Erythropoiesis-stimulating agents are effective in myelodysplastic syndromes, but are they safe?

Patterns of erythropoiesis-stimulating agent use among Medicare beneficiaries with myelodysplastic syndromes and consistency with clinical guidelines

Erythropoiesis-stimulating agents (ESA) are used commonly to reduce symptomatic anemia in patients with myelodysplastic syndromes (MDS). We assessed population-based patterns of ESA use relative to treatment guidelines using data from the Surveillance, Epidemiology, and End Results (SEER) registries, with linked Medicare claims providing detailed treatment data from 2001 through 2005. The study found widespread use (62%) of ESA in Medicare beneficiaries with MDS. Similar ESA use rates regardless of risk status, low frequency (45%) of serum erythropoietin determination prior to ESA initiation, and high prevalence (60.4%) of short-duration ESA episodes suggest clinically important discrepancies between actual practice and guideline-recommended therapy.

Hypoxic regulation of erythropoiesis and iron metabolism

The kidney is a highly sensitive oxygen sensor and plays a central role in mediating the hypoxic induction of red blood cell production. Efforts to understand the molecular basis of oxygen-regulated erythropoiesis have led to the identification of erythropoietin (EPO), which is essential for normal erythropoiesis and to the purification of hypoxia-inducible factor (HIF), the transcription factor that regulates EPO synthesis and mediates cellular adaptation to hypoxia. Recent insights into the molecular mechanisms that control and integrate cellular and systemic erythropoiesis-promoting hypoxia responses and their potential as a therapeutic target for the treatment of renal anemia are discussed in this review.

Novel approaches for myelodysplastic syndromes: beyond hypomethylating agents

PURPOSE OF REVIEW

Several novel therapeutic approaches exist for treatment of patients with myelodysplastic syndrome, with goals to improve quality of life and prolong survival. This review highlights new therapies from the last 18 months.

RECENT FINDINGS

Immunosuppressants, erythropoiesis-stimulating agents in combination with granulocyte colony-stimulating factor or all-trans-retinoic-acid have shown improvement in decreasing the need for transfusions and improving quality-of-life and/or survival. Eltrombopag has shown promising results in the treatment of thrombocytopenia. However, determination of an optimal chemotherapeutic approach remains elusive and controversial. DNA methyltransferase inhibitors are well tolerated in outpatient settings, with azacitidine prolonging survival and decreasing time to acute myeloid leukemia progression in patients with high-risk myelodysplastic syndromes. A novel erythroid-specific gene expression profile may predict response to lenalidomide in patients who lack the deletion of 5q31.1. Tools such as the Charlson comorbidity index may help select appropriate patients for allogeneic stem cell transplant. A variety of promising new agents are under investigation.

SUMMARY

This review focuses on recent advances in new strategies and targeted therapies for treatment of myelodysplastic syndrome.