Dose Escalation Study of JNJ-63709178, a Humanized CD123 x CD3 DuoBody in Participants With Relapsed or Refractory Acute Myeloid Leukemia (AML)

The purpose of this study is to characterize the safety and tolerability of JNJ-63709178 and identify the recommended Phase 2 dose(s) (RP2D) and schedule for JNJ-63709178 in Part 1 and to characterize the safety and tolerability of JNJ-63709178 at the RP2D(s) in Part 2.

This is first-in-human (FIH) Phase 1, open-label (identity of assigned study drug will be known), multicenter, dose escalation study with dose expansion to identify the RP2D and to evaluate the safety, tolerability, and preliminary antitumor activity of JNJ-63709178 in adult participants with relapsed or refractory acute myeloid leukemia (AML) who are ineligible for or have exhausted standard therapeutic options. The study will be conducted in 2 parts: dose escalation and dose expansion. The study is divided into 3 periods: a Screening Phase (within 28 days before the first dose of study drug), a Treatment Phase (first dose of study drug until the last dose of study drug) and a Post-treatment Follow-up Phase (up to the end of study participation or end of study). Participants' safety will be monitored throughout the study.