In a patient with low‑risk myelodysplastic syndrome and anemia, should erythropoiesis‑stimulating agents (ESA) be used as marrow‑stimulating injections to increase red blood cell production?

Erythropoiesis-Stimulating Agents for Low-Risk MDS Anemia

Yes, erythropoiesis-stimulating agents (ESAs), particularly epoetin alfa, should be used as first-line treatment for anemia in patients with low-risk myelodysplastic syndrome who do not have del(5q) chromosomal abnormality. 1

First-Line Treatment Algorithm

For patients WITHOUT del(5q):

• ESAs (epoetin alfa or darbepoetin alfa) are the recommended first-line therapy when serum erythropoietin (EPO) level is ≤200-500 U/L 1
• Dosing: EPO 30,000-80,000 units weekly OR darbepoetin 150-300 mcg weekly 1
• Expected response rate: 40-60% when baseline EPO is low and transfusion requirement is absent or limited 1
• Response occurs within 8-12 weeks of treatment 1
• Median duration of response: 20-24 months 1

For patients WITH del(5q):

• Lenalidomide is the most effective first-line drug (60-65% response rate), NOT ESAs 1
• ESAs have lower response rates and shorter duration in del(5q) patients 1

Key Predictive Factors for ESA Response

The two main prognostic factors that determine ESA success are:

1. Low baseline serum EPO level (<200-500 U/L)
2. Low or absent transfusion requirement at baseline 1

Patients meeting both criteria have the highest likelihood of achieving erythroid response.

Enhancing ESA Efficacy

Adding G-CSF (granulocyte colony-stimulating factor) to ESAs improves efficacy 1, though this combination approach is used selectively based on individual response.

Important Clinical Benefits Beyond Anemia Correction

ESA treatment is an independent favorable prognostic factor for survival 1. The EUMDS registry demonstrated that ESA treatment was associated with:

• Nonsignificant survival benefit (HR 0.82) 2
• Significant delay in onset of regular transfusion need, particularly in non-transfused patients (median 23.3 months vs 6.1 months in previously transfused patients) 2
• Responding patients had lower risk of death (HR 0.65) 2

Critically, receiving ESAs has no impact on progression to acute myeloid leukemia 1, addressing a common safety concern.

Second-Line Options After ESA Failure

When ESAs fail, the treatment pathway depends on specific disease characteristics:

For MDS with ring sideroblasts (RS ≥15% or RS ≥5% with SF3B1 mutation):

• Luspatercept is recommended 1
• Imetelstat (recently FDA-approved) for patients with serum EPO >500 mU/mL who are ineligible for ESAs 3, 4
  • Achieved 40% RBC transfusion independence ≥8 weeks vs 15% placebo 4
  • Dosing: 7.1 mg/kg IV monthly with potential dose decrements 3
  • Warning: Frequent transient thrombocytopenia (62%) and neutropenia (68%) occur; starting platelets must be ≥75,000 and neutrophils ≥1,500 3

For other ESA-refractory cases:

• Lenalidomide ± ESA 1
• Hypomethylating agents (HMAs) 1
• Immunosuppressive therapy (ATG ± cyclosporine) in younger patients with specific characteristics 1

Critical Caveats

1. Only epoetin alfa (and biosimilars) is formally approved by the EMA for lower-risk MDS with serum EPO <200 U/L 1

2. Iron overload management: Patients receiving chronic RBC transfusions require iron chelation when ferritin rises above 1000-2500 U/L or after 20-60 RBC units 1

3. Disease reclassification: If initially managed as lower-risk MDS but fails to respond to ESAs, consider moving to higher-risk management strategies 3

4. Quality of life: ESAs not only improve hemoglobin but also significantly improve quality of life compared to transfusion-only strategies 1

5. Avoid ESAs when serum EPO >500 mU/mL - response rates are poor; consider alternative agents like imetelstat or luspatercept instead 1, 3