Prospective clinical study on the efficacy and safety of the DCIA±X regimen in treating relapsed/refractory acute myeloid leukemia

Abstract Background: Patients with relapsed/refractory acute myeloid leukemia (R/R AML) face dismal outcomes, highlighting the critical need for effective salvage therapies. The DCIA±X regimen—combining decitabine, cladribine, idarubicin, cytarabine, and optional targeted agents (X)—leverages synergistic mechanisms to overcome chemoresistance. In a previous retrospective study, a total of 10 patients with R/R AML were treated with the DCIA ±X regimen, and nine patients with R/R AML reached complete remission with/without count recovery (CR/CRi) after one course of treatment, with a CR of 90%. Bridging hematopoietic stem cell transplantation was successful in four of these patients. Consequently, a prospective study was conducted employing the DCIA±X regimen to evaluate the effectiveness and safety of the intervention in R/R AML. Methods: This single-arm prospective study was conducted at Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology. Patients aged 18-60 years diagnosed with R/R AML were included. All patients received DCIA±X regimen: decitabine (20mg/m2/day days 1–5), cladribine (5mg/m2/day days 4–8), idarubicin (10mg/m2/day days 4–6), cytarabine (100-200mg/m2/day days 4–10), X (according to targeted agents). The Ethics Committee of Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology (TJ-IRB202303151) approved this prospective study. Data analysis was performed using SPSS (version 27). Results: This prospective cohort study enrolled 22 R/R AML patients (including 14 males and 8 females). The median age was 45 years (IQR 35-50). Disease status included relapse (40.9%) and primary refractory (59.1%). Baseline characteristics included Initial blood routine [median WBC 3.15×10⁹/L (IQR 1.44-127.72), Hb 72 g/L (IQR 62.30-90.00), PLT 60×10⁹/L (IQR 27.30-94.30)] and bone marrow blast burden (median 50% [IQR 28-75]). Initial chromosomal abnormalities were detected in 17 out of 22 cases, while gene mutations were identified in 16 out of 22 cases. CR/CRi was 81.8% (n=18), with a partial response (PR) rate of 13.6% (n=3), yielding an overall response rate (ORR) of 95.4% (n=21). Non-response (NR) occurred in 1 patient (4.5%). Subsequently, 63.6% (n=14) underwent allogeneic transplantation. The 1-year relapse-free survival (RFS) and overall survival (OS) were 68.5% and 84.78%, respectively. Hematologic toxicity was manageable, with the median time to neutrophil recovery of 17 days (IQR 14-20) and platelet recovery of 19 days (IQR 9-21).Conclusion: This novel reinduction regimen demonstrated robust activity and acceptable toxicity in treating R/R AML patients, achieving high CR/CRi and ORR rates, facilitating successful bridge to transplant in most responders, and promising 1-year RFS and OS.