Luspatercept increased hemoglobin levels and generated transfusion independence in patients with lower risk myelodysplastic syndromes

SUMMIT, NJ & CAMBRIDGE, MA, USA I December 6, 2015 I Celgene Corporation (NASDAQ:CELG) and Acceleron Pharma Inc. (NASDAQ:XLRN) today announced preliminary results from an ongoing long-term Phase 2 extension study in patients with lower risk myelodysplastic syndromes (MDS) at the 57th American Society of Hematology (ASH) Annual Meeting and Exposition. Results highlighted in an oral presentation showed that patients with lower risk MDS treated with luspatercept in the long-term extension study achieved and maintained increased hemoglobin levels and transfusion independence. Celgene and Acceleron are jointly developing luspatercept.

“These results for longer-term luspatercept treatment in lower risk MDS patients are very exciting,” said Aristoteles Giagounidis, M.D., Ph.D., Head of the Department of Oncology, Haematology, and Palliative Care at Marien Hospital in Düsseldorf, Germany. “There is substantial unmet medical need for patients who do not respond or become refractory to treatment with erythropoiesis stimulating agents or who are considered ineligible to receive them. Luspatercept has shown very encouraging activity in these patients which provides the basis for the Phase 3 MEDALIST study.”

Luspatercept Data Presented at ASH

A total of 32 low- or intermediate-1 risk MDS patients were treated with luspatercept in this long-term 24-month open-label extension study. Luspatercept was administered subcutaneously once every 3 weeks at a starting dose level of 1.0 mg/kg. The dose level could be increased to 1.75 mg/kg. Of these 32 patients, 13 had a low transfusion burden (<4 units RBC/8 weeks) and 19 had a high transfusion burden (≥4 units RBC/8 weeks). 59% of patients had been treated previously with erythropoiesis stimulating agents (ESA) and 19% of patients had previously been treated with lenalidomide. 91% of the patients were ring sideroblast positive (more than 15% of erythroid cells in the bone marrow were ring sideroblasts).

Patients who were refractory or intolerant to prior ESA treatment

  • 63% (12 of 19) of HTB and LTB patients with prior ESA treatment achieved an International Working Group (IWG) Hematologic Improvement Erythroid (HI-E) response of a reduction of ≥4 units RBC over 8 weeks or a hemoglobin increase ≥1.5 g/dL for ≥8 weeks during their luspatercept treatment period
  • 50% (7 of 14) achieved transfusion independence

Patients who are considered ESA ineligible because they had elevated erythropoietin levels between 200 and 500 U/L

  • 71% (5 of 7) achieved an HI-E response and 50% (2 of 4) achieved transfusion independence

High Transfusion Burden (HTB) Patients

  • 68% (13 of 19) of the HTB patients achieved the IWG HI-E criteria of a reduction of ≥4 units RBC over 8 weeks
  • 42% (8 of 19) of the HTB patients achieved transfusion independence for ≥8 weeks

Low Transfusion Burden (LTB) Patients

  • 69% (9 of 13) of the LTB patients achieved the IWG HI-E response criteria of a hemoglobin increase ≥1.5 g/dL for ≥8 weeks
  • The mean increase in hemoglobin reached levels between 2.0 and 2.5 g/dL and was maintained for the 9 months for which data are available

Safety

  • Adverse events at least possibly related to study drug that occurred in patients during the extension study included bone pain, headache, hypotonia, myalgia and nausea. No serious or grade 3 or 4 adverse events related to study drug have been reported during the ongoing extension study.

Celgene and Acceleron are in the process of initiating a global Phase 3 study in low risk, ring sideroblast positive MDS patients.

Luspatercept is an investigational product that is not approved for any use in any country.

About Luspatercept

Luspatercept is a modified activin receptor type IIB fusion protein that acts as a ligand trap for members in the Transforming Growth Factor-Beta (TGF-β) superfamily involved in the late stages of erythropoiesis (red blood cell production). Luspatercept regulates late-stage erythrocyte (red blood cell) precursor cell differentiation and maturation. This mechanism of action is distinct from that of erythropoietin (EPO), which stimulates the proliferation of early-stage erythrocyte precursor cells. Acceleron and Celgene are jointly developing luspatercept as part of a global collaboration. For more information, please visit www.clinicaltrials.gov.

About Acceleron

Acceleron is a clinical stage biopharmaceutical company focused on the discovery, development and commercialization of novel therapeutic candidates that regulate cellular growth and repair. The company is a leader in understanding the biology of the Transforming Growth Factor-Beta (TGF-β) protein superfamily, a large and diverse group of molecules that are key regulators in the growth and repair of tissues throughout the human body, and in targeting these pathways to develop important new medicines. Acceleron has built a highly productive R&D platform that has generated innovative clinical and preclinical therapeutic candidates with novel mechanisms of action. These therapeutic candidates have the potential to significantly improve clinical outcomes for patients with cancer and rare diseases.

For more information, please visit www.acceleronpharma.com.

About Celgene

Celgene Corporation, headquartered in Summit, New Jersey, is an integrated global pharmaceutical company engaged primarily in the discovery, development and commercialization of innovative therapies for the treatment of cancer and inflammatory diseases through gene and protein regulation. For more information, please visit the Company’s website at www.celgene.com. Follow us on Twitter @Celgene as well.

SOURCE: Celgene