At a glance
Neupogen® (Filgrastim) is a prescription medication that can help produce white blood cells, making cancer patients less vulnerable to infections. Patients exposed to high levels of radiation may not be able to produce new white blood cells. Neupogen® can speed up the process of creating white blood cells in these patients.
Overview
Neupogen® is indicated to decrease the incidence of infection resulting from neutropenia (low white blood cells counts) in cancer patients receiving treatment. Similarly, Neupogen® is also expected to help patients who have bone marrow damage from very high doses of radiation.
A person who receives a very high dose of penetrating ionizing radiation may experience bone marrow damage, possibly resulting in infection (triggered by neutropenia) and uncontrolled bleeding. A very high dose is greater or equal to 2 Gray (Gy) to the whole body over a short duration.
Bone marrow suppression occurs with Acute Radiation Syndrome. Medications that speed up blood cell production, including Neupogen, may help the body heal and protect from infections.
In March 2015, the U.S. Food and Drug Administration (FDA) approved Neupogen® to treat people who have received high doses of radiation.
How Neupogen® works
Patients who have been exposed to high doses of radiation will not be able to produce new white blood cells. This leads to a significant decrease in the number of white blood cells (including neutrophils) in circulation. These patients' own bone marrow will eventually create new blood cells, but this process is slow. Until their white blood cell counts rise, these patients are at a high risk of death from infection due to neutropenia.
Neupogen® can accelerate the process of creating white blood cells. This will reduce the time that the patient is vulnerable to infection.
Use
Neupogen® is given to help cancer patients and patients exposed to high doses of radiation produce white blood cells. By producing white blood cells at a faster pace, Neupogen® helps to avoid or minimize the incidence of infections from neutropenia. Neupogen® cannot help the patient in eliminating or blocking the absorption of radioisotopes or any radioactive material from the body.
Administration
Who can take Neupogen®?
Adults and children of all ages can take Neupogen®. This includes pregnant and nursing women if Neupogen® is deemed clinically appropriate. People who have known hypersensitivity to filgrastim, peg-filgrastim, or any component of filgrastim should not take Neupogen®. Components of filgrastim includes E. coli-derived proteins.
Pregnant women (Category C)
There is a lack of adequate and well-controlled studies in pregnant women. Some adverse effects have been observed in animal studies. Neupogen® should be used during pregnancy only if the potential benefit outweighs the potential risk to the fetus.
Nursing mothers
It 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 women who are breastfeeding.
Note: Neupogen® is available in single-dose vials and prefilled syringes. The needle cap on the prefilled syringes contains dry natural rubber, derived from latex. People with known severe latex allergies should take precautions when handling or administering Neupogen® from prefilled syringes.
How is Neupogen® given?
According to the FDA-approved drug label, the treatment plan for patients acutely exposed to myelosuppressive doses of radiation (hematopoietic syndrome of the acute radiation syndrome) is to give 10 micrograms per kilogram of patient weight (10 mcg/kg) daily by subcutaneous injection. Administer Neupogen® as soon as possible after suspected or confirmed exposure to radiation doses greater than 2 gray (Gy).
The FDA-approved drug label recommends that clinicians obtain a baseline Complete Blood Count (CBC) followed by serial CBCs approximately every third day until the absolute neutrophil count (ANC) remains greater than 1,000/mm3 for three consecutive CBCs. Do not delay administration of Neupogen® if a CBC is not readily available.
Discontinue Neupogen® therapy until the ANC remains greater than 1,000/mm3 for three consecutive CBCs or greater than 10,000/mm3 after a radiation-induced nadir. The safe use of Neupogen® and duration of Neupogen® treatment will require periodic monitoring of ANC levels as resources permit.
Side effects
The most common side effect of Neupogen® is mild to moderate bone pain that may require an analgesic. Other possible side effects of Neupogen® include fever, diarrhea, skin rash and weakness.
Enlargement and rupture of the spleen can rarely occur in patients who are receiving Neupogen®. Patients who develop abdominal pain, particularly in the left side, or left shoulder pain while receiving the drug should be evaluated as soon as possible.
Certain serious conditions have been reported in patients receiving Neupogen®:
- Sickle cell crisis
- Acute respiratory distress syndrome
- Splenic ruptures
- Glomerulonephritis
- Alveolar hemorrhage and hemoptysis
- Capillary leak syndrome
- Thrombocytopenia
- Leukocytosis
- Cutaneous vasculitis
- Serious allergic reactions (i.e., anaphylaxis)
If any of these conditions are present, discontinue therapy.
Full information on warnings and precautions.
Availability
Neupogen® is commercially available in the marketplace. Use Neupogen® according to the FDA-approved label in patients exposed to high doses of radiation. Neupogen® may be distributed through the Strategic National Stockpile (SNS) when local supplies are depleted or not available during an emergency.
More detailed information regarding Neupogen® and any emergency use instructions will be provided through state and local public health officials.