Statistics of the Distribution of the Abundance of Molecules with Various Drug Loads in Maytansinoid Antibody–Drug Conjugates

The maytansinoid antibody–drug conjugates (ADCs) in clinical development for cancer therapy each contain a derivative of the microtubule-targeting agent, maytansine, covalently attached to the antibody via an engineered linker. A sample of any of these conjugates contains molecules with different numbers of maytansinoid molecules, or “drug” loads, the relative abundance of which can be determined by mass spectrometry. We examined the accuracy of...