Clinical Scorecard: Efficacy of Azacitidine in Patients with Transfusion-Dependent, Growth Factor-Resistant Low- and Intermediate-1-Risk MDS: Findings from the Nordic NMDSG08A Phase II Study

At a Glance

Key Highlights

• Anemia is the predominant symptom in low- and intermediate-1-risk MDS, with about 50% responding to ESA treatment.
• Patients refractory to ESA with transfusion needs ≥2 units/4 weeks and serum erythropoietin >500 U/l have low response rates (~7%) and require alternative therapies.
• Azacitidine demonstrated limited overall efficacy and considerable toxicity in ESA-resistant, transfusion-dependent lower-risk MDS patients in this phase II trial.

Guideline-Based Recommendations

Diagnosis

• Diagnosis based on IPSS risk stratification (low or intermediate-1), bone marrow morphology, and transfusion dependence.
• Use of predictive model incorporating serum erythropoietin levels and transfusion rate to assess ESA response probability.

Management

• For ESA-resistant, transfusion-dependent patients, azacitidine monotherapy (75 mg/m2 daily for 5 days every 28 days) administered for six cycles.
• Addition of erythropoietin beta (60,000 units/week) after six cycles if transfusion dependence persists.
• Dose adjustments or temporary discontinuation of azacitidine in case of severe hematological or non-hematological toxicity.
• Use of G-CSF allowed during treatment as clinically indicated.

Monitoring & Follow-up

• Assessment of transfusion independence after six and nine cycles of treatment.
• Regular monitoring of blood counts and toxicity grading per NCI CTC version 3.0.
• Bone marrow morphology and cytogenetics evaluated at baseline, week 28, and week 45.
• Monitoring for hematological toxicity with thresholds for ANC and platelet counts guiding dose modifications.

Risks

• Considerable toxicity associated with azacitidine, including cytopenias requiring dose adjustments.
• Potential worsening of quality of life due to transfusion dependence if treatment is ineffective.
• Risk of progression to acute myeloid leukemia inherent to MDS.

Patient & Prescribing Data

Adults with low- or intermediate-1-risk MDS, transfusion-dependent and refractory to ESA treatment.

Azacitidine showed limited efficacy in inducing transfusion independence in this population, with an overall response rate lower than previously reported in non-ESA-resistant cohorts; toxicity was significant, necessitating careful patient selection and monitoring.

Clinical Best Practices

• Use predictive models incorporating serum erythropoietin and transfusion rates to identify ESA resistance before initiating azacitidine.
• Administer azacitidine at 75 mg/m2 for 5 consecutive days every 28 days for six cycles, with evaluation of transfusion independence.
• Add erythropoietin beta after six cycles if transfusion dependence persists to potentially enhance response.
• Monitor hematologic parameters closely and adjust azacitidine dosing or delay cycles in case of severe toxicity.
• Employ G-CSF support as needed to manage neutropenia during treatment.
• Perform bone marrow assessments at baseline and during treatment to evaluate morphological and cytogenetic changes.

References

• ClinicalTrials.gov NCT01048034