Quantification of the cellular content of platelet-rich plasma harvested after injection of filgrastim versus pegfilgrastim biosimilars: a prospective, single-center, crossover study

Abstract

Introduction

Hematopoietic stem cells (HSCs) appear in peripheral blood (PB) following mobilization due to external events or pharmaceutical agents like filgrastim and pegfilgrastim. Concentration of these into platelet-rich plasma (PRP) can be used in orthopedics.

Objectives

This prospective, single-center, controlled laboratory study aimed to compare safety profiles of filgrastim and pegfilgrastim administration, quantifying the cellular content of PRP derived from PB post-administration. We hypothesized comparable rates and severity of adverse events (AEs) among participants, along with similar cellular content in the PRP products.

Methods

Ten healthy male participants underwent a crossover design with 2 interventions separated by a washout period. PB was collected before and after each intervention, producing PRP for cellular comparison in vitro. AEs were monitored for severity and frequency throughout study.

Results

Significant AEs for filgrastim included fatigue (36%), myalgia (36%), and back pain (9.1%), compared to pegfilgrastim, which included myalgia (31%), fatigue (23%), and back pain (23%). There were no significant differences between AE occurrences (P = .49) nor relationship to study drug (P > .99). Regarding total nucleated cell count (TNC), statistical significance was found in TNC count (P = .010) and TNC concentration (P = .004). All PRP products expressed high levels (>88%) of hematopoietic progenitor cell/HSC-specific CD45+, CD34+, CD45dim+, and hematopoietic progenitor cell/HSC+ markers.

Conclusions

This study demonstrated that filgrastim and pegfilgrastim administration appear safe. Pegfilgrastim is equivalent to filgrastim for the mobilization of white blood cells and cells expressing hematopoietic cell-surface markers into the PB and consequently, into the derived PRP product.

Clinical relevance

This study presents pegfilgrastim as a single-injection alternative to filgrastim for the mobilization of HSCs into the PB and subsequent PB-derived PRP, which is more convenient and less invasive for patients.