Pegfilgrastim Biosimilars: Where Are We Now?

In 1991, the U.S. Food & Drug Administration (FDA) approved rmetHuG-CSF for human use. This recombinant methionyl human granulocyte colony-stimulating factor, or filgrastim, saw use in over 1 million patients in its first 5 years on the market. In 2002, the FDA approved a version of filgrastim with covalent linkage to a monomethoxypolyethylene glycol, increasing the molecular size and half-life to replace multiple days of dosing with a single injection. These medications remained standard of care for neutropenia until the Biologics Price Competition and Innovation Act of 2009 created an abbreviated pathway to licensure for biologic products. Practitioners now have their pick of numerous and expanding options for pegfilgrastim biosimilars.

Clinical Characteristics of Intravenous PEG-Asparaginase Hypersensitivity Reactions in Patients Undergoing Treatment for Acute Lymphoblastic Leukemia

Background: Asparaginase poses a substantial risk for hypersensitivity reactions during and after administration; however, these reactions vary by asparaginase formulation and administration route. It is imperative that nurses be knowledgeable of clinical symptoms associated with intravenous (IV) monomethoxypolyethylene glycol (PEG)-asparaginase reactions, as well as potential reaction timing. Purpose: This single institution retrospective study describes the clinical factors among patients with IV PEG-asparaginase hypersensitivity reactions. Methods: Reaction frequency and severity, dose, phase of treatment, and time between infusion initiation and reaction were collected on patients identified as having an IV PEG-asparaginase hypersensitivity reaction while undergoing acute lymphoblastic leukemia treatment. Results: Sixty-three patients (12.8%) developed a hypersensitivity reaction to IV PEG-asparaginase, with the reaction occurring during a median of 3 doses in both risk arms. Reactions were noted ≤60 minutes after infusion initiation in 98% of patients, and no reactions were fatal. Conclusion: Nurses should carefully observe patients throughout the infusion and anticipate adverse reactions, particularly during the first 3 doses and first 10 minutes of each infusion. Patient and family education should include the rare risk of delayed reactions.