Innovative approach to support therapeutic proteins’ similarity in hydrodynamic size using high-throughput dynamic light scattering and forced degradation

Comparative analytical assessment (CAA) between the reference product and the proposed product forms the basis of the biosimilarity demonstration. Though Dynamic Light Scattering (DLS) has been implemented for CAA, its capability beyond signature peak for similarity assessments has remained unexplored. Herein, we have developed a innovative forced degradation based sweet spot method consisting of signature peak, temperature range, increment and hold time using high throughput-DLS (HT-DLS) to show similarity in hydrodynamic size between products. In our study, we used rituximab, its biosimilars, and insulin analogs as model products to demonstrate product similarity in hydrodynamic size (D_h) size through the HT-DLS sweet spot approach. Our data indicate that temperature range, temperature increment, hold time, and regularization algorithm, all play a role in showing analytical similarity in D_h size. Our data also indicate that establishing DLS signature peaks of the products is insufficient to show analytical similarity in D_h size distribution. Additionally, the temperature range (sweet spot) varies from product to product. Principal component analysis modeling was used for detailed data interpretation. Overall, our HT-DLS based sweet spot method provided informative data to support similarity in D_h size distribution.