Vertical integration for CDMOs in ADC manufacturing offers an opportunity to reduce costs. This approach also creates a more resilient supply chain. ADCs are a proven technology platform that, by precisely targeting an antibody, delivers the active substance directly where it is needed. ADCs use a highly potent toxin that binds to a monoclonal antibody to target tumor cells directly without damaging normal tissue. The ADC method is not new, but advances in target identification, antibody preparation, linker and toxin development have made it a promising platform. Successful production of biologics, including ADCs, depends on product reproducibility through sophisticated cell line development and quality control.