What Is Neupogen and What Does It Do?
Neupogen (filgrastim) is a recombinant human granulocyte colony-stimulating factor (G-CSF) used to stimulate the production and maturation of neutrophils, a type of white blood cell.[1] Neutrophils are key immune cells that fight bacterial infections.
How Does Neupogen Work on Cells?
It binds to G-CSF receptors on hematopoietic progenitor cells in the bone marrow, triggering signaling pathways that promote cell proliferation, differentiation, and survival. This increases neutrophil counts in the blood, typically within 24-48 hours of administration.[1][2]
Common Uses for Neutrophil Support
- Reduces neutropenia risk after chemotherapy.
- Mobilizes hematopoietic stem cells for transplants.
- Treats severe chronic neutropenia.[1]
Who Makes Neupogen and Patent Status?
Amgen developed and manufactures Neupogen. U.S. patents have largely expired, allowing biosimilars like Zarxio (2015) and Nivestym (2018) to enter the market.3
Side Effects Involving Cells or Blood
Common: Bone pain from rapid cell production. Rare: Splenic rupture, acute respiratory distress, or allergic reactions.[1]
Biosimilars and Alternatives
| Product | Manufacturer | Approval Year (FDA) |
|---------|--------------|---------------------|
| Zarxio (filgrastim-sndz) | Sandoz | 2015 |
| Nivestym (filgrastim-aafi) | Pfizer | 2018 |
| Udenyca (pegfilgrastim-cbqv) | Coherus (longer-acting) | 2018 |
These compete on price while matching efficacy.3
[1]: https://www.neupogen.com/
[2]: https://www.accessdata.fda.gov/drugsatfda_docs/label/2015/103353s5149lbl.pdf