D8-MMAD is a deuterated form of MMAD, which is a microtubule destroyer.

MMAD (monomethyl Dolastatin 10) is coupled through a stable oxime ligation process to produce several nearly uniform antibody-drug conjugates (ADC) with a pharmacodynamic ratio of approximately 2.0. The resulting conjugate showed good pharmacokinetic properties and had strong in vitro cytotoxic activity against HER2 + cancer cells. Compared with ADCs prepared by cysteine alkylation after reduction of natural interchain disulfide bonds, site-based unnatural amino acid-based ADCs have higher cytotoxicity in vitro.

The resulting antibody-drug conjugate (ADC) showed complete tumor regression in rodents. Their toxicological characteristics in rats have also been improved.