Astellas Pharma and Ambrx have entered into a collaboration for the discovery and development of novel antibody drug conjugates (ADCs), which allow for the targeted delivery of drugs. Ambrx creates optimized ADCs using its site-specific conjugation technology along with linkers and payloads. Ambrx ADCs have demonstrated high potency and a wide therapeutic index in preclinical studies.   Ambrx will receive an upfront payment of $15 million and as much as $285 million in potential research, develo...