It is Never Too Late for a Cocktail - Development and Analytical Characterization of Fixed-dose Antibody Combinations.

Monoclonal antibodies (mAbs) have been immensely successful as biological drugs. However, the treatment of some diseases requires combinations of antibodies that bind to different pharmacological targets. An elegant approach to delivering the therapeutic potential of antibody combinations is to develop drug products based on fixed-dose combinations (FDCs) of co-formulated mAbs. Since the first FDA approval of two co-formulated mAbs in 2020, the interest in antibody FDCs is increasing. However, there are different strategies to develop co-formulated antibodies and unique challenges related to their analytical characterization. In this review, we summarize the recent progress on antibody FDCs with a focus on important considerations during drug development and the analytical toolbox for co-formulated mAbs.