Abstract The selection of host cell lines and culture media plays a central role in influencing the quality attributes of monoclonal antibodies, particularly in biosimilar development and process comparability. This study used standardized upstream conditions to evaluate the impact of host cell line selection on product quality attributes of a non‐originator version of the NISTmAb by comparing results from antibodies made in murine myeloma NS0 or Chinese Hamster Ovary (CHO) cells. NISTCHO and NS0 clones achieved comparable peak density and productivity when cultured identically, demonstrating the critical role of media formulation for NISTCHO performance. Distinct cell line‐specific differences were noted in aggregation, fragmentation, charge variant distribution, and glycosylation profiles. Non‐originator NISTmAb derived from NS0 cells exhibited glycoforms that were nearly 100% fucosylated with higher relative levels of sialylation and galactosylation. The NS0‐derived material also displayed elevated levels of acidic charge variant species, decreased main charge variant species, and increased aggregation. Conversely, non‐originator NISTmAb derived from NISTCHO exhibited an average of 15–20% relative afucosylation, resulting in an increased binding affinity to FcγRIIIa, which can be of critical importance to quality due to potential enhancement of ADCC potency. These results highlight the intrinsic biology of the host cell line and culture media composition as influential factors for microheterogeneity in post‐translational modifications and structural characteristics. As of December 2025, 14 (17.3%) of FDA‐approved biosimilars are manufactured using a different cell type than that of the originator product, necessitating comparisons among cell substrates and their effect on product quality of interest for comparative analytical assessment.
Bush et al. (Wed,) studied this question.