Cell Line Development for Bispecific Antibodies: Better Predictability Through Transposases

Bispecific antibodies are at the forefront of biopharmaceutical drug development. With over 100 different molecular architectures combined with diverse individual subunit sequences, choosing the most suitable structure and predicting the ideal subunit expression ratios for successful heterodimerization is a significant challenge. In this paper, we demonstrate that the recently described cell line development paradigm shift (Rajendran et al . 2021), enabled by the Leap-In transposon platform, can be extended to the development of bispecific monoclonal antibody-producing cell substrates (stable clones and pools). The key features are 1) Parental pools reliably predict the derivative clonal productivity and clonal heterodimer fractions. 2) Clonal productivity and clonal heterodimer fraction remained stable for at least 60 population doublings. 3) Depending on the products’ biophysicochemical properties, the stable pools exhibit variable productivity stability. 4) Heterodimer fractions remain stable in the Leap-In mediated stable pools independently of the productivity stability of the pools. 5) Structures and subunit ratios can be triaged at stable pool level, and 6) Due to the homogeneous clonal productivity distribution, only a small number (∼50) of clones need to be isolated and characterized.