Antibody-drug conjugates- stability and formulation.

The number of antibody-drug conjugates (ADCs) on the market is expected to multiply in the upcoming years. The main reason: this novel drug delivery system combines the benefits of the selectivity of the antibody and the potency of the cytotoxic agent. The interplay of the antibody, linker and payload, however, calls for a stable and unique formulation. In this review, the literature on the stability of marketed ADCs and the respective formulations are summarized and used as a basis to give general formulation considerations for ADCs. Whereas the same excipients are used as in antibody formulations, specific focus is on the ionic strength and concentrations of the excipients of the ADC. Further, a short outline of the analytical toolbox to characterize ADC formulations is included.