Bone Marrow Transplantation | 2019
Does use of biosimilar G-CSF change plerixafor utilization during stem cell mobilization for autologous stem cell transplant?
Abstract
Autologous hematopoietic stem cell transplantation (aHSCT) is an integral part of the management of several hematologic malignancies. Candidates for aHSCT need to undergo stem cell mobilization. Cytokine mobilization involves the administration of growth factors such as granulocyte colony stimulating factor (G-CSF). Chemomobilization involves the use of chemotherapy followed by cytokines. Recombinant G-CSF analog, Filgrastrim (Neupogen®) is the most commonly used myeloid growth factor for mobilization. Recently, many biosimilar agents were introduced. Biosimilars are agents that display biologic similarity with their FDA approved biologic counterparts [1]. Unlike generics, they are not identical to their reference product [2]. Zarxio® was the first biosimilar drug to gain FDA approval in 2015 [3]. With traditional mobilization strategies, a subset of patients fail to mobilize an adequate number of stem cells for transplant. Plerixafor is a reversible antagonist of chemokine receptor type 4 (CXCR4), which has been shown to increase stem cell yield when combined with G-CSF, and has been approved for use in patients with multiple myeloma (MM) and non-Hodgkin’s lymphoma (NHL) [4–7]. It can be used upfront, but is more commonly used in a preemptive manner where it is added to Filgrastrim in patients who are expected to mobilize poorly based on the pre-apheresis peripheral blood CD34+ cell count or low yield on the first day of collection [8, 9]. This approach has been shown to increase stem cell yield, decrease days of mobilization and apheresis, and decrease mobilization failure rate [8, 9]. At our institution, formulary was switched from Neupogen® to Zarxio® in April 2016. Our institutional practice is to use Plerixafor in patients who, on the first planned day of mobilization, have a peripheral CD 34+ve cell count <20/uL. This approach prevents unnecessary plerixafor use and reduces healthcare costs. Although studies have shown that Zarxio® displays similar efficacy in stem cell mobilization compared to the original G-CSF [10–12], the effect on use of additional mobilization agents like plerixafor has not been well studied. Therefore, we conducted this analysis to evaluate the association between the type of G-CSF used for mobilization and plerixafor utilization. We performed a retrospective chart review utilizing the blood and marrow transplantation database at the Karmanos Cancer Institute. The study included patients with hematologic malignancies, ≥18 years, who underwent stem cell mobilization for aHSCT between January 2015 and June 2017. Collected data included age, weight, gender, race, diagnosis, disease status at the time of mobilization, lines of treatment and radiation therapy prior to mobilization, WBC count, platelet count and hemoglobin prior to collection, type of G-CSF used for mobilization, peripheral CD34+ ve cell count on the first planned day of collection, whether apheresis was performed on the first planned day of collection, volume of blood processed on the first planned day of collection, total number and volume of CD34+ ve cells/ kg collected, plerixafor use on the first planned day of collection, need for a second mobilization attempt and total number of days of apheresis. For patients who underwent transplant, data were collected on engraftment, and duration of hospitalization. Per our institutional policy, patients received G-CSF 10 μg/kg for 5 days and received plerixafor if peripheral CD34+ ve cell count (flow cytometry on peripheral blood) on the first planned day of collection was <20/uL. The target CD34+ ve stem cell dose for aHSCT * Abhinav Deol [email protected]