Abstract
Objective: This study aimed to evaluate the efficacy and safety of venetoclax (VEN) combined with hypomethylating agents (HMA) in the treatment of higher-risk myelodysplastic syndromes (HR-MDS) and analyze the factors influencing their therapeutic effect. Methods: The clinical data of 83 patients with HR-MDS who were diagnosed at the First Affiliated Hospital of Zhengzhou University between November 2019 and May 2023 were retrospectively analyzed. All patients were treated with VEN combined with HMA. The Kaplan-Meier method was used to depict the survival curves, and the log-rank test was used to compare survival between the groups. Results: The median age was 57 (15-82) years old, and 51 patients (61.4%) were male. Forty-five patients (54.2%) were initially treated with HMA, 23 (27.7%) received ≤4 cycles of HMA, and 15 (18.1%) demonstrated HMA failure. At the median follow-up of 10.3 (0.6-34.4) months, the overall response rate (ORR) was 62.7% (52/83), including 18 patients (21.7%) with a complete response (CR), 14 (16.9%) with a bone marrow CR (mCR) with hematological improvement, and 20 (24.1%) with a mCR. The ORR of patients with initial treatment, ≤4 HMA cycles, and HMA failure were 66.7%, 60.9%, and 53.3%, respectively (P=0.641). The median overall survival time was 14.6 (95% CI 7.2-22.0) months, and the median progression-free survival time was 8.9 (95% CI 6.7-11.1) months. The multivariate analysis showed that serum alkaline phosphatase (ALP) ≥90 U/L (OR=14.574, 95% CI 3.036-69.951, P=0.001), TP53 mutation (OR=13.052, 95% CI 1.982-85.932, P=0.008), and U2AF1 mutation (OR=7.720, 95% CI 1.540-38.698, P=0.013) were independent risk factors for poor efficacy of VEN combined with HMA. Hematological toxicity occurred in all patients, and the incidence of treatment-induced grade 3-4 leukopenia was 48.2% (40/83). Infection was the most common non-hematological adverse event, mainly pulmonary infection (31.3%) . Conclusion: VEN combined with HMA had a high response rate in patients with HR-MDS, both at initial treatment and with HMA failure. ALP ≥ 90 U/L, TP53 mutation, and U2AF1 mutation were independent risk factors for non-response to treatment.