Fylnetra is administered as a single subcutaneous (under the skin) injection once per chemotherapy cycle. It comes in a prefilled syringe for manual use.

• Administration: A healthcare professional will typically administer the injection in a clinic setting. In some cases, patients or their caregivers may be trained to give the injection at home.
• Timing: The injection should be given at least 24 hours after you complete your chemotherapy, and no less than 14 days before your next planned chemotherapy dose. Precise timing is crucial.
• Injection Sites: Common injection sites include the upper arm, thigh, or abdomen. It’s important to rotate injection sites if you are giving repeated injections to avoid local skin reactions.
• Preparation: Allow the prefilled syringe to reach room temperature for at least 30 minutes before injecting. Do not shake the syringe. Inspect the solution for discoloration or particles before use; if present, do not use.
• Storage: Store Fylnetra in the refrigerator (2°C to 8°C). Do not freeze.

Always follow your healthcare provider’s specific instructions for preparation and injection.

Fylnetra works by stimulating the production and release of neutrophils, a type of white blood cell, from your bone marrow. Neutrophils are a vital part of your immune system, acting as the “first responders” to fight bacterial and fungal infections. The active ingredient, pegfilgrastim-pbbk, is a modified form of a natural protein called Granulocyte Colony-Stimulating Factor (G-CSF). When chemotherapy reduces your neutrophil count, Fylnetra signals your bone marrow to produce more of these infection-fighting cells. The “pegylated” part of pegfilgrastim means it’s attached to a polyethylene glycol molecule, which makes it last longer in your body compared to regular G-CSF, allowing for a single dose per chemotherapy cycle. By increasing neutrophil counts, Fylnetra helps to reduce your risk of developing serious infections that can lead to hospitalization or treatment delays.

• Fylnetra stimulates bone marrow to produce neutrophils.
• Neutrophils are crucial white blood cells that fight infection.
• Active ingredient (pegfilgrastim-pbbk) is a long-acting form of G-CSF.
• It signals bone marrow to create more infection-fighting cells.
• This reduces the risk of serious infections and chemotherapy delays.

Like all medications, Fylnetra can cause side effects. Your doctor will monitor you closely for these. Common side effects often include:

• Bone pain: This is the most common side effect, often felt in the long bones (arms, legs) or back. It can usually be managed with over-the-counter pain relievers like acetaminophen or ibuprofen.
• Pain in arms or legs.
• Injection site reactions: Redness, pain, itching, or bruising at the injection site.
• Nausea.
• Headache.

More serious, but less common, side effects require immediate medical attention:

• Splenic Rupture: Though rare, the spleen can enlarge and rupture, causing severe pain in the upper left abdomen or left shoulder. This can be fatal.
• Acute Respiratory Distress Syndrome (ARDS): Characterized by fever, difficulty breathing, or lung problems.
• Serious Allergic Reactions (Anaphylaxis): Including rash, hives, swelling of the face/throat, difficulty breathing, or rapid heartbeat.
• Sickle Cell Crisis: In patients with sickle cell disorder, Fylnetra can trigger severe and sometimes fatal sickle cell crises.
• Glomerulonephritis: A type of kidney inflammation.
• Capillary Leak Syndrome: Fluid leakage from small blood vessels, causing swelling, low blood pressure, and decreased urination.

Myelodysplastic Syndrome (MDS) and Acute Myeloid Leukemia (AML): In rare cases, especially with long-term use in certain cancer types, there’s a theoretical risk of developing these blood disorders.

Before taking Fylnetra, it’s important to be aware of several warnings and precautions:

• Splenic Rupture: Report any severe left upper abdominal or left shoulder pain immediately.
• Acute Respiratory Distress Syndrome (ARDS): Seek immediate medical attention for any new or worsening fever, cough, or difficulty breathing.
• Allergic Reactions: Do not use Fylnetra if you have a history of serious allergic reactions to pegfilgrastim or filgrastim products. Be aware of signs of allergic reactions (rash, swelling, trouble breathing) and seek emergency help if they occur.
• Sickle Cell Disorder: Patients with sickle cell trait or disease are at increased risk of sickle cell crisis; Fylnetra should be used with extreme caution or avoided in these patients.
• Kidney Problems: Fylnetra use in patients with kidney impairment should be carefully monitored.
• Leukocytosis: Your white blood cell counts will be monitored regularly, as very high counts can occur.
• Myelodysplastic Syndrome (MDS) and Acute Myeloid Leukemia (AML): Discuss with your doctor if you have breast or lung cancer, as there’s a very small, theoretical increased risk when used with chemotherapy/radiotherapy.
• Aortitis: A rare inflammation of the aorta has been reported.
• Pregnancy and Breastfeeding: Discuss with your doctor. It’s unclear if Fylnetra can harm an unborn baby or pass into breast milk.
• Do not use for Peripheral Blood Progenitor Cell Mobilization: Fylnetra is not indicated for collecting stem cells for transplantation.

Fylnetra has a relatively low risk of direct drug-to-drug interactions with most chemotherapy agents. However, there are important considerations regarding its timing with chemotherapy:

• Timing with Chemotherapy: It is crucial NOT to administer Fylnetra between 14 days before and 24 hours after cytotoxic chemotherapy. Giving it too soon after chemotherapy can potentially worsen myelosuppression, and giving it too close before may interfere with chemotherapy’s action. Your doctor will carefully schedule the injection.
• Lithium: Although rare, some G-CSF products might interact with lithium, leading to increased white blood cell counts.
• Other Myelosuppressive Agents: Fylnetra is used to counteract myelosuppression, but your doctor will be aware of other drugs that might also affect blood counts.
• Certain imaging agents: Fylnetra can cause changes in bone imaging tests, potentially leading to false results. Inform imaging personnel that you are receiving Fylnetra.

Always provide your full medication list, including over-the-counter drugs, herbal supplements, and vitamins, to your doctor or pharmacist to ensure safe treatment.

The standard dosage of Fylnetra for most adult and pediatric patients (weighing 45 kg or more) receiving myelosuppressive chemotherapy is a single 6 mg dose, administered via subcutaneous injection once per chemotherapy cycle.

• Timing: Administer at least 24 hours after the completion of chemotherapy. Do not administer within 14 days before the start of the next planned chemotherapy dose.
• Pediatric Patients (weighing less than 45 kg): The dose is weight-based:
  • Less than 10 kg: 0.1 mg/kg (0.01 mL/kg)
  • 10 to 20 kg: 1.5 mg
  • 21 to 30 kg: 2.5 mg
  • 31 to 44 kg: 4 mg
  • Note: The prefilled syringe is designed for 6 mg and may not allow accurate measurement of smaller pediatric doses; specific instructions for drawing up smaller volumes might be provided.
• Acute Radiation Syndrome: For patients acutely exposed to myelosuppressive doses of radiation, two doses of 6 mg, administered one week apart, may be recommended, with the first dose as soon as possible after exposure.

Your doctor will determine the exact timing and dosage based on your chemotherapy schedule and individual needs.

Fylnetra is a prescription-only medication (POM). It is not available over-the-counter. Due to its specialized use in managing chemotherapy side effects and the potential for serious side effects, Fylnetra must be prescribed by a licensed medical doctor, typically an oncologist or hematologist. Before prescribing, your doctor will assess your type of cancer, chemotherapy regimen, and overall health. Throughout your treatment with Fylnetra, you will undergo regular blood tests (complete blood counts) to monitor your white blood cell levels and ensure the medication is working safely and effectively. Fylnetra can be obtained from pharmacies in Pakistan, but only with a valid prescription.

• Fylnetra is a prescription-only medication (POM).
• Not available over-the-counter.
• Requires a valid prescription from a licensed medical doctor, usually an oncologist.
• Requires careful assessment of cancer type and chemotherapy regimen.
• Ongoing monitoring with regular blood tests is essential.

What is Fylnetra used for? To decrease the incidence of infection (febrile neutropenia) in patients with non-myeloid malignancies receiving myelosuppressive chemotherapy

2. What is the active ingredient? Pegfilgrastim-pbbk

3. What drug class does it belong to? Granulocyte colony-stimulating factor (G-CSF)

4. Is Fylnetra a controlled substance? No

5. Is Fylnetra available in generic form? It is a biosimilar to Neulasta

6. How is Fylnetra administered? Subcutaneous injection

7. What strengths are available? 6 mg/0.6 mL prefilled syringe

8. What is the usual adult dosage? Single 6 mg injection per chemotherapy cycle, at least 24 hours after chemo

9. Can it be used in children? Safety and efficacy not established in pediatric patients

10. What are common side effects? Bone pain, headache, fatigue, injection site reactions

11. Can it cause serious reactions? Yes—splenic rupture, ARDS, allergic reactions

12. Is Fylnetra safe during pregnancy? Limited data; use only if benefits outweigh risks

13. Is a prescription required? Yes

14. Is Fylnetra available in Pakistan? Not widely; may be accessed via oncology specialty import programs

15. How should it be stored? Refrigerated at 2–8°C; protect from light; do not freeze

16. What precautions should be taken during use? Monitor for splenic enlargement, respiratory symptoms, allergic reactions

17. What are contraindications? Hypersensitivity to pegfilgrastim or filgrastim products

18. What monitoring is needed during use? CBC with differential, signs of infection, spleen size

19. Can Fylnetra be combined with chemotherapy? Yes—given after chemo, not during or immediately before

20. What are similar drugs? Neulasta, Fulphila, Ziextenzo, Udenyca