Overview

Ia: To observe the safety and tolerability of BL-M11D1 in patients with relapsed/refractory acute myeloid leukemia to determine the maximum tolerated dose (MTD) and dose-limiting toxicity (DLT) of BL-M11D1. Ib: Further observe the safety and tolerability of BL-M11D1 at the recommended dose in phase Ia to determine the recommended dose in phase II clinical study (RP2D).

Eligibility

Inclusion Criteria:

1. Voluntarily sign the informed consent and follow the requirements of the protocol.
2. No gender limit.
3. Age: ≥18 years old and ≤75 years old.
4. expected survival time ≥3 months.
5. Relapsed/refractory acute myeloid leukemia (AML) confirmed by histopathology and/or cytology;Patients who met the following criteria were defined as relapsed/refractory AML, including: newly diagnosed patients who failed to respond to 2 courses of standard regimens; Patients who relapsed within 12 months after complete remission after consolidation and intensive therapy; Patients relapsed after 12 months but failed to respond to conventional chemotherapy; Patients with two or more recurrences; Patients with persistent extramedullary leukemia and bone marrow blasts ≥5%; Investigator-assessed patients with relapsed or refractory acute myeloid leukemia who were not or were ineligible for/intolerant of other therapies.
6. ECOG ≤2.
7. Toxicity of previous antineoplastic therapy has returned to grade 1 or less as defined by NCI-CTCAE v5.0 (except for asymptomatic laboratory abnormalities considered by the investigator, such as elevated alkaline phosphatase, hyperuricemia, elevated serum amylase/lipase, and elevated blood glucose; The exception was toxicity that was judged by the investigator to be not a safety risk, such as alopecia, grade 2 peripheral neurotoxicity, and hypothyroidism that was stable with hormone replacement therapy).
8. The level of organ function within 7 days before the first dose meets the following requirements and meets the following criteria:
   1. Liver function: Total bilirubin ≤1.5 ULN (Gilbert's syndrome ≤3 ULN), transaminase (AST/ALT) ≤2.5 ULN (subjects with liver tumor invasive changes ≤5.0 ULN), and/or alkaline phosphatase ≤5 ULN without correction with liver-protective drugs within 7 days before screening;
   2. renal function: creatinine (Cr) ≤1.5 ULN or creatinine clearance (Ccr) ≥50 mL/min (according to the center's calculation criteria);
   3. coagulation function: international normalized ratio (INR) ≤1.5 and activated partial thromboplastin time (APTT) ≤1.5ULN;
   4. proteinuria ≤2+ or ≤1000mg/24h.
9. For premenopausal women with childbearing potential, pregnancy tests must be performed

   within 7 days before starting treatment, serum/urine pregnancy must be negative, and must be non-lactating; All enrolled patients (male or female) were advised to use adequate barrier contraception throughout the treatment cycle and for 6 months after the end of treatment.

Exclusion Criteria:

1. Acute promyelocytic leukemia, acute transformation of chronic myeloid leukemia.
2. Antineoplastic therapy, including chemotherapy, biologic therapy, immunotherapy, definitive radiotherapy, major surgery (investigator-defined), or targeted therapy (including small-molecule tyrosine kinase inhibitors), has been administered within 4 weeks or 5 half-life cycles (whichever is shorter) before the first dose; Or palliative radiotherapy within 2 weeks before the first dose.
3. History of severe heart disease, such as left ventricular ejection fraction < 50%, history of symptomatic congestive heart failure (CHF) ≥ grade 2 (CTCAE v5.0), New York Heart Association (NYHA) ≥ grade 2 heart failure, history of myocardial infarction, unstable angina, etc.
4. Prolonged QT interval (QTc > 450 msec in men or QTc > 470 msec in women), complete left bundle branch block, and III degree atrioventricular block.
5. Active autoimmune diseases and inflammatory diseases, such as systemic lupus erythematosus, psoriasis requiring systemic treatment, rheumatoid arthritis, inflammatory intestinal diseases and Hashimoto's thyroiditis, etc., excluding type I diabetes mellitus, hypothyroidism that can only be controlled by replacement therapy, and skin diseases without systemic treatment (such as vitiligo and psoriasis).
6. Other malignancies diagnosed within 5 years before the first dose, except for radical basal cell carcinoma, squamous cell carcinoma, and/or radical resection carcinoma in situ.
7. Poorly controlled hypertension (systolic blood pressure &gt; 150 mmHg or diastolic blood pressure &gt; 100 mmHg).
8. Patients with pulmonary disease grade ≥3 defined by CTCAE v5.0, current or previous interstitial lung disease (ILD).
9. Patients with central nervous system involvement.
10. Patients with a history of allergy to recombinant humanized antibody or human-mouse chimeric antibody or to any of the ingredients of BL-M11D1.
11. Prior organ transplantation or allogeneic hematopoietic stem cell transplantation (Allo-HSCT).
12. Human immunodeficiency virus (HIVAb) positive, active tuberculosis, active hepatitis B virus infection (HBsAg positive; HBcAb positive and HBV-DNA copy number > lower detection limit) or active hepatitis C virus infection (HCV antibody positive and HCV-RNA > lower detection limit).
13. Active infection requiring systemic treatment, such as severe pneumonia, bacteremia, sepsis, etc.
14. Presence of pleural, abdominal, pelvic or pericardial effusion with clinical symptoms or requiring repeated drainage.
15. Had participated in another clinical trial within 4 weeks before the first dose (calculated from the time of last dose).
16. Pregnant or lactating women.
17. Other conditions for participation in the trial were not considered appropriate by the investigator.