Azacitidine Indication in Myelodysplastic Syndromes

Introduction to Azacitidine Use

The European Society for Medical Oncology recommends azacitidine for higher-risk Myelodysplastic Syndromes (MDS) patients, where it has demonstrated a survival benefit in randomized trials 1, 2
The American Society of Hematology suggests that azacitidine is not indicated for low-risk MDS due to the lack of survival data in this population 1, 2

Higher-risk MDS (IPSS intermediate-2 or high risk, or IPSS-R intermediate/high/very high risk) is where azacitidine has proven survival benefit in phase III randomized trials 1, 3, 4
The International Prognostic Scoring System (IPSS) intermediate-2 or high-risk patients treated with azacitidine demonstrated 50.8% survival at 2 years versus 26.2% with conventional care (P<0.0001) 3, 4
Lower-risk MDS (IPSS low or intermediate-1 risk) has a fundamentally different natural history with longer survival and lower AML transformation risk, making the risk-benefit calculation entirely different 1, 2

Higher-risk MDS carries a major risk of AML progression and short survival, requiring disease-modifying therapy 1, 2
Lower-risk MDS has a median survival of 5.3-8.8 years (IPSS-R low/very low), where treatment goals focus on managing cytopenias rather than altering disease course 5
The primary treatment approach for lower-risk disease emphasizes supportive care, erythropoiesis-stimulating agents for anemia, and lenalidomide for del(5q) patients 1, 2

IPSS-R very low/low risk: Supportive care, ESAs for anemia, lenalidomide for del(5q) 1, 2
IPSS-R intermediate risk: Individualized based on additional factors (age, comorbidities, cytopenia severity, mutations, response to first-line treatment) 1, 2
IPSS-R high/very high risk: Azacitidine 75 mg/m² for 7 days every 28 days (minimum 6 cycles) or allogeneic transplant 1, 2, 6

Do not use azacitidine in low-risk MDS simply because a patient has transfusion-dependent anemia—first optimize ESA therapy and consider lenalidomide if del(5q) is present 1, 2
Do not extrapolate higher-risk MDS survival data to justify azacitidine use in truly low-risk patients without additional high-risk features 3, 4
Recognize that IPSS-R intermediate-risk represents a gray zone requiring assessment of additional prognostic factors before committing to disease-modifying therapy versus symptom management 1, 2