Determination Method Validation of Bioactivity of Adalimumab Monoclonal Antibody by Apoptosis Assay

Abstract

Background: Adalimumab is an immunosuppressive drug that works by blocking tumor necrosis factor-alpha, commonly used to treat autoimmune inflammatory diseases. The structure of adalimumab is a fully human recombinant immunoglobulin G1 (IgG1) monoclonal antibody that represents significant specificity for these diseases. At present, the various brand names for adalimumab are imported and registered in Thailand. Consequently, an efficient quality control system of the products, including physicochemical properties and biological activity must be controlled before distribution to the market. Nevertheless, potency assays are not available in the international monographs. As a result, potency analysis is essential for the development and standardisation of methods aimed at increasing laboratory capacity for quality control in a wide range of adalimumab.

Objectives: To verify the validity of biological activity in adalimumab by apoptosis technique using U-937 cells as target cells to be used to standardize the method for laboratory quality control in Thailand.

Methods: This was an experimental study from October 2020 to August 2021 that for method validation of the biological activity of adalimuab by apoptosis on parameters including specificity, precision, robustness, accuracy, linearity, and range by using international standard against the potency of adalimumab.

Results: The results of potency assay demonstrated that this method was specific to the target cells as U-937 cells of adalimumab. Linearity and range showed an R² = 0.996 in a potency range of 50-100% of relative potency. The %GCV of repeatability and intermediate precision differed by analysts and days but did not exceed five. The percent recovery of accuracy ranged from 80 to 125%. In addition, this method exhibited good robustness as the range of %GCV was from 5.74 to 9.57, with no statistically significant differences (p>0.05), and the relative potency assay ranged from 80 to 125% compared to the international reference standard. 

Conclusions: The determination of biological activity for adalimumab by the apoptosis method using U-937 cells as target cells was found to be suitable and reliable for laboratory quality control for both originator and biosimilars of adalimumab.