Phase 2 study of chidamide in combination with CAG and venetoclax-azacitidine in older patients with newly diagnosed acute myeloid leukemia.

Introduction: Older patients with acute myeloid leukemia (AML) respond poorly to standard induction therapy. DNA methyltransferases (DNMTs) and histone-deacetylases (HDACs) are key regulators of gene expression in cells and have been investigated as important therapeutic targets. However, their effects remains unclear as induction therapy for AML.

Methods: Previously untreated AML patients aged 60 years and over (N=40) were enrolled into this single arm, open-label, phase 2 study to evaluate the clinical efficacy and safety of chidamide combined with CAG and venetoclax-azacitidine (referred to as CACAG-VEN) in elderly AML patients (ClinicalTrials.gov:NCT05659992). All patients received induction treatment with aclarubicin (10 mg/m2/d on days 1, 3, and 5), azacitidine (75 mg/m2 on days 1-7), cytarabine (75 mg/m2 bid on days 1-5), chidamide (30 mg, twice/week for 2 weeks), and venetoclax (100 mg on day 1, 200 mg on day 2, 400 mg on days 3-14). Granulocyte colony-stimulating factor 5 mg/kg/day was administered.

Results: Theoverall response rate was 97.5%, with a composite complete response (CRc) rate of 85.0% after one cycle of CACAG-VEN. Patients with adverse risk according to the ELN guidelines had CRc rates of 81.3%. No patients experienced early death within 30 days of therapy initiation. Grade 3 - 4 non-hematological adverse events included febrile neutropenia in 15 (37.5%) of 40 patients, pneumonia in three (7.5%), sepsis in two (5.0%) and blood bilirubin increase in one (2.5%). The 12-month overall survival rate was 73.4% (95% CI: 55.9-84.8%). The median time to recovery was 15.0 (IQR 10.0-19.5) days for platelets ≥ 20000/mL and 13.0 (IQR 10.5-17.0) days for an absolute neutrophil count ≥ 1000 cells/mL after induction therapy.

Discussion: In conclusion, chidamide in combination with CAG and venetoclaxazacitidine was effective and well tolerated in elderly patients with AML.

Clinical Trial Registration: https://www.clinicaltrials.gov/, identifier NCT05659992.