Pegfilgrastim

Pegfilgrastim (Neulasta brand and all biosimilars) is used to reduce the risk of infection (febrile neutropenia) in patients with non-myeloid malignancies receiving myelosuppressive anti-cancer drugs associated with a high risk of febrile neutropenia. The Neulasta, Udenyca, and Ziextenzo brands of pegfilgrastim are also FDA-approved to increase survival in patients acutely exposed to myelosuppressive doses of radiation (Hematopoietic Subsyndrome of Acute Radiation Syndrome).

• Pegfilgrastim is not approved for use in the mobilization of peripheral blood progenitor cells for hematopoietic stem cell transplantation.

Pegfilgrastim is a recombinant human granulocyte colony-stimulating factor (G-CSF) that stimulates your bone marrow to produce more white blood cells. It binds to receptors on immature blood cells (hematopoietic cells) and triggers them to develop into neutrophils, the infection-fighting cells needed during chemotherapy.

Pegfilgrastim is a pegylated form of G-CSF, which means it has a polyethylene glycol (PEG) molecule covalently bound to the N-terminus of filgrastim, which allows it to stay in your body for longer, meaning less frequent dosing compared to shorter-acting versions.

There are 8 biosimilars of pegfilgrastim available. Biosimilars are highly similar to Neulasta but not identical. Biosimilars of pegfilgrastim include:

• Ennumo (pegfilgrastim-pccg), approved in 2026
• Armlupeg (pegfilgrastim-unne), approved in 2025
• Fulphila (pegfilgrastim-jmbd), approved in 2018
• Fylnetra (pegfilgrastim-pbbk), approved in 2022
• Nyvepria (pegfilgrastim-apgf), approved in 2020
• Stimufend (pegfilgrastim-fpgk), approved in 2022
• Udenyca (pegfilgrastim-cbqv), approved in 2018
• Ziextenzo (pegfilgrastim-bmez), approved in 2019.

Neulasta and all of the biosimilar versions of pegfilgrastim are given by subcutaneous injection and supplied as a single-dose prefilled syringe (6 mg/0.6 mL). Some are also available as an autoinjector or in a single-dose vial.

• Neulasta Onpro and Undenyca Onpro are on-body injectors designed to release pegfilgrastim over approximately 45 minutes, starting approximately 27 hours after the device is applied to the skin.

Pegfilgrastim (Neulasta and all biosimilars) is FDA-approved 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 clinicallysignificant incidence of febrile neutropenia.

The Neulasta, Udenyca, and Ziextenzo brands of pegfilgrastim are also FDA-approved to:

• Increase survival in patients acutely exposed to myelosuppressive doses of radiation (Hematopoietic Subsyndrome of Acute Radiation Syndrome).

Pegfilgrastim is not approved for use in the mobilization of peripheral blood progenitor cells for hematopoietic stem cell transplantation.

The original brand of pegfilgrastim, Neulasta, was FDA-approved in 2002. Several biosimilar versions are available.

Single-dose prefilled syringe

• Pegfilgrastim is given as an injection under your skin (subcutaneous injection) by a healthcare provider. If your healthcare provider decides that the subcutaneous injections can be given at home by you or your caregiver, follow the detailed "Instructions for Use" that comes with your medication for information on how to prepare and inject a dose.
• You and your caregiver will be shown how to prepare and inject this medication before you use it.
• You should not inject a dose of pegfilgrastim into children weighing less than 45 kg from a prefilled syringe. A dose less than 0.6 mL (6 mg) cannot be accurately measured using the prefilled syringe.
• If you are receiving this medication because you are also receiving chemotherapy, the last dose of it should be injected at least 14 days before and 24 hours after your dose of chemotherapy.

Prefilled autoinjector

• Only adults can self-administer the Udenyca prefilled autoinjector.
• Ensure you receive training from your healthcare provider about how to administer the autoinjector. See the package instructions for detailed administration details.
• When a full dose has been administered, you will hear a second click and the orange indicator will completely block the viewing window.

On-body injector

The on-body injector is a wearable device that automatically delivers your pegfilgrastim dose (Neulasta Onpro or Udenyca Onbody) about 27 hours after your healthcare provider applies it to your skin.

How It Works

Your provider will apply the pre-filled device to your stomach or the back of your arm. The medication delivers over 45 minutes (Neulasta Onpro) or 5 minutes (Udenyca Onbody). You must be able to monitor the device during delivery and for 1 hour afterward.

You'll receive your dose at least 24 hours after finishing chemotherapy. Avoid driving or operating heavy machinery during hours 26-29 after application.

Monitoring Requirements

A caregiver should be present for your first dose.

• If placed on your arm, a caregiver must monitor the device
• Watch for the status light and check for leaks
• Keep the device dry for the last 3 hours before expected delivery

What to Avoid

Avoid traveling, driving, or operating heavy machinery during hours 26-29 after application.

Keep away from:

• Medical imaging (CT, MRI, X-ray, ultrasound)
• Radiation treatment
• Airport X-ray scanners (request manual pat-down instead)
• Electrical devices. Maintain a 4-inch distance from cell phones, microwaves, and appliances (device may malfunction, leading to missed or incomplete dose).

Environmental concerns:

• Only expose to temperatures between 41°F-104°F
• Avoid oxygen-rich environments like hyperbaric chambers
• Don't use lotions, creams, or oils on application areas before your dose
• Avoid bathtubs, hot tubs, whirlpools, saunas, and direct sunlight (may affect medication).

Avoid:

• Sleeping on the device or applying pressure to it
• Bumping or knocking the device off your body
• Using additional materials to secure it (may cover indicators or cause missed doses)
• Peeling off or disturbing the adhesive before receiving your full dose.

When to Call Your Doctor Immediately

Contact your provider if:

• The device falls off (don't reapply)
• You see leaking or dripping
• The adhesive becomes saturated with fluid
• The status light flashes red
• You may have received an incomplete dose.

Missing or receiving an incomplete dose increases your risk of fever or infection. You may need a replacement dose.

Note: This device is for adults only. See the Instructions for Use included with your device for complete details on monitoring, removal, and disposal.

Do not receive pegfilgrastim if you have had a serious allergic reaction to pegfilgrastim or filgrastim.

Before receiving this medication, tell your healthcare provider about all of your medical conditions, including if you:

• have a sickle cell disorder
• have kidney problems
• have had severe skin reactions to acrylic adhesives (if receiving the on-body injector)
• are allergic to latex and are receiving the Neulasta, Stimufend, or Ziextenzo brands of pegfilgrastim. The needle cap on the prefilled syringe for these brands contains dry natural rubber (derived from latex). You should not use these brands if you have a latex allergy.

The needle cap on the Ennumo prefilled syringe does contain dry natural rubber (derived from latex). People with latex allergies should not administer these products. The needle caps on the prefilled syringes for Fulphila, Fylnetra, Nyvepria, and Udenyca are not made with natural rubber latex.

Pregnancy

Tell your doctor if you are pregnant or plan to become pregnant. It is not known if pegfilgrastim will harm your unborn baby.

Breastfeeding

Tell your doctor if you are breastfeeding or plan to breastfeed. It is not known if pegfilgrastim passes into your breast milk.

Common Side Effects

The most common side effects of pegfilgrastim are:

• bone pain
• pain in your arms or legs.

Serious Side Effects and Warnings

Pegfilgrastim may cause the following serious side effects:

• Spleen rupture. Your spleen may become enlarged and can rupture. A ruptured spleen can cause death. Call your healthcare provider right away if you have pain in the left upper stomach area or your left shoulder.
• A serious lung problem called Acute Respiratory Distress Syndrome (ARDS). Call your healthcare provider or get emergency help right away if you have shortness of breath with or without a fever, trouble breathing, or a fast rate of breathing.
• Serious allergic reactions. Pegfilgrastim can cause serious allergic reactions. These reactions can cause a rash over your whole body, shortness of breath, wheezing, dizziness, swelling around your mouth or eyes, a fast heart rate, and sweating. If you have any of these symptoms, stop using pegfilgrastim and call your healthcare provider or get emergency medical help right away.
• Sickle cell crises. You may have a serious sickle cell crisis, which could lead to death, if you have a sickle cell disorder and receive pegfilgrastim. Call your healthcare provider right away if you have symptoms of a sickle cell crisis, such as pain or difficulty breathing.
• Kidney injury (glomerulonephritis). Pegfilgrastim can cause kidney injury. Call your healthcare provider right away if you develop any of the following symptoms: swelling of your face or ankles blood in your urine or dark colored urine urinating less frequently than usual.
• Increased white blood cell count (leukocytosis). Your healthcare provider will check your blood during treatment with pegfilgrastim.
• Decreased platelet counts (thrombocytopenia). Your healthcare provider will check your blood during treatment with pegfilgrastim. Tell your healthcare provider if you have unusual bleeding or bruising during treatment with pegfilgrastim. This could be a sign of decreased platelet counts, which may reduce the ability of your blood to clot.
• Capillary Leak Syndrome. Pegfilgrastim can cause fluid to leak from blood vessels into your body’s tissues. This condition is called “Capillary Leak Syndrome” (CLS). CLS can quickly cause you to have symptoms that may become life-threatening. Get emergency medical help right away if you develop any of the following symptoms: swelling or puffiness, and are urinating less than usual trouble breathing swelling of your stomach area (abdomen) and feeling of fullness dizziness or feeling faint a general feeling of tiredness.
• Myelodysplastic syndrome and acute myeloid leukemia. If you have breast cancer or lung cancer, when pegfilgrastim is used with chemotherapy and radiation therapy, or with radiation therapy alone, you may have an increased risk of developing a precancerous blood condition called myelodysplastic syndrome (MDS) or a blood cancer called acute myeloid leukemia (AML). Symptoms of MDS and AML may include tiredness, fever, and easy bruising or bleeding. Call your healthcare provider if you develop these symptoms during treatment with pegfilgrastim.
• Inflammation of the arteries (arteritis). Serious inflammation of the large and medium blood vessels that carry blood from your heart to the body, including the aorta (the largest artery), can happen in people receiving pegfilgrastim. Symptoms may include fever, stomach (abdominal) pain, back pain, headache, neck pain, or generally feeling unwell. Call your healthcare provider right away if you experience these symptoms.

This is not a complete list of side effects, and others may occur. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Dose of Pegfilgrastim for Patients with Cancer Receiving Myelosuppressive Chemotherapy

• Adults and children weighing 45 kg or more: 6 mg by subcutaneous injection once per chemotherapy cycle.
• Do not administer between 14 days before and 24 hours after administration of cytotoxic chemotherapy.
• Pediatrics: Use weight-based dosing for pediatric patients weighing less than 45 kg.

*For pediatric patients weighing less than 10 kg, administer 0.1 mg/kg (0.01 mL/kg) of pegfilgrastim

Dose of Pegfilgrastim (Neulasta and Udenyca brands) for Exposure to Myelosuppressive Doses of Radiation

• Adults: Two doses of pegfilgrastim 6 mg subcutaneously, one week apart. Administer the first dose as soon as possible after suspected or confirmed exposure to myelosuppressive doses of radiation, and a second dose one week after.
• Pediatrics: Use weight-based dosing for pediatric patients weighing less than 45 kg (see table above).

If you miss a dose of pegfilgrastim, talk to your healthcare provider about when you should give your next dose.

Tell your healthcare provider about all of the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.

The storage instructions for pegfilgrastim vary according to the brand you use. Refer to the manufacturer's prescribing information.

• Most prefilled syringes are stored in the refrigerator between 36°F to 46°F (2°C to 8°C).
• Do not freeze. If a prefilled syringe is accidentally frozen once, allow it to thaw in the refrigerator before using. If it is frozen more than once, throw it away and use a new syringe.
• Keep the prefilled syringe in the original carton to protect it from light or physical damage.
• Do not shake the prefilled syringe.
• Take it out of the refrigerator 30 minutes before use and allow it to reach room temperature.

Neulasta Ingredients

Active: pegfilgrastim

Inactive: acetate, polysorbate 20, sodium, and sorbitol in water for injection.

Ennumo Ingredients

Active: pegfilgrastim-pccg

Inactive: sorbitol, glacial acetic acid, sodium hydroxide, polysorbate 20, and water for injection.

Armlupeg Ingredients

Active: pegfilgrastim-unne

Inactive: sorbitol, glacial acetic acid, sodium acetate trihydrate, polysorbate 20, and water for injection.

Fulphila Ingredients

Active: pegfilgrastim-jmbd

Inactive: acetate, D-sorbitol, polysorbate 20, and sodium in water for Injection.

Fylnetra Ingredients

Active: pegfilgratim-pbbk

Inactive: acetic acid, polysorbate 20, sodium hydroxide, and sorbitol in water for injection.

Nyvepria Ingredients

Active: pegfilgrastim-apgf

Inactive: acetate, polysorbate 20, sodium, and sorbitol in water for injection.

Stimufend Ingredients

Active: pegfilgrastim-fpgk

Inactive: acetate, polysorbate 20, sodium, and sorbitol in water for injection, USP.

Udenyca Ingredients

Active: pegfilgrastim-cbqv

Inactive: acetate, polysorbate 20, sodium, and sorbitol in water for injection.

Ziextenzo Ingredients

Active: pegfilgrastim-bmez

Inactive: acetic acid, polysorbate 20, sorbitol, and water for Injection. Sodium hydroxide may be added as necessary to adjust pH.

Nuelasta: Amgen Inc.

Ennumo: Accord BioPharma Inc.

Armlupeg: Lupin Limited

Fulphila: Mylan Pharmaceuticals Inc.

Fylnetra: Kashiv BioSciences, LLC.

Nyvepria: Hospira, Inc.

Stimufend: Fresenius Kabi USA, LLC.

Udenyca: Coherus BioSciences, Inc.

Ziextenzo: Sandoz Inc.

Biosimilar and interchangeable products are biological products that are highly similar to and have no clinically meaningful differences from the reference product.

Reference products

These are biological products that have already been approved by the FDA, against which biosimilar products are compared. There are 2 for pegfilgrastim.

Neulasta (pegfilgrastim) - Amgen Inc.

View Neulasta information in detail.

Neulasta Onpro (pegfilgrastim) - Amgen Inc.

View Neulasta Onpro information in detail.

Neulasta, Neulasta Onpro biosimilar products

Biosimilar products can only be dispensed in place of the reference product if the healthcare provider specifically prescribes the biosimilar product by name.

Pharmacy laws for biosimilar prescribing may vary by state

Armlupeg (pegfilgrastim-unne) - Lupin Limited (Biotech Division)

View Armlupeg information in detail.

Ennumo (pegfilgrastim-pccg) - Accord BioPharma Inc.

Ennumo

Fulphila (pegfilgrastim-jmdb) - Biocon Biologics Inc.

View Fulphila information in detail.

Fylnetra (pegfilgrastim-pbbk) - Kashiv BioSciences, LLC

View Fylnetra information in detail.

Nyvepria (pegfilgrastim-apgf) - Hospira Inc., a Pfizer Company

View Nyvepria information in detail.

Stimufend (pegfilgrastim-fpgk) - Fresenius Kabi USA, LLC

View Stimufend information in detail.

Udenyca (pegfilgrastim-cbqv) - Accord BioPharma Inc.

View Udenyca information in detail.

Udenyca Onbody (pegfilgrastim-cbqv) - Accord BioPharma Inc.

View Udenyca Onbody information in detail.

Ziextenzo (pegfilgrastim-bmez) - Sandoz Inc.

View Ziextenzo information in detail.