Chidamide, decitabine, cytarabine, aclarubicin, and granulocyte colony-stimulating factor (CDCAG) in patients with relapsed/refractory acute myeloid leukemia: a single-arm, phase 1/2 study

BACKGROUND: Epigenetic mechanisms play an important role in the chemoresistance of acute myeloid leukemia (AML). The clinical response to epigenetic modifier-based chemotherapy in patients with relapsed/refractory AML (r/r AML) is unclear. This multicenter clinical trial evaluated the safety and efficacy of epigenetic modifiers (chidamide and decitabine) in combination with aclarubicin, cytarabine, and granulocyte colony-stimulating factor (G-CSF) in patients with r/r AML. RESULTS: Adult patients with r/r AML were treated with chidamide, decitabine, cytarabine, aclarubicin, and G-CSF (CDCAG). The primary measures were overall response (OR), overall survival (OS), and safety. Next-generation sequencing was performed to analyze the correlation between gene mutations and response. A total of 93 patients with r/r AML were enrolled. Overall, 24 patients had a complete remission (CR) and 19 patients achieved CR with incomplete blood count recovery (CRi). The overall response rate (ORR) was 46.2%. The overall survival of these 43 patients who achieved CR/CRi was significantly longer than that of patients who failed to achieve remission (563 vs 152 days, P < 0.0001). Of the patients with mutations in epigenetic and transcription factor-related genes, but without internal tandem duplications in FMS-like tyrosine kinase3 (FLT3-ITDs), 55.6% achieved CR/CRi, whereas the ORR was 28.2% for patients with mutations in other genes. CONCLUSIONS: The CDCAG regimen was well tolerated and effective in r/r AML. Patients with epigenetic and transcription factor-related gene mutations, but without FLT3-ITD mutations, may benefit from this regimen. TRIAL REGISTRATION: Clinical Trials, NCT02886559. Registered 01 September 2016