What is the recommended treatment for a patient with a myeloid neoplasm (myelodysplastic syndrome, myelodysplastic/myeloproliferative neoplasm, or acute myeloid leukemia) based on transplant eligibility and performance status?

Treatment Recommendations for Myeloid Neoplasms Based on Transplant Eligibility and Performance Status

For fit patients ≤70 years with higher-risk myelodysplastic syndrome (MDS) who have an available donor, allogeneic stem cell transplantation (allo-SCT) is the recommended treatment, with or without preceding chemotherapy or hypomethylating agents to reduce blast percentage. 1

Treatment Algorithm by Patient Category

Fit Patients ≤70 Years with Available Donor

Allo-SCT is the definitive treatment [Level I, Grade A evidence]. 1 This remains the only curative approach for MDS and should be offered to all higher-risk patients without major comorbidities who have a donor. 1, 2

• Bridge therapy considerations: Use 2-6 cycles of azacitidine before transplant to reduce bone marrow blasts or for logistical reasons (finding a donor). 1
• Alternative bridge: AML-like intensive chemotherapy can be used for patients with favorable cytogenetics (normal karyotype) and >10% marrow blasts, preferably as a bridge to allo-SCT [Level I, Grade B]. 1
• Critical caveat: Patients with unfavorable karyotype show poor complete remission rates with intensive chemotherapy and should proceed directly to transplant or use hypomethylating agents. 1

Patients >70 Years OR Younger Without Donor

Azacitidine is the first-line reference treatment [Level I, Grade A evidence]. 1 This represents the standard of care for higher-risk MDS patients not immediately eligible for allo-SCT.

Dosing specifics:

• Standard schedule: 75 mg/m²/day subcutaneously for 7 consecutive days every 28 days 1
• Alternative acceptable schedule: "5-2-2" regimen (easier to apply in practice) 1
• Minimum duration: At least 6 cycles are required before assessing efficacy, as most patients only respond after several courses 1
• Doses can be reduced in relatively frail patients 1

Evidence strength: Azacitidine demonstrated superiority over conventional care regimens (supportive care, low-dose cytarabine, and AML-like chemotherapy) in randomized trials, with survival benefit. 3 A recent randomized study showed allo-SCT with reduced-intensity conditioning was superior to hypomethylating agents for patients >50 years with higher-risk MDS. 4

Response assessment: Achievement of hematological improvement (HI) according to IWG 2006 criteria is associated with prolonged survival, not just complete or partial remission. 1

Very Frail Patients

Supportive care is the appropriate approach. 1 This includes:

• Red blood cell transfusions [Level IV, Grade A] 1
• Antibiotics for infection management
• Platelet transfusions as needed
• Consider clinical trial or symptomatic treatment if initial approach fails 1

Special Considerations for MDS/MPN Overlap Syndromes

For chronic myelomonocytic leukemia (CMML) and other MDS/MPN overlap syndromes, the same transplant-eligibility algorithm applies, with allo-SCT being the only curative option for appropriate patients. 5 Therapeutic approaches are largely borrowed from MDS treatment paradigms.

Critical Decision Points

Age cutoff: The 70-year threshold is not absolute—reduced-intensity conditioning regimens have enabled successful transplants in patients 60-70 years of age, with the number of older transplanted patients increasing over time. 4, 6

Cytogenetic risk matters: Patients with unfavorable karyotype (particularly TP53 mutations) have poor outcomes with intensive chemotherapy and should not receive AML-like treatment. 1, 4 These patients should proceed to allo-SCT if eligible or receive azacitidine.

Blast percentage threshold: For patients with >10% marrow blasts and favorable cytogenetics, reducing blast count before allo-SCT with either AML-like chemotherapy or hypomethylating agents is generally recommended, especially for non-myeloablative allo-SCT [Level III, Grade A]. 1

Common Pitfalls to Avoid

1. Stopping azacitidine too early: Do not assess treatment failure before completing at least 6 cycles, as responses are often delayed. 1

2. Using intensive chemotherapy in unfavorable cytogenetics: This leads to poor complete remission rates and shorter remission duration without survival benefit. 1

3. Overlooking transplant candidacy in older patients: With reduced-intensity conditioning, patients up to 70 years (and sometimes beyond) can successfully undergo allo-SCT. 4, 6

4. Delaying transplant evaluation: For any fit patient ≤70 years, donor search should begin at diagnosis of higher-risk disease, as allo-SCT remains the only curative option. 1, 2