Maintenance therapy with oral decitabine plus cedazuridine after allogeneic stem cell transplantation for myelodysplastic syndrome.

Disease relapse remains the primary challenge for patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT) for myelodysplastic syndromes. Maintenance therapies with hypomethylating agents are under investigation for use in mitigating relapse in high-risk patients. In this retrospective study, we assessed the safety and efficacy of oral decitabine- cedazuridine maintenance in 18 high-risk myelodysplastic syndromes patients post-HSCT. A total of 66.7% (N=12) received decitabine/cedazuridine (35/100 mg) on days 1 and 3, while 33.3% (N=6) received therapy on days 1-3. Patients completed a median of six treatment cycles (range, 1-20), with one third of patients completing all planned cycles. No unexpected adverse events were observed, with the primary toxicity being myelosuppression. Grade 1-2 upper respiratory tract infections occurred in four patients, and fungal pneumonia in one patient. Overall, patients achieved a median 2-year relapse- free survival of 66.7% (95% confidence interval [CI]: 40.4-83.4) and 2-year overall survival of 72.2% (95% CI: 45.6-87.4), with relapses occurring predominantly in TP53-mutated cases. Prospective clinical trials are essential to confirm the best tolerated dose with potential to improve transplant outcomes.