A key advisory committee of the US Food and Drug Administration (FDA) has voted in favour of licencing a copycat version of a biological drug. If approved, Sandoz’s Zarxio (filgrastim) would be the first ‘biosimilar’ drug available in the US.
On 7 January, the FDA’s Oncological Drugs Advisory Committee unanimously cleared Sandoz’ version of filgrastim – marketed as Neupogen by Amgen – for all five indications approved for the Amgen drug. The medication is used to prevent infection and low white blood cell counts caused by chemotherapy.
|Systematic (IUPAC) name|
|Human granulocyte colony stimulating factor|
|Molecular mass||18802.8 g/mol|
Filgrastim is a granulocyte colony-stimulating factor (G-CSF) analog used to stimulate the proliferation and differentiation ofgranulocytes; it is a pharmaceutical analog of naturally occurring G-CSF. It is produced by recombinant DNA technology. The gene for human granulocyte colony-stimulating factor is inserted into the genetic material of Escherichia coli. The G-CSF then produced byE. coli is different from G-CSF naturally made in humans.
Filgrastim is marketed under several brand names, including:
|Dr. Reddy’s Laboratories||Grafeel|
|Reliance Life Sciences||Religrast|
Apricus Biosciences is currently developing and testing a product under the brand name Nupen which can deliver filgrastim through the skin to improve post-chemotherapy recovery of neutrophil counts.
Mechanism of Action: Filgrastim is a human granulocyte colony stimulating factor (G-CSF) produced by recombinant DNA technology. G-CSF regulates the production of neutrophils within the bone marrow; endogenous G-CSF is a glycoprotein produced by monocytes, fibroblasts, and endothelial cells.
G-CSF is a colony stimulating factor which has been shown to have minimal direct in vivo or in vitro effects on the production of other haematopoietic cell types.NEUPOGEN (filgrastim) is the name for recombinant methionyl human granulocyte colony stimulating factor (r-metHuG-CSF). ref: 
Filgrastim should not be used in patients with known hypersensitivity to E. coli-derived proteins.
The most commonly observed adverse effect is mild-to-moderate bone pain after repeated administration and local skin reactions at the site of injection. Other observed adverse effects include serious allergic reactions (including a rash over the whole body, shortness of breath, wheezing, dizziness, swelling around the mouth or eyes, fast pulse, and sweating), ruptured spleen (sometimes resulting in death), alveolar hemorrhage, acute respiratory distress syndrome, and hemoptysis. Severe sickle cell crises, in some cases resulting in death, have been associated with the use of filgrastim in patients with sickle cell disorders.
Drug interactions between filgrastim and other drugs have not been fully evaluated. Drugs which may potentiate the release of neutrophils‚ such as lithium‚ should be used with caution.
Increased hematopoietic activity of the bone marrow in response to growth factor therapy has been associated with transient positive bone imaging changes; this should be considered when interpreting bone-imaging results.
Filgrastim has not been studied in pregnant women and its effects on the foetus is unknown. If taking filgrastim while pregnant, it is possible that traces of the drug could be found in the baby’s blood. It is not known if the drug can get into human breast milk.
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- “FDA Reviews What Could Be First Biosimilar”. Discov. Dev. Mag. (Rockaway, New Jersey, United States). Associated Press. 25 July 2014.
- Crawford, J.; Glaspy, J. A.; Stoller, R. G.; Tomita, D. K.; Vincent, M. E.; McGuire, B. W.; Ozer, H. (2005). “Final Results of a Placebo-Controlled Study of Filgrastim in Small-Cell Lung Cancer: Exploration of Risk Factors for Febrile Neutropenia”. Supportive Cancer Therapy 3 (1): 36–46. doi:10.3816/SCT.2005.n.023. PMID 18632435.
- Neupogen “Neupogen: Patient Information Leaflet”. Amgen. Retrieved 24 June 2013.
- “NEUPOGEN® Patient Guide”. Amgen. Retrieved 24 June 2013.
- “Neupogen”. RxList. 4 June 2012. Retrieved 23 June 2013.