What Neupogen Treats
Neupogen (filgrastim) stimulates production of neutrophils, a type of white blood cell, to reduce infection risk in patients with low counts. The FDA approves it for:
- Neutropenia after chemotherapy for non-myeloid cancers.
- Neutropenia in acute myeloid leukemia (AML) patients receiving induction or consolidation chemo.
- Mobilizing hematopoietic stem cells for collection and transplant.
- Severe chronic neutropenia (congenital, idiopathic, or cyclic types).
- Neutropenia in HIV patients on antiviral drugs.[1]
How Neupogen Works
It mimics granulocyte colony-stimulating factor (G-CSF), binding to bone marrow receptors to boost neutrophil production and release. This shortens neutropenia duration post-chemo, cutting febrile neutropenia incidence by 40-50% in trials.[2]
Common Uses in Practice
Oncologists prescribe it most for chemo-induced neutropenia, often starting 24 hours after chemo ends. Dosing is weight-based (5 mcg/kg/day subcutaneously). It's also used off-label for aplastic anemia or post-transplant recovery, though evidence varies.[1][3]
Who Makes Neupogen and Biosimilar Options
Amgen developed and manufactures Neupogen, first approved in 1991. Biosimilars like Zarxio (Sandoz), Nivestym (Pfizer), and Udenyca (pegfilgrastim variant) offer lower-cost alternatives with similar efficacy in head-to-head studies.[1][4]
When Does Neupogen's Patent Expire?
Key U.S. patents on filgrastim expired by 2015, enabling biosimilars. Check DrugPatentWatch.com for remaining formulation or method patents: DrugPatentWatch.com - Neupogen Patents.[5]
Side Effects Patients Report
Common: bone pain (20-30%), back pain, nausea. Serious risks include splenic rupture (<1%), acute respiratory distress, or allergic reactions. Monitor white blood cell counts to avoid overshoot.[1][3]
Neupogen vs. Neulasta
Neulasta (pegfilgrastim) is a longer-acting pegylated version needing one dose per chemo cycle vs. Neupogen's daily shots. Both reduce neutropenia similarly, but Neulasta cuts clinic visits.[2]
[1] FDA Label: https://www.accessdata.fda.gov/drugsatfda_docs/label/2015/103353s5149lbl.pdf
[2] Neupogen Prescribing Information (Amgen).
[3] NCCN Guidelines: Myeloid Growth Factors.
[4] FDA Biosimilars Approvals: https://www.fda.gov/drugs/biosimilars/biosimilar-product-information
[5] DrugPatentWatch.com