Azacitidine 已被美國和臺灣Food and Drug Administration (FDA) 核准用於骨髓化生不良症候群(myelodysplastic syndromes, MDS) 之適應症，證實可減少高危險群MDS 轉化成急性骨髓性白血病 (acutemyeloblastic leukemia, AML) 的風險，且是唯一在低甲基化藥物 (hypomethylation agents) 中被證實可延長總存活率，因而建議當作高危險群MDS 之第一線用藥。
國際預後評分系統 (International Prognostic Scoring System, IPSS) 中之高風險 (high risk) 與中等－ 2風險 (intermediate-2 risk) 屬於高危險群。對於高危險群MDS 病患，每28 天給予7 天azacitidine (75 mg/m2/day) 皮下或靜脈注射，至少給予4 ~ 6 個療程，發現可延緩進展成AML，有較高速率的完全緩解 (completeremission)、部分緩解 (partial remission)，血液學改善和對輸血較不依賴，同時可減少住院天數、降低感染、改善生活品質 (quality of life)；有隨機第三期試驗證實 azacitidine 是目前對於高危險群 MDS 或 AML ( 世界衛生組織World Health Organization, WHO 定義) 之治療，與最佳支持療法、低劑量 cytarabine、或標準化療相較，唯一可以有意義地延長總存活率之藥品。此外，為了使高危險群MDS 病患得到更穩定持久的病情控制，現在有越來越多證據表明，不同作用機制的藥物的合併療法可能提供一個潛在的好處。
 

Azacitidine had been approved by the U.S. and Taiwan Food and Drug administration (FDA) for treatment of myelodysplastic syndromes (MDS). It had demonstrated improvement in delaying progression to acute myeloblastic leukemia (AML) and increasing survival for patients with higher-risk MDS. Since azacitidine is the only hypomethylation agents (HMA) shown to prolong overall survival, most experts recommend azacitidine as first-line therapy for higher-risk MDS.
The high risk and intermediate-2 risk were classified as higher-risk MDS according to the international prognostic scoring system (IPSS). The schedule of azacitidine for MDS was subcutaneous or intravenous administration of 75 mg/m2 per day for 7 consecutive days every 28 days, at least 4 ~ 6 cycles for higher-risk MDS. The schedule was associated with delaying leukemic progression, higher rate of complete remission and partial remission, better hematologic improvement, decreased transfusions, shorter hospitalizations,
decreased infections, and maintaining quality of life. In randomized phase III trials regarding overall survival, azacitidine is superior than standard chemotherapy, best supportive care and low-dose cytarabine for higherrisk MDS significantly. Futhermore, there are many evidneces demostrating that drug combinations with different mechanisms of action may offer potential benefits for the patients with MDS of higher risks in disease control.