Acceleron’s ACE-536 Preclinical Data Presentation Selected for Best Abstract at 12th International Symposium on Myelodysplastic Syndromes

Acceleron’s ACE-536 Preclinical Data Presentation Selected for Best Abstract at 12th International Symposium on Myelodysplastic Syndromes

May 10, 2013


Acceleron Pharma, Inc., a biopharmaceutical company developing protein therapeutics for cancer and orphan hematologic diseases, today announced that preclinical research conducted by Acceleron scientists on the ACE-536 program received the Tito Bastianello Award for best abstract and oral presentation at the 12th International Symposium on Myelodysplastic Syndromes in Berlin, Germany. Acceleron presented data on the effects of its investigational protein therapeutic, ACE-536, on correcting anemia and ineffective erythropoiesis in an animal model of myelodysplastic syndromes (MDS). In a separate poster presentation, Acceleron also presented a description of its ongoing phase 2 study (“PACE-MDS”) of ACE-536 in patients with MDS. ACE-536 increases red blood cells (RBC) and hemoglobin levels through a novel mechanism distinct from that of currently available anemia therapies, such as erythropoiesis-stimulating agents. ACE-536 is being developed by Acceleron as part of a global collaboration with Celgene Corporation (CELG).

Acceleron’s oral presentation highlighted preclinical data demonstrating that ACE-536 inhibits SMAD 2/3 signaling and consequently increases levels of red blood cells (RBC) and hemoglobin by promoting the differentiation of late stage RBC precursors. ACE-536 also normalized the level of RBC precursors in the bone marrow of MDS mice, further indicating that ACE-536 may correct the ineffective erythropoiesis observed in MDS patients. In MDS patients, overactive signaling by the SMAD 2/3 pathway in the bone marrow may contribute to ineffective erythropoiesis, a defect in which red blood cell precursors in the bone marrow are prevented from maturing into healthy, functional red blood cells.

“We’re pleased to present data on the mechanistic rationale for the encouraging effects shown in this preclinical MDS model”, said Ravi Kumar, Ph.D., Chief Scientific Officer of Acceleron. “The potential of ACE-536 to correct the anemia by targeting ineffective erythropoiesis is very exciting and applicable to other diseases, such as beta thalassemia, in which ineffective erythropoiesis leads to serious and chronic anemia and where there are few treatment options.”

About Myelodysplastic Syndromes

Myelodysplastic syndromes (MDS) are a heterogeneous group of hematologic malignancies of the bone marrow commonly leading to severe and chronic anemia due to ineffective erythropoiesis. The National Cancer Institute estimates that more than 10,000 people are diagnosed with MDS in the United States each year. Patients with MDS have a hypercellular bone marrow with various dysplastic changes of the cells that are also seen in peripheral blood, resulting in cytopenias (low blood cell counts) and an increased risk of progression to acute myeloid leukemia (AML). Nearly all MDS patients suffer from anemia. The anemia in MDS is characterized by increased levels of endogenous erythropoietin (EPO) driving an abundance of early stage red blood cell precursors and an inability of these precursor cells to properly differentiate into healthy, functional red blood cells. Many patients are therefore unresponsive to the administration of erythropoietin to correct the resulting anemia and instead require red blood cell transfusions, which can increase the risk of infection and iron-overload related toxicities.

About ACE-536

ACE-536 is a modified type II activin receptor fusion protein that acts as a ligand trap for members in the TGF-β superfamily involved in erythropoiesis. ACE-536 regulates late-stage erythrocyte (red blood cell) precursor cell differentiation and maturation, distinct from erythropoietin (EPO) which stimulates the proliferation of early-stage erythrocyte precursor cells. In diseases of ineffective erythropoiesis, such as myelodysplastic syndromes (MDS) and beta-thalassemia, in which there is an over-production of early-stage erythrocyte precursors in the bone marrow, administration of EPO does not correct the underlying cause of the anemia. By promoting the differentiation of the precursor cells into mature RBCs, ACE-536 has the potential to treat the anemia in MDS and beta-thalassemia patients. In a phase 1 clinical study in healthy volunteers, ACE-536 produced dose-dependent increases in red blood cell counts and hemoglobin levels. Acceleron and Celgene are jointly developing ACE-536. ACE-536 is currently in phase 2 clinical trials in patients with beta-thalassemia and in patients with myelodysplastic syndromes. For more information, please visit

About Acceleron

Acceleron is a privately-held biopharmaceutical company committed to discover, develop, manufacture and commercialize novel protein therapeutics for orphan diseases and cancer. Acceleron’s scientific approach takes advantage of its unique insight to discover first-in-class therapies based on the TGF-β protein superfamily. Acceleron utilizes proven biotherapeutic technologies and capitalizes on the company’s internal GMP manufacturing capability to advance its therapeutic programs rapidly and efficiently. The investors in Acceleron include Advanced Technology Ventures, Alkermes, Avalon Ventures, Bessemer Ventures, Celgene, Flagship Ventures, MPM BioEquities, OrbiMed Advisors, Polaris Ventures, QVT Financial, Sutter Hill Ventures and Venrock. For further information on Acceleron, please visit


Acceleron Pharma:
Steven Ertel, 617-649-9234
Chief Business Officer
Suda Communications LLC
Maureen L. Suda, 585-387-9248