ADCETRIS® (brentuximab vedotin) is a CD30-directed antibody-drug conjugate (ADC). When it was approved by the Food and Drug Administration (FDA) in August 2011, it became only the second ADC approved by the FDA and the only one on the market at that time following the withdrawal of Mylotarg (gemtuzumab ozogamicin) in June of 2010. The development pathway incorporated nearly all of the FDA incentive development pathways available at that time including fast track and orphan drug designations, priority review, accelerated approval, and special protocol assessment and was the subject of the Oncologic Drugs Advisory Committee. This chapter will describe the US regulatory development path for ADCETRIS, pointing out the key discussion points with the agency and the outcomes.