FDA Fast Track Designation Granted to Luspatercept for the Treatment of Patients with Beta-Thalassemia

SUMMIT, N.J. & CAMBRIDGE, Mass.--Celgene Corporation (NASDAQ:CELG) and Acceleron Pharma Inc. (NASDAQ:XLRN) today announced that the United States Food and Drug Administration (FDA) has granted Fast Track designations to luspatercept for two separate indications; the use of luspatercept for the treatment of patients with transfusion dependent beta-thalassemia and the use of luspatercept for the treatment of patients with non-transfusion dependent beta-thalassemia. Celgene and Acceleron are jointly developing luspatercept.

The Fast Track program of the FDA is designed to facilitate the development and expedite the review of new drugs that are intended to treat serious or life-threatening conditions and that demonstrate the potential to address unmet medical needs. The designation also provides the opportunity for more frequent interaction with FDA over the course of the development program, and allows a sponsor to submit sections of the BLA on a rolling basis as they are finalized.

"The FDA's Fast Track designation for the luspatercept development program recognizes the serious unmet medical needs of patients with beta-thalassemia and the potential for luspatercept in this area," said Jacqualyn A. Fouse, President, Hematology/Oncology for Celgene. "Celgene and Acceleron are working diligently to initiate a phase 3 clinical program in 2015 to treat patients with beta-thalassemia and we look forward to continuing to work closely with health authorities and other important stakeholders to advance this program."

About Luspatercept

Luspatercept is a modified activin receptor type IIB fusion protein that acts as a ligand trap for members of the Transforming Growth Factor-Beta (TGF-beta) 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. Luspatercept is currently in phase 2 clinical trials in patients with beta-thalassemia and in patients with myelodysplastic syndromes. For more information, please visit www.clinicaltrials.gov.

About Beta-thalassemia

Beta-thalassemia is an inherited disease involving mutations in the beta globin gene leading to deficient hemoglobin levels and defective red blood cell (RBC) production in the bone marrow known as ineffective erythropoiesis. Beyond the severe anemia, many patients also suffer from multiple organ dysfunction, largely due to excess iron deposits, known as "iron overload," resulting from the ineffective erythropoiesis as well as the repeated RBC transfusions to address the anemia. Iron overload can lead to heart failure, liver fibrosis, and diabetes, among other consequences. Current clinical management for beta-thalassemia includes RBC transfusions and iron chelation therapy, which is associated with toxicities. There are no drugs approved to treat beta-thalassemia leaving healthcare providers with few options for patients.

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 TGF-beta 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 protein 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.

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 www.celgene.com. Follow Celgene on Social Media: @CelgenePinterestLinkedIn and YouTube.

Forward-Looking Statements

Acceleron:

Cautionary Note on Forward-Looking Statements

This press release includes forward-looking statements about Acceleron's strategy, future plans and prospects, including statements regarding the development of luspatercept and Acceleron's TGF-beta superfamily program generally, the timeline for clinical development and regulatory approval of luspatercept, the expected timing for the reporting of data from ongoing trials, and the structure of Acceleron's planned or pending clinical trials. Each forward-looking statement is subject to risks and uncertainties that could cause actual results to differ materially from those expressed or implied in such statement. Applicable risks and uncertainties include that preclinical testing of Acceleron's compounds and data from clinical trials may not be predictive of the results or success of ongoing or later clinical trials, that data may not be available when we expect it to be, that Acceleron or Celgene will be unable to successfully complete the clinical development of its compounds, that the development of Acceleron's compounds will take longer or cost more than planned, that Acceleron or Celgene may be delayed in initiating or completing any clinical trials, and that Acceleron's compounds will not receive regulatory approval or become commercially successful products. Other risks and uncertainties include those identified under the heading "Risk Factors" included in Acceleron's Annual Report on Form 10-K which was filed with the Securities and Exchange Commission (SEC) on March 2, 2015, and other filings that Acceleron has made and may make with the SEC in the future. The forward-looking statements contained in this press release reflect Acceleron's current views with respect to future events, and Acceleron does not undertake and specifically disclaims any obligation to update any forward-looking statements.

Celgene:

This press release contains forward-looking statements, which are generally statements that are not historical facts. Forward-looking statements can be identified by the words "expects," "anticipates," "believes," "intends," "estimates," "plans," "will," "outlook" and similar expressions. Forward-looking statements are based on management's current plans, estimates, assumptions and projections, and speak only as of the date they are made. We undertake no obligation to update any forward-looking statement in light of new information or future events, except as otherwise required by law. Forward-looking statements involve inherent risks and uncertainties, most of which are difficult to predict and are generally beyond our control. Actual results or outcomes may differ materially from those implied by the forward-looking statements as a result of the impact of a number of factors, many of which are discussed in more detail in our Annual Report on Form 10-K and our other reports filed with the Securities and Exchange Commission.

Contacts

Acceleron:
Investors:
Kevin McLaughlin, 617-649-9204
Chief Financial Officer
or
Media:
Suda Communications LLC
Maureen L. Suda, 585-387-9248
or
Celgene:
Investors:
908-673-9628
[email protected]
or
Media:
908-673-2275
[email protected]