BY002 IIT Study in R/R Acute Leukemia

Inclusion Criteria:

* Age ≥16 years.
* Confirmed diagnosis of AML, ALL, or MPAL per WHO 2022 criteria.
* Relapsed or refractory disease after ≥1 prior therapy.
* Presence of KMT2A rearrangement or NPM1 mutation (preferred, but not exclusive).
* ECOG performance status 0-2.
* Adequate organ function:
* ANC ≥1.0 × 10⁹/L (unless cytopenia due to leukemia)
* Platelets ≥50 × 10⁹/L (unless due to leukemia)
* ALT/AST ≤2.5 × ULN, bilirubin ≤1.5 × ULN
* Creatinine clearance ≥50 mL/min
* Negative pregnancy test for women of childbearing potential.
* Willing to use effective contraception during study and 90 days after last dose.
* Signed informed consent.

Exclusion Criteria:

* Active central nervous system (CNS) leukemia. (Prior CNS involvement allowed if treated and controlled; CNS prophylaxis permitted.)
* History of significant liver disease, including viral hepatitis or cirrhosis:
* HBsAg positive must have negative HBV DNA.
* HCV antibody positive must have negative HCV RNA.
* Known HIV infection.
* Pregnant or breastfeeding women.
* Significant cardiac disease:
* Congenital long QT syndrome or QTcF \>450 msec.
* Acute myocardial infarction, unstable angina, or coronary artery bypass within 6 months.
* Congestive heart failure ≥ NYHA class II.
* History of another malignancy within 5 years, except adequately treated basal cell carcinoma of the skin, in-situ breast cancer, or in-situ cervical cancer.
* Autologous HSCT or CAR-T therapy within 60 days, or unresolved toxicities from ASCT/CAR-T.
* Allogeneic HSCT within 100 days, or active GVHD, or requiring ongoing immunosuppressive therapy.
* Anti-leukemia therapy within 2 weeks before study entry (hydroxyurea permitted).
* Prior investigational drug use: \<2 weeks or \<5 half-lives for small molecules; \<4 weeks or \<5 half-lives for biologics (whichever is shorter).
* Unresolved toxicities \> grade 1 from prior anti-leukemia therapy (except alopecia).
* Uncontrolled active infection:
* Mild infections manageable with oral/topical treatment are allowed.
* Serious infections requiring hospitalization/IV antibiotics within 14 days excluded, unless resolved.
* Febrile neutropenia without infection evidence may be eligible if afebrile \>72 h without antipyretics.
* Active tuberculosis excluded.
* Conditions impairing oral intake or absorption (e.g., swallowing difficulty, short bowel syndrome, gastroparesis).
* Known severe allergy to Menin inhibitors or any component of BY002.
* Investigator judges poor compliance or inability to complete study.
* Any other serious disease, abnormality, or condition that may increase risk, interfere with study drug, confound results, or expected survival ≤6 months.