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

ABSTRACT

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.

KEYWORDS:

• Immunogenicity
• ADA
• NAB
• neutralizing antibody assay
• biosimilar
• pegfilgrastim
• validation

Funding

This paper was not funded.

Data availability statement

The data presented in this publication is available with Lambda Therapeutic Research and will be available on request.

Acknowledgments

We gratefully acknowledge contributions of Dr. Vinu Jose who was the Study Director for the study design, and Dr. Anshul Attrey for conducting the study at Lambda Therapeutics Research as Principal Investigator. The contributions of Ms. Megha Barot, Ms. Bhoomika Bhatt, Mr. Gaurang Vekariya, and Ms. Shalaka Gosavi are gratefully acknowledged for development and validation of ADA and NAb assays and for analysis of clinical immunogenicity samples. We thank all present and previous members of Bioanalytical (Biosimilars) team for their support.

Author contributions

All immunogenicity assays were designed by P Hajela, with guidance from P Kale and S Khambhampaty. The assays were conducted at Bioanalytical (Biosimilars) laboratory of Lambda Therapeutic Research under supervision of P Hajela. The statistical analysis was done under supervision of R Patel at Lambda Therapeutic Research. M Kumar and S Khambhampaty were responsible for review of design and data interpretation. P Hajela authored and reviewed the paper. S Khambhampaty conceptualized the paper, participated in authoring and reviewing. All authors agree to be accountable for all aspects of the work.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial relationships or otherwise to disclose.

Declaration of interests

The authors are employees of Intas Pharmaceuticals (S Khambhampaty and M Kumar) or Lambda Therapeutic Research (P Hajela, R Patel, P Kale). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.