Eligible patients (18-75 years) have relapsed/refractory AML, ECOG &le;2, and adequate organ function. Exclusions include prior transplants, heart/lung conditions (e.g., QT prolongation, ILD), HIV/HBV/HCV infections, uncontrolled hypertension, autoimmune diseases, recent chemotherapy (<4 weeks), or pregnancy. Investigators may exclude unsuitable candidates.

This study enrolled patients with R/R AML aged 18-75 years. For dose escalation (D-ESC i3+3), BL-M11D1 was administrated intravenously in dose cohorts from 0.6mg/kg up to 4.4mg/kg once a week (QW) in 28-day cycles for induction treatment, followed by administration every two weeks (Q2W) at the same initial dose for consolidation treatment in pts whose bone marrow (BM) blast <5%. A subset of pts were enrolled in dose-expansion (D-EXP) at 1.65, 2.2 mg/kg doses.

Eligible patients (&ge;18 years) have relapsed/refractory CD33+ AML, ECOG 0-2, adequate organ function, and life expectancy &ge;3 months. Exclusions include APL/CML, recent chemotherapy (<2 weeks/5 half-lives), uncontrolled heart disease, active infections, severe lung conditions (ILD), CNS leukemia, pregnancy, or conditions deemed unsafe by investigators. HIV/HBV/HCV-positive patients with detectable viral loads are excluded.

The study evaluates BL-M11D1 safety by monitoring dose-limiting toxicities (DLTs) including severe TEAEs (≥Grade 3), treatment discontinuation events, and hematologic/nonhematologic toxicities over 1 year. Key safety endpoints include determining the maximum tolerated dose (MTD), minimum safe and effective dose (MSED), and assessing serious adverse events (SAEs).