John Mascarenhas, MD, Icahn School of Medicine at Mount Sinai, New York, NY, discusses two Phase Ib studies (NCT04454658, NCT04480086) evaluating the safety and efficacy of the BET inhibitors ABBV-744 and mivebresib in myelofibrosis patients. ABBV-744 and mivebresib will be used in multiple cohorts of patients undergoing salvage therapy, including those previously treated with ruxolitinib and those having a suboptimal response to their current treatment. These studies will also investigate ABBV-744 and mivebresib in combination with ruxolitinib or navitoclax. This interview took place during the 62nd American Society of Hematology (ASH) Annual Meeting and Exposition, 2020.