Single-Dose Pharmacokinetics, Pharmacodynamics and Immunogenicity, and Multiple-Dose Immunogenicity of INTP5 (Pegfilgrastim Biosimilar) Versus Reference Pegfilgrastim in Healthy Subjects

Achieving white blood cell equity: are the safety profiles of biosimilar and reference pegfilgrastims comparable?

Biosimilars can provide choices for patients and may provide cost savings; however, their uptake has been slow in the USA, in part due to limited knowledge. To provide additional confidence in US pegfilgrastim biosimilars, this narrative review compared the safety profiles of biosimilar pegfilgrastims, currently approved or filed for approval in the USA, with the EU- and US-approved reference pegfilgrastims. Headache and bone pain were common to biosimilars and reference products and occurred at a similar incidence. Clinical trial data on the safety profiles of biosimilar pegfilgrastims and reference products have demonstrated similarity and comparability, with no unexpected safety outcomes. Overall, the safety profiles of biosimilar pegfilgrastims and reference pegfilgrastims demonstrated a high degree of similarity and comparability.

A review of bridging clinical studies between different presentations of biological products approved by the United States Food and Drug Administration (US FDA)

INTRODUCTION

There is growing interest in the development of multiple presentations for biological products for subcutaneous (SC) injection for life cycle management and product differentiation. Bridging clinical studies are required to extrapolate the existing data package to new presentations.

AREAS COVERED

This review compiles information of bridging clinical studies conducted for biological products administered by the SC route and approved in more than one presentation by the United States Food and Drug Administration's Center for Drug Evaluation and Research up until 31 December 2021. Information regarding indication(s), presentation(s), approval pathways, approval timelines, and various aspects of bridging clinical studies was collected from published documents.

EXPERT OPINION

The type of bridging clinical study can depend on the extent of differences between presentations, existing data packages, and the stage of the product development. Design of a bridging clinical study should be based on the characteristics of a biological product and should be aimed at detecting the relevant differences between presentations. Single-dose comparative pharmacokinetics in normal healthy volunteers is the most common bridging clinical study design. Covariates like body weight and injection site should be considered during the design of these studies. The impact of the different user interfaces of presentations should also be considered.

[Anti-cytokine autoantibodies: Review of the literature]

Anti-cytokine antibodies (ACA) are an emerging cause of acquired immunodeficiency, especially in previously healthy adults. The most frequently reported are anti-IFN-γ responsible for disseminated non-tuberculous mycobacteria infections, and anti-GM-CSF mainly in mycobacteria, cryptococcosis and nocardiosis infections. The presence of anti-IFN-α in severe COVID-19 infections has recently been described. The search for and detection of these ACAs in an unusual infection situation makes it possible to set up specific therapies in addition to the anti-infective treatment. ACAs are also frequent in various autoimmune pathologies where, in addition to being indicators of the breakdown of immune tolerance, they can modulate the activity of the disease according to their cytokine target. In this review of the literature, we will focus on the epidemiology and the clinical impact of these ACAs in healthy subjects and in infectious or dysimmune diseases.

A comparative multi-tiered immunogenicity assessment of biosimilar pegylated filgrastim: validation of methods for clinical assessment of INTP5

BACKGROUND AND OBJECTIVE

Validated and highly sensitive assays are required for comparative assessment of immunogenicity of biosimilars. For INTP5, a biosimilar pegylated filgrastim, the immunogenicity assessment included tiers that allowed for assessment of antibodies against the PEG and the Filgrastim moieties for comparative clinical immunogenicity assessment.

METHODS

Electrochemiluminescence immunoassay (ECLIA) was used for Screening, Specificity, and Titer assays for detecting anti-drug antibodies (ADAs) and cell-based method for neutralizing ADAs. The methods were validated to enable use of same methods irrespective of biosimilar or reference arms.

RESULTS

The ADA and cell-based assay for neutralizing antibody detection were validated with a sensitivity capable of detecting binding Anti-Pegfilgrastim antibody at ~40 ng/mL and Neutralizing antibody at ~380 ng/mL and used for a comparative immunogenicity study. Of 194 subjects, 10 subjects had confirmed positive anti-drug-antibody in the biosimilar arm and 9 in the reference arm. None of the subjects were detected with neutralizing anti-drug antibodies.

CONCLUSION

This work demonstrates the application of a rigorous approach toward validation of assays for immunogenicity studies for biosimilars. Highly sensitive, precise, and robust assays were used to conclude comparable low incidences of anti-drug antibodies in both biosimilar and innovator arms of the clinical study for Pegfilgrastim.