Mark Levis, MD, PhD, Johns Hopkins Sidney Kimmel Comprehensive Cancer Center, Baltimore, MD, discusses the APL0406 clinical trial (NCT00482833) that led to the approval of arsenic trioxide (ATO) and all-trans retinoic acid (ATRA) without chemotherapy for the treatment of acute promyelocytic leukemia (APL). This trial demonstrated that patients treated only with ATO+ATRA experienced long-term survival rates between 95-100%. This interview took place at the 2021 Relapse After HSCT² Workshop in New York, NY.