Steven Horwitz, MD, PhD, Memorial Sloan-Kettering Cancer Center, New York, NY, reports updates from the first-in-human Phase I dose-escalation and expansion study (NCT02663518) of TTI-621, a novel biologic targeting the CD47 pathway in multiple hematologic malignancies. TTI-621 is a soluble SIRPα fusion protein that is designed to promote tumor cell phagocytosis and antitumor activity. During the initial dose-escalation study in 214 patients, thrombocytopenia did not increase with TTI-621 dose. A dose-expansion study in 15 patients with cutaneous T-cell lymphoma demonstrated that doses of 1.4 mg/kg are safe and well-tolerated. Preliminary efficacy data has also indicated antitumor activity, although reliability of these results will be confirmed as the study continues and dose is optimized further. This interview took place during the 62nd American Society of Hematology (ASH) Annual Meeting and Exposition, 2020.