This is the first-in-human trial with BYON4413 to evaluate safety, PK, immunogenicity, and anti-leukemia activity of BYON4413 in patients with AML or MDS.

This trial includes two parts. Part 1 is a dose escalation study in which the maximum tolerated dose and recommended dose for expansion of BYON4413 will be determined. Part 2 is an expansion study to evaluate the anti-leukemia activity and safety of BYON4413.

Inclusion Criteria:

• Patients who have progressed on standard therapy or have no established alternative treatment, with a diagnosis of:

  • R/R AML (WHO 2022) OR
  • MDS (WHO 2022) with ≥10% blasts in BM and have received ≥3 cycles of HMA

• Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1 or 2;

• Adequate baseline organ function.

Exclusion Criteria:

• Having been treated with any CD123-targeting therapies;
• Having received allogeneic hematopoietic stem cell transplantation within 100 days prior to start Cycle 1 Day 1;
• Having treatment-related toxicities from prior anti-leukemia therapies that have not resolved to CTCAE Grade ≤ 1;
• Having active central nervous system AML or AML of the APL/M3 subtype;
• History of keratitis;
• History of specified lung or renal disease;
• Having clinically significant cardiovascular disease;
• Known infection of Hepatitis B, C or E.

Key inclusion and exclusion criteria details are listed here, additional requirements may apply.