ARX788 is an anti-HER2 antibody drug conjugate (ADC) developed using Ambrx proprietary Engineered Precision Biologics technology. The manufacturing process of ARX788 has been optimized during the course of early to late-phase clinical development. A comprehensive evaluation of side-by-side comparability between pre- and post-change process for ARX788 drug substance and drug product from a quality perspective was conducted based on ICH Q5E guidelines consisting of batch release assays, physicochemical and biophysical characterization, biological characterization, and forced degradation studies. All results have substantiated a high degree of similarity between the pre- and post-change ARX788 drug substance batches and drug product lots, demonstrating that the process manufacturing changes did not impact product quality.