Anetumab ravtansine (BAY 94-9343) is a selective and highly potent antibody-drug conjugate (ADC) to target maytansinoid tubulin. Anetumab ravtansine consists of a human anti-mesothelin antibody conjugated to the maytansinoid tubulin inhibitor DM4. Anetumab ravtansine shows antitumor efficacy correlated with the amount of mesothelin expressed in patient-derived xenograft tumor models.