Auristatin peptides, including MeVal-Val-Dil-Dap-Norephedrine (MMAE) and
MeVal-Val-Dil-Dap-Phe (MMAF), were prepared and attached to Ligands
through various linkers, including maleimidocaproyl-val-cit-PAB. The
resulting ligand drug conjugates were active in vitro and in vivo.