Azacitidine Treatment Regimen for Myelodysplastic Syndromes

Standard Dosing Regimen

The European Society for Medical Oncology recommends azacitidine should be administered at 75 mg/m² subcutaneously daily for 7 consecutive days every 28 days, with at least 6 cycles required to properly evaluate efficacy 1, 2, 3, 4
The standard route of administration is subcutaneous injection 1, 5, 6, 7
An alternative "5-2-2" regimen (5 days on, 2 days off, 2 days on) is considered acceptable and often easier to apply in clinical practice, although it has not demonstrated survival advantage in higher-risk MDS compared to the 7-day regimen 1, 2, 3, 4, 5, 6, 7

At least 6 cycles of azacitidine are mandatory before evaluating treatment efficacy, as most patients only respond after several courses 1, 2, 3, 4, 5, 6, 7
Hematological improvement (HI) according to IWG 2006 criteria should be considered indicative of response, as it is associated with prolongation of survival compared with supportive care 1, 2, 5, 6, 7

Higher-risk MDS patients (IPSS-R intermediate, high, or very high risk) without major comorbidities are appropriate candidates for azacitidine treatment 1, 2, 3, 4
Patients >70 years or younger patients without a donor for allogeneic stem cell transplantation are also suitable candidates 1, 2, 3, 4

2-6 cycles of azacitidine are commonly used before hematopoietic stem cell transplantation to reduce bone marrow blasts or for logistical reasons 1, 2, 3, 4
Fit patients ≤70 years with a donor should proceed to allogeneic stem cell transplantation, preceded or not by azacitidine 1, 2, 3, 4

Do not discontinue treatment before 6 cycles unless there is clear disease progression or unacceptable toxicity, as delayed responses are common 1, 2, 5, 6, 7
Do not use 5-day regimens as standard in higher-risk MDS without understanding they have not demonstrated survival advantage compared to the 7-day regimen 5, 6, 7