Abnormally low neutrophil counts can occur secondary to myelosuppression, which increases the risk of serious infection during chemotherapy, resulting in a longer course of therapy or lower, less effective dosages.
Fever accompanying low neutrophil counts, known as febrile neutropenia, can increase the severity of such chemotherapy-related infections. Pegfilgrastim (Neulasta) has been shown to decrease the time the body needs to replenish neutrophil levels, thereby reducing the risk of infection. A new agent, pegfilgrastim-jmdb (Fulphila), is the first pegfilgrastim biosimilar to be approved to decrease the chance of infection in patients with nonmyeloid (non-bone marrow) cancer who are receiving myelosuppressive chemotherapy. Pegfilgrastim-jmdb is not indicated for use before hematopoietic stem cell transplantation.
Biosimilar drugs are similar enough to approved biologic drugs-those derived from living organisms, such as animals (including humans), microorganisms, or yeast-to have no clinically meaningful differences in terms of safety and effectiveness from the reference biologic, also known as the parent drug.
Pegfilgrastim-jmdb has been shown to be highly similar to pegfilgrastim, although they are not considered interchangeable. Interchangeable products have met additional requirements proving that they produce the same clinical results as the original product and can be substituted for the original product without consulting the prescriber.
The first neutrophil stimulant drug, filgrastim (Neupogen), and derivative products are colony-stimulating factors that stimulate specific cell-surface receptors of immature blood stem cells (hematopoietic stem cells), which develop into all blood cell types. Stimulation by filgrastim, pegfilgrastim, and pegfilgrastim-jmdb promotes proliferation and differentiation of neutrophils.
The addition of polyethylene glycol to the chemical structure of filgrastim doubles the size of the molecule, reducing renal clearance and creating a longer half-life. Consequently, pegfilgrastim products need not be administered as frequently.
The most common adverse effects of pegfilgrastim-jmdb are the same as those of pegfilgrastim: bone pain and pain in the extremities. Both drugs carry warnings of possible serious adverse effects: spleen rupture; acute respiratory distress syndrome; serious allergic reactions, including anaphylaxis; glomerulonephritis; leukocytosis; capillary leak syndrome; tumor growth; and severe sickle cell crises.
Nurses should understand that pegfilgrastim-jmdb cannot automatically be substituted for pegfilgrastim. Like pegfilgrastim, pegfilgrastim-jmdb is administered as a subcutaneous injection after every chemo-therapy cycle using a single-dose prefilled syringe. Nurses should provide education on the potential for serious adverse effects and the signs and symptoms that should be reported immediately. Patients who are to receive pegfilgrastim-jmdb at home should be taught how to inject the medication. They should also be made aware that they can find the instructions and lists of possible adverse effects in the drug's labeling. To see the full prescribing information for pegfilgrastim-jmdb, see http://www.accessdata.fda.gov/drugsatfda_docs/label/2018/761075s000lbl.pdf.