Efficacy and Toxicity Of Decitabine Versus CHG Priming Regimen In Patients With Higher Risk Myelodysplastic Syndrome

Decitabine has been approved for the treatment of myelodysplastic syndrome (MDS). CHG regimen (low-dose cytarabine and homoharringtonine in combination with granulocyte colony-stimulating factor (G-CSF)) has been reported to be effective in higher risk MDS patients. The comparative efficacy of these 2 forms of treatment in MDS is unknown. The objective of the current study was to compare the efficacy and toxicity of decitabine and CHG regimen in higher risk MDS.

We compared lower intensity decitabine with CHG regimen in higher risk MDS (International Prognostic Scoring System (IPSS) intermediate- or high-risk or chronic myelomonocytic leukemia (CMML)). Decitabine was given 20 mg/m² intravenously over 1 hour daily for 5 days. CHG chemotherapy consisted of an intravenous continuous infusion of low-dose cytarabine (25 mg/d) (days 1–14) and homoharringtonine (1 mg/d) (days 1–14) in combination with G-CSF (300 μg/d) by subcutaneous injection from day 0 until peripheral neutrophil count recovery to 2.0× 10⁹/L. The complete remission (CR), overall response (OR), overall survival and toxicity was compared between the two groups.

A total of 132 patients with higher risk MDS were enrolled in this study, 70 cases in decitabine group and 62 cases in CHG group. The CR rate was 25.7% with decitabine, compared to 32.3% with CHG regimen (p=0.538). The overall response rate (including CR, partial remission (PR), marrow CR and hematological improvement (HI)) between the two groups was also not significantly different (68.6% with decitabine and 58.1% with CHG regimen) (p = 0.209). Overall survival was not significantly different between the two groups (median survival: 18.2 months in decitabine group vs 15.3 months in CHG group; p=0.176). Grade 4 neutropenia occurred more frequently with decitabine (58.3 %) than with CHG regimen (32.3 %) (p = 0.004). Grade 4 thrombocytopenia was also more frequently with decitabine (61.4 %) than with CHG regimen (38.7 %) (p = 0.009).

Both decitabine and CHG regimens were effective in treating patients with higher risk MDS. The two regimens did not differ in terms of clinical responses. However, decitabine showed severer hematological toxicities than CHG regimen. This trial was registered at www.clinicaltrials.gov as ChiCTR-ONC-11001501.

No relevant conflicts of interest to declare.