 4 times the maximum recommended human dose simultaneously with signs of maternal toxicity (see Data).
The estimated background risk of major birth defects and miscarriage for the indicated population 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 risks of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively.
Data
Animal Data
Pregnant rabbits were dosed with pegfilgrastim subcutaneously every other day during the period of organogenesis. At cumulative doses ranging from the approximate human dose to approximately 4 times the recommended human dose (based on body surface area), the treated rabbits exhibited decreased maternal food consumption, maternal weight loss, as well as reduced fetal body weights and delayed ossification of the fetal skull; however, no structural anomalies were observed in the offspring from either study. Increased incidences of post-implantation losses and spontaneous abortions (more than half the pregnancies) were observed at cumulative doses approximately 4 times the recommended human dose, which were not seen when pregnant rabbits were exposed to the recommended human dose.
Three studies were conducted in pregnant rats dosed with pegfilgrastim at cumulative doses up to approximately 10 times the recommended human dose at the following stages of gestation: during the period of organogenesis, from mating through the first half of pregnancy, and from the first trimester through delivery and lactation. No evidence of fetal loss or structural malformations was observed in any study. Cumulative doses equivalent to approximately 3 and 10 times the recommended human dose resulted in transient evidence of wavy ribs in fetuses of treated mothers (detected at the end of gestation but no longer present in pups evaluated at the end of lactation).
Lactation
Risk Summary
There are no data on the presence of pegfilgrastim products in human milk, the effects on the breastfed child, or the effects on milk production. Other 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 Stimufend and any potential adverse effects on the breastfed child from Stimufend or from the underlying maternal condition.
Pediatric Use
The safety and effectiveness of Stimufend have been established in pediatric patients. No overall differences in safety were identified between adult and pediatric patients based on postmarketing surveillance and review of the scientific literature.
Use of Stimufend in pediatric patients for chemotherapy-induced neutropenia is based on Stimufend’s approval as a biosimilar to pegfilgrastim and evidence from adequate and well-controlled studies of pegfilgrastim in adults with additional pharmacokinetic and safety data of pegfilgrastim in pediatric patients with sarcoma [see CLINICAL PHARMACOLOGY and Clinical Studies].
The use of Stimufend to increase survival in pediatric patients acutely exposed to myelosuppressive doses of radiation is based on Stimufend’s approval as a biosimilar to pegfilgrastim, evidence from efficacy studies of pegfilgrastim conducted in animals, and clinical data supporting the use of pegfilgrastim in patients with cancer receiving myelosuppressive chemotherapy. Efficacy studies of pegfilgrastim products could not be conducted in humans with acute radiation syndrome for ethical and feasibility reasons. Results from population modeling and simulation indicate that two weight-based doses of pegfilgrastim (Table 1) administered one week apart provide pediatric patients weighing less than 45 kg with exposures comparable to that of adults receiving two 6 mg doses one week apart [see DOSAGE AND ADMINISTRATION, CLINICAL PHARMACOLOGY and Clinical Studies].
Geriatric Use
Of the 932 patients with cancer who received pegfilgrastim in clinical studies, 139 (15%) were aged 65 and over, and 18 (2%) were aged 75 and over. No overall differences in safety or effectiveness were observed between patients aged 65 and older and younger patients.