Pegfilgrastim – Uses, Dosage, Side Effects, Interaction

Pegfilgrastim is a recombinant human granulocyte colony-stimulating factor used to stimulate the production of neutrophils and prevent febrile neutropenia or infections after myelosuppressive chemotherapy. Pegfilgrastim is a PEGylated form of the recombinant human granulocyte colony-stimulating factor (GCSF) analog filgrastim. It serves to stimulate the production of white blood cells (neutrophils). Pegfilgrastim treatment can be used to stimulate the bone marrow to produce more neutrophils to fight infection in patients undergoing chemotherapy.

Pegfilgrastim is a PEGylated form of the recombinant human granulocyte colony-stimulating factor (G-CSF) analog, filgrastim.[rx] The drug is approved for use to decrease the incidence of infection, as manifested by febrile neutropenia, in susceptible patients with non-myeloid cancer receiving myelosuppressive anti-cancer treatment.[rx] Although the risk of developing febrile neutropenia is less than 20% in many readily used chemotherapy regimens,[rx] infections pose risks of hospitalization and mortalities.[rx] Due to the relatively short circulating half-life of filgrastim, a 20 kDa PEG moiety was covalently conjugated to the N-terminus of filgrastim (at the methionine residue) to develop longer-acting pegfilgrastim.[rx,rx] Due to a longer half-life and slower elimination rate than filgrastim, pegfilgrastim requires less frequent dosing than filgrastim; however, pegfilgrastim has comparable pharmacological activity to filgrastim and binds to the G-CSF receptor to stimulate the proliferation, differentiation, and activation of neutrophils.[rx]

First developed by Amgen, pegfilgrastim was initially approved by the FDA in 2002 and marketed as Neulasta. It is typically administered via a subcutaneous injection. There are several pegfilgrastim biosimilars (Fulphila, Pelgraz or Lapelga, Pelmeg, Udenyca, Ziextenzo, Grasustek, Fylnetra, Stimufend) by Health Canada, European Union (EU), and FDA that are approved to reduce infection risk. These biosimilars are highly similar to the reference product, Neulasta, in terms of pharmacological and pharmacokinetic profile and conditions of use.[rx]

Mechanism of action

Neutrophils are short-lived immune cells that are highly susceptible to cell death following myelosuppressive chemotherapy. This marked reduction in neutrophil numbers during chemotherapy increases the risk of hospitalization, infection, and infection-related mortality. It also directly impacts the clinical outcome of patients if cases of febrile neutropenia require dose reductions or schedule delay of chemotherapy, thus reducing the clinical efficacy of chemotherapy and the patient benefit from receiving appropriate treatment.[rx]

G-CSF is an endogenous hematopoietic growth factor that stimulates granulopoietic cells of the neutrophil lineage. Pegfilgrastim mimics its biological actions and binds to the same G-CSF receptor expressed on cells of the myeloid lineages, such as granulocytic precursors and mature neutrophils.[rx] Upon binding of the ligand, the G-CSF receptor undergoes a conformational change and activates several downstream signaling pathways including JAK/STAT, PI3K/AKT, and MAPK/ERK.[rx] These pathways work to increase the proliferation and differentiation of granulocyte progenitor cells, induce maturation of the progenitor cells, and enhance the survival and function of mature neutrophils.[rx]

Pegfilgrastim is a recombinant human granulocyte colony-stimulating factor (G-CSF) that promotes the production, proliferation, and maturation of neutrophils, which are white blood cells involved in both innate and adaptive immune responses.[rx,rx] The safety and efficacy of pegfilgrastim in reducing the risk of febrile neutropenia and infections have been demonstrated in various tumor types and settings.[rx]

During chemotherapy-induced neutropenia, the clearance of pegfilgrastim is significantly reduced and the concentration of pegfilgrastim is sustained until the onset of neutrophil recovery.[rx] Serum concentrations of pegfilgrastim decline as the neutrophil count increases as neutrophil and neutrophil precursors are involved in cell-mediated clearance of the drug.[rx] Due to the addition of a polyethylene glycol group to its structure, Pegfilgrastim is a long-acting form of filgrastim with an extended serum half-life and reduced renal clearance.[rx] Although it is more slowly absorbed than filgrastim, self-regulation of pegfilgrastim is more efficient and the drug effects are maintained during one chemotherapy cycle (2-3 weeks).[rx]

Indications

  • Pegfilgrastim is indicated to decrease the incidence of infection, as manifested by febrile neutropenia, in patients with non­ myeloid malignancies receiving myelosuppressive anti-cancer drugs associated with a clinically significant incidence of febrile neutropenia.[rx]
  • It is also indicated to increase survival in patients acutely exposed to myelosuppressive doses of radiation (Hematopoietic Subsyndrome of Acute Radiation Syndrome).[rx]
  • Pegfilgrastim is indicated to decrease the incidence of infection, as manifested by febrile neutropenia, in people with non-myeloid malignancies receiving myelosuppressive anti-cancer drugs associated with a clinically significant incidence of febrile neutropenia; and to increase survival in people acutely exposed to myelosuppressive doses of radiation (hematopoietic subsyndrome of acute radiation syndrome).
  • Chemotherapy Induced Neutropenia
  • Hematopoietic Subsyndrome of Acute Radiation Syndrome
  • Infection
  • To decrease the incidence of infection, as manifested by febrile neutropenia, in patients with non-myeloid malignancies receiving myelosuppressive anticancer drugs associated with a clinically significant incidence of febrile neutropenia

FDA Approved Indications

Pegfilgrastim is a pegylated granulocyte colony-stimulating factor that is FDA-approved to decrease the risk of patients developing febrile neutropenia when receiving myelosuppressive chemotherapy regimens. For primary prophylaxis, the risk of developing febrile neutropenia should be 20% or higher, and there should be no other safer regimen that is equally effective available to the patient. Definable risk factors, as listed here, determine a patient’s chance for developing febrile neutropenia:

  • 65-years-old or older
  • Advanced disease
  • Previous chemotherapy or radiation therapy
  • Preexisting neutropenia or bone marrow involvement with a tumor
  • Infection
  • Open wounds or having undergone recent surgery
  • Poor performance or nutritional status
  • Impaired renal function
  • Inadequate liver function, mainly indicated by elevated bilirubin
  • Cardiovascular disease
  • Multiple comorbid conditions
  • HIV

It is important to note that the risk of developing febrile neutropenia is less than 20% in many readily used chemotherapy regimens. Therefore, it is essential to make individualized, patient-based decisions when deciding if the use of a granulocyte-colony-stimulating factor is required.

Pegfilgrastim is also FDA-approved to help increase the survival of patients exposed to myelosuppressive doses of radiation. Receiving acute myelosuppressive doses of radiation is a syndrome known as acute radiation syndrome, and pegfilgrastim’s indication is for the hematopoietic sub-syndrome.

Contraindications

  • Pegfilgrastim can cause hypersensitivity reactions. Therefore, it is contraindicated in patients who have experienced hypersensitivity to pegfilgrastim, filgrastim, or any component of the formulation.
  • acute myeloid leukemia, a type of blood cancer
  • sickle cell anemia
  • pain crisis in sickle cell disease
  • decreased blood platelets
  • capillary leak syndrome, a condition where fluid leaks out of small blood vessels
  • acute respiratory distress syndrome, a type of lung disorder
  • glomerulonephritis, a condition that affects the kidneys
  • myelodysplastic syndrome, a bone marrow disorder
  • rupture of the spleen
  • aortitis

Dosage

Strengths: apgf 6 mg/0.6 mL; 6 mg/0.6 mL; bmez 6 mg/0.6 mL; jmdb 6 mg/0.6 mL; cbqv 6 mg/0.6 mL; pbbk 6 mg/0.6 mL

Febrile Neutropenia

  • 6 mg subcutaneously ONCE per chemotherapy cycle, beginning at least 24 hours after completion of chemotherapy
  • Do not administer between 14 days before and 24 hours after the administration of cytotoxic chemotherapy.

Neutropenia Associated with Chemotherapy

  • 6 mg subcutaneously ONCE per chemotherapy cycle, beginning at least 24 hours after completion of chemotherapy
  • Do not administer between 14 days before and 24 hours after the administration of cytotoxic chemotherapy.

Neutropenia Associated with Radiation

  • 6 mg subcutaneously once a week
  • Duration of treatment: 2 weeks
  • Administer the first dose as soon as possible after suspected or confirmed exposure to radiation levels greater than 2 gray (Gy) and administer the second dose one week after the first dose.
  • A baseline complete blood count (CBC) should be obtained before dosing; however, therapy should not be delayed if a CBC is not readily available.
  • The healthcare provider should estimate the level of radiation exposure in the patient based on information from public health authorities, biodosimetry if available, or clinical findings such as time to onset of vomiting or lymphocyte depletion kinetics.

Pediatric Dose for Febrile Neutropenia

Pediatric patients:

  • Body weight less than 10 kg: 0.1 mg/kg subcutaneously once per chemotherapy cycle, beginning at least 24 hours after completion of chemotherapy
  • Body weight 10 to 20 kg: 1.5 mg subcutaneously ONCE per chemotherapy cycle, beginning at least 24 hours after completion of chemotherapy
  • Body weight 21 to 30 kg: 2.5 mg subcutaneously ONCE per chemotherapy cycle, beginning at least 24 hours after completion of chemotherapy
  • Body weight 31 to 44 kg: 4 mg subcutaneously ONCE per chemotherapy cycle, beginning at least 24 hours after completion of chemotherapy
  • Body weight 45 kg or greater: 6 mg subcutaneously ONCE per chemotherapy cycle, beginning at least 24 hours after completion of chemotherapy
  • The prefilled syringe is not designed to allow administration of doses less than 0.6 mL (6 mg) because it does not have graduation marks, which are necessary to accurately measure doses less than 0.6 mL; therefore, administration to patients requiring less than 0.6 mL is not recommended.
  • Do not administer between 14 days before and 24 hours after administration of cytotoxic chemotherapy.

Pediatric Dose for Neutropenia Associated with Chemotherapy

Pediatric patients:

  • Body weight less than 10 kg: 0.1 mg/kg subcutaneously once per chemotherapy cycle, beginning at least 24 hours after completion of chemotherapy
  • Body weight 10 to 20 kg: 1.5 mg subcutaneously ONCE per chemotherapy cycle, beginning at least 24 hours after completion of chemotherapy
  • Body weight 21 to 30 kg: 2.5 mg subcutaneously ONCE per chemotherapy cycle, beginning at least 24 hours after completion of chemotherapy
  • Body weight 31 to 44 kg: 4 mg subcutaneously ONCE per chemotherapy cycle, beginning at least 24 hours after completion of chemotherapy
  • Body weight 45 kg or greater: 6 mg subcutaneously ONCE per chemotherapy cycle, beginning at least 24 hours after completion of chemotherapy
  • The prefilled syringe is not designed to allow administration of doses less than 0.6 mL (6 mg) because it does not have graduation marks, which are necessary to accurately measure doses less than 0.6 mL; therefore, administration to patients requiring less than 0.6 mL is not recommended.
  • Do not administer between 14 days before and 24 hours after administration of cytotoxic chemotherapy.

Pediatric Dose for Neutropenia Associated with Radiation

Children:

  • Body weight less than 10 kg: 0.1 mg/kg subcutaneously once a week
  • Body weight 10 to 20 kg: 1.5 mg subcutaneously once a week
  • Body weight 21 to 30 kg: 2.5 mg subcutaneously once a week
  • Body weight 31 to 44 kg: 4 mg subcutaneously once a week
  • Body weight 45 kg or greater: 6 mg subcutaneously once a week
  • Duration of treatment: 2 weeks
  • Administer the first dose as soon as possible after suspected or confirmed exposure to radiation levels greater than 2 Gy and administer the second dose one week after the first dose.
  • A baseline CBC should be obtained before dosing; however, therapy should not be delayed if a CBC is not readily available.
  • The healthcare provider should estimate the level of radiation exposure in the patient based on information from public health authorities, biodosimetry if available, or clinical findings such as time to onset of vomiting or lymphocyte depletion kinetics.

Administration advice:

  • Avoid shaking; this drug should be allowed to come to room temperature prior to administration.
  • Manually-administered injections should be given into the abdomen, thigh, or upper arm.
  • On-body injectors (OBI) should be applied to intact, non-irritated skin on the back of the arm or abdomen.

Side Effects

The Most Common

  • bone pain
  • pain in arms or legs
  • pain in the left upper part of the stomach or the tip of your left shoulder
  • fever, shortness of breath, trouble breathing, fast breathing
  • swelling of the face, throat, or around the mouth or eyes; hives; rash; itching; trouble swallowing or breathing; rapid heartbeat; or sweating
  • swelling of your face or ankles, bloody or dark colored urine, decreased urination
  • unusual bleeding or bruising, fever, or tiredness
  • fever, abdominal pain, back pain, feeling unwell
  • swelling of stomach area or other swelling, decreased urination, trouble breathing, dizziness, tiredness
  • Bone pain
  • chest pain
  • difficult or labored breathing
  • eye pain
  • a general feeling of illness
  • headache

More common

  • Chills
  • cough
  • fever
  • sore throat
  • ulcers, sores, or white spots in the mouth
  • Belching
  • change in sense of taste
  • constipation
  • cracked lips
  • diarrhea
  • hair loss or thinning of the hair
  • heartburn
  • indigestion
  • joint pain
  • lack or loss of strength
  • loss of appetite
  • muscle soreness
  • swelling or inflammation of the mouth
  • trouble sleeping
  • vomiting
  • weakness, generalized
  • weight loss

Rare

  • Bluish lips or skin
  • pain left upper abdomen or shoulder
  • tightness in the chest
  • trouble breathing
  • Black, tarry stools
  • bleeding gums
  • bleeding, blistering, burning, coldness, discoloration of the skin, feeling of pressure, hives, infection, inflammation, itching, lumps, numbness, pain, rash, redness, scarring, soreness, stinging, swelling, tenderness, tingling, ulceration, or warmth at the injection site
  • blisters in the skin
  • blood in the urine or stools
  • chest pain
  • cloudy urine
  • decrease in how much or how often you urinate
  • difficulty with swallowing
  • dizziness
  • fainting or lightheadedness
  • fast heartbeat
  • flushing or redness of the skin
  • hives or welts, skin rash
  • itching, puffiness, or swelling of the eyelids or around the eyes, face, lips, or tongue
  • large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
  • lower back or side pain
  • nausea
  • painful or difficult urination
  • pinpoint red spots on the skin
  • sores on the skin
  • stomach pain
  • swelling of the hands, ankles, feet, or lower legs
  • swollen glands
  • unusual bleeding or bruising
  • unusual tiredness or weakness
  • unusually warm skin

Drug Interactions

Pregnancy and Lactation

AU TGA pregnancy category: B3
US FDA pregnancy category: Not Assigned

Pregnancy

No data available on the use of this drug in pregnant patients to inform a drug-related risk. Use of other filgrastim products has not established associations between use during pregnancy and birth defects, miscarriage, and/or adverse fetal/maternal effects.

Lactation

  • Use is not recommended, and a decision should be made to discontinue breastfeeding or discontinue the drug, taking into account the importance of the drug to the mother.
  • Excreted into human milk: Unknown
  • Excreted into animal milk: Data not available
  • Other recombinant granulocyte colony-stimulating factor (G-CSF) products are poorly secreted in breast milk, and G-CSFs are not orally absorbed by neonates.
  • The effects in the nursing infant are unknown.
  • A lactation surveillance programme in the UK is available.

How should this medicine be used?

Pegfilgrastim injection products come as a solution (liquid) in prefilled injection syringes to inject subcutaneously (under the skin), and in a prefilled automatic injection device (on-body injector) to apply to the skin. If you are using a pegfilgrastim injection product to decrease the risk of infection during chemotherapy, it is usually given as a single dose for each chemotherapy cycle, no sooner than 24 hours after the last dose of chemotherapy of the cycle is given, and more than 14 days before beginning the next chemotherapy cycle. If you are using pegfilgrastim injection because you have been exposed to harmful amounts of radiation, it is usually given as 2 single doses, 1 week apart. Your doctor will tell you exactly when you should use pegfilgrastim injection products.

Pegfilgrastim injection products may be given to you by a nurse or other healthcare provider, you may be told to inject the medication yourself at home, or you may receive a prefilled automatic injection device by the nurse or healthcare provider that will inject the medication automatically for you at home. If you will be injecting pegfilgrastim injection products yourself at home, or if you receive the prefilled automatic injection device, a healthcare provider will show you how to inject the medication, or how to manage the device. Your healthcare provider will also give you the manufacturer’s information for the patient. Ask your healthcare provider to explain any part that you do not understand. Use a pegfilgrastim injection product exactly as directed. Do not use more or less of it or use it more often than prescribed by your doctor.

Do not shake syringes containing pegfilgrastim solution. Always look at the pegfilgrastim solution before injecting. Do not use if the expiration date has passed, or if the pegfilgrastim solution has particles or looks cloudy or discolored.

If your pegfilgrastim solution comes in a prefilled automatic injection device, the device will usually be applied to your abdomen or the back of your arm by a nurse or other healthcare provider the day before you will receive the dose of pegfilgrastim. The next day (approximately 27 hours after the prefilled automatic injection device was applied to your skin), the dose of pegfilgrastim solution will be automatically injected subcutaneously over 45 minutes.

When you have the pegfilgrastim prefilled automatic injection device in place;

  • you should have a caregiver with you the first time you receive a dose of pegfilgrastim or anytime the prefilled automatic injection device is applied to the back of your arm.
  • you will need to monitor the prefilled automatic injection device while the entire dose of pegfilgrastim is injected into your body, so you should avoid activities and be in places that may interfere with monitoring while you are receiving the dose of filgrastim and for 1 hour afterward.
  • you should not travel, drive a car, or operate machinery 1 hour before and 2 hours after you receive your dose of pegfilgrastim with the prefilled automatic injection device (about 26 to 29 hours after it was applied).
  • you should make sure that you keep the prefilled automatic injection device at least 4 inches away from electric appliances and equipment including cell phones, cordless telephones, and microwave ovens.
  • you should avoid airport x-rays and request a manual pat down if you have to travel after the prefilled automatic injection device is applied to your body and before you receive your dose of pegfilgrastim.
  • you should immediately remove the prefilled automatic injection device if you have an allergic reaction while you are receiving your dose of pegfilgrastim by grabbing the edge of the adhesive pad and peeling it off. Call your doctor immediately and get emergency medical treatment.
  • you should call your doctor immediately if the prefilled automatic injection device comes off of your skin, if the adhesive becomes noticeably wet, if you see dripping from the device, or if the status light flashes red. You should keep the prefilled automatic injection device dry for 3 hours before you receive your dose of pegfilgrastim to help you notice if your device starts to leak while you are receiving your dose.
  • you should avoid being exposed to medical imaging studies (X-ray scan, MRI, CT scan, ultrasound) or oxygen-rich environments (hyperbaric chambers).
  • you should avoid sleeping or applying pressure on the prefilled automatic injection device.
  • you should avoid hot tubs, whirlpools, saunas, and direct sunlight.
  • you should avoid using lotions, oils, creams, and cleansers on your skin near the prefilled automatic injection device.

If the prefilled automatic injection device flashes red if the device comes off before the full dose is delivered, or if the adhesive on the device becomes wet or there is leaking, call your doctor right away. You may not have received the full dose of pegfilgrastim and may need an additional dose.

Dispose of used needles, syringes, and devices in a puncture-resistant container. Talk to your doctor or pharmacist about how to dispose of the puncture-resistant container.

What special precautions should I follow?

Before using pegfilgrastim injection products,

  • tell your doctor and pharmacist if you are allergic to pegfilgrastim, filgrastim (Granix, Neupogen, Nivestym, Releuko, Zarxio), any other medications, or any of the ingredients in pegfilgrastim injection products. Also tell your doctor if you or the person who will be injecting a pegfilgrastim injection product for you is allergic to latex, rubber, or acrylic adhesives.
  • tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
  • tell your doctor if you have or have ever had cancer of the blood or bone marrow, myelodysplasia (problems with bone marrow cells that may develop into leukemia), or kidney problems.
  • tell your doctor if you have sickle cell disease (a blood disease that may cause painful crises, a low number of red blood cells, infection, and damage to the internal organs). If you have sickle cell disease, you may be more likely to have a crisis during your treatment with a pegfilgrastim injection product. Call your doctor right away if you have a sickle cell crisis during your treatment.
  • tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while using a pegfilgrastim injection product, call your doctor.
  • you should know that pegfilgrastim injection products decrease the risk of infection but does not prevent all infections that may develop during or after chemotherapy. Call your doctor if you develop signs of infection such as fever; chills; rash; sore throat; diarrhea; or redness, swelling, or pain around a cut or sore.

Important information

Important information for patients receiving pegfilgrastim using the on-body injection (Neulasta Onpro kit).

  • See the Instructions for use for the on-body injector for detailed information about the on-body injector for Neulasta and important information about your dose delivery that has been written by your healthcare provider.
    • Know the time that delivery of your dose is expected to start.
    • Avoid traveling, driving, or operating heavy machinery during hour 26 through hour 29 after the on-body injector for Neulasta is applied. Avoid activities and places that may interfere with monitoring during the 45-minute period that the medication is expected to be delivered by the on-body injector, and for 1 hour after delivery.
  • A caregiver should be with you the first time that you receive this medication with the on-body injector.
  • Before your next scheduled dose, avoid use of lotions, creams, or oils on your arms and stomach area (abdomen) to help keep the device on your skin.
  • If placed on the back of the arm, a caregiver must be available to monitor the status of the on-body injector.
  • If you have an allergic reaction during the delivery of the medication, remove the on-body injector by grabbing the edge of the adhesive pad and peeling off the on-body injector. Get emergency medical help right away.
  • You should only receive a dose of the medication on the day your healthcare provider tells you.
  • You should not receive your dose any sooner than 24 hours after you finish receiving your chemotherapy. The on-body injector is programmed to deliver your dose about 27 hours after your healthcare provider places the on-body injector on your skin.
  • Do not expose the on-body injector to the following because it may be damaged and you could be injured:
    • Diagnostic imaging (e.g., CT Scan, MRI, Ultrasound, X-ray)
    • Radiation treatment
    • Oxygen rich environments, such as hyperbaric chambers
  • Avoid airport X-ray scans. Request a manual pat down instead. Use care during a manual pat down to help prevent the on-body injector from being accidentally removed.
  • Keep the on-body injector at least 4 inches away from electrical equipment such as cell phones, cordless telephones, microwaves and other common appliances. If the on-body injector is too close to electrical equipment, it may not work correctly and can lead to a missed or incomplete dose of your medication.
  • The on-body injector is for adult patients only.
  • If your on-body injector is not working properly, you may miss your dose or you may not receive your full dose. If you miss your dose or do not receive your full dose, you may have an increased risk of developing fever or infection.
  • Call your healthcare provider right away, as you may need a replacement dose, if any of the following occur:
    • on-body injector comes off before or during a dose delivery. Do not re-apply it.
    • on-body injector is leaking.
    • adhesive on your on-body injector becomes noticeably wet (saturated) with fluid, or there is dripping. This may mean that the medication is leaking out of your on-body injector. If this happens you may only receive some of your dose, or you may not receive a dose at all.
    • on-body injector status light is flashing red.

What should I avoid while using pegfilgrastim?

If you are receiving pegfilgrastim using an on-body injector, while the on-body injector is in place you should avoid:

  • traveling, driving or operating heavy machinery during hour 26 through hour 29 after the on-body injector is applied.
  • sleeping on the on-body injector or applying pressure on it. It may not work properly.
  • bumping the on-body injector or knocking it off your body.
  • using other materials to hold the on-body injector in place. Using other materials could cover audio or visual indicators or press the on-body injector against your skin, and lead to a missed dose or incomplete dose.
  • getting body lotion, creams, oils, and skin cleansing products near the on-body injector. These products may loosen the adhesive that holds the on-body injector onto your body.
  • using bath tubs, hot tubs, whirlpools, or saunas, and direct sunlight. These may affect your medication.
  • peeling off or disturbing the on-body injector adhesive before you receive your full dose.

References