Study GLB-001-01 is a first-in-human (FIH), Phase 1, open-label, dose escalation and expansion clinical study of GLB-001 in participants with relapsed or refractory acute myeloid leukemia (R/R AML) or in participants with relapsed or refractory higher-risk myelodysplastic syndromes (R/R HR-MDS). The dose escalation part (Phase 1a) of the study will evaluate the safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD) and preliminary efficacy of GLB-001 administered orally. Approximately 24 participants (up to 42 participants) may be enrolled in Phase 1a of the study.

The dose expansion part (Phase 1b) will be followed to understand the relationships among dose, exposure, toxicity, tolerability and clinical activity, to identify minimally active dose, and to select the recommended dose(s) for phase 2 study. Up to 24 participants (12 participants per dose level) may be enrolled in Phase 1b of the study.

A standard 3+3 dose-escalation design will be applied to evaluate a set of several dose levels to determine the maximum tolerated dose (MTD) or maximum administered dose (MAD) of GLB-001 in R/R AML or R/R HR-MDS patients who are eligible for DLT evaluation. The actual dose-escalation magnitude or dosing frequency may be adjusted based on the available PK and safety data in human.

After the MTD or MAD of GLB-001 is defined in Phase 1a, 1 or 2 dose levels will be selected for expansion per safety review committee (SRC) recommendation, approximately 12 patients will be enrolled per dose level. Recommended phase 2 dose (RP2D) will be selected based on the results of PK, PD, safety and efficacy in the dose escalation and expansion study.

Inclusion Criteria:

• Participants is ≥ 18 years of age at the time of signing the Informed Consent Form (ICF).

• Participants must understand and voluntarily sign an ICF prior to any study-related assessments/procedures being conducted.

• Participants are willing and able to adhere to the study visit schedule and other protocol requirements.

• Participants with histologically or cytologically confirmed AML including de novo AML or secondary AML transformed from MDS according to 2022 World Health Organization (WHO) criteria classification, or with histologically or cytologically confirmed HR-MDS.

• R/R AML and R/R HR-MDS who have failed or are ineligible for all available therapies which may provide clinical benefit.

• Participants must have the following screening laboratory values:

  • Total white blood cell count (WBC) < 25 x 10^9/L prior to the first dose of the study drug.
  • Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤ 3.0 × upper limit of normal (ULN), unless considered due to extensive leukemic liver involvement, in which case AST and ALT can be ≤ 5.0 x ULN.
  • Serum total bilirubin ≤ 1.5 x ULN, unless considered due to Gilbert's syndrome, in which case serum total bilirubin < 3 x ULN.
  • Estimated serum creatinine clearance of ≥ 60 mL/min using the Cockcroft-Gault equation. Measured creatinine clearance from a 24-hour urine collection is acceptable if clinically indicated.
  • International normalized ratio (INR) ≤ 1.5 x ULN and active partial thromboplastin time (aPTT) ≤ 1.5 x ULN.

• Life expectancy ≥ 12 weeks.

• Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 to 2.

• Female Participants of child-bearing potential must have a negative serum or urine pregnancy test at screening and at pre-dose on Cycle 1 Day 1 (C1D1).

Exclusion Criteria:

• Participants with acute promyelocytic leukemia (APML).
• Participants with known leukemic involvement in central nervous system (CNS).
• Receipt of anticancer medications/therapies within 5 half-lives or 28 days before the first administration of the study drug.
• Participants with unresolved clinically significant non-hematologic toxicities of ≥ Grade 2 AE from prior therapies with exception of residual alopecia.
• Participants with chronic graft versus host disease (GVHD) requiring systemic immunosuppressive therapy.
• Participants with active malignancies other than AML or MDS.
• Participants who have undergone major surgery ≤ 4 weeks prior to the first dose of the study drug.
• Participants with immediately life-threatening, severe complications of leukemia such as disseminated/uncontrolled infection (bacterial and/or fungal), uncontrolled bleeding, and/or uncontrolled disseminated intravascular coagulation.
• Participants with known chronic, active infection of hepatitis B virus (HBV), hepatitis C virus C (HCV), human immunodeficiency virus (HIV).
• Participants unable to swallow oral medications, or Participants with clinically significant diarrhea, vomiting or malabsorption felt limited absorption of orally administered medications.
• Participants with any other significant medical conditions, any other conditions, laboratory abnormality, or psychiatric illness which place the Participants at unacceptable risk if he/she were to participate in the study or that would hamper the Participants understanding of the study, or would prevent the Participant from complying with the study.
• Medications or supplements that are known to be strong and moderate inhibitors or inducers of CYP450 isozyme 3A4 (CYP3A4) and/or P-glycoprotein (P-gp), or strong inhibitors or inducers of CYP450 isozyme 2C8 (CYP2C8) within 14 days or 5 half-lives, whichever is shorter, before the first dose of study drug.
• Pregnant or lactating women.