Acceleron Receives FDA Orphan Drug Designation for ACE-1334 for the Treatment of Systemic Sclerosis

– Company plans to initiate Phase 1b/Phase 2 trial in patients with systemic sclerosis-associated interstitial lung disease (SSc-ILD) in 2021 –

– ACE-1334 previously received Fast Track designation from the FDA –

CAMBRIDGE, Mass.--()--Acceleron Pharma Inc. (Nasdaq: XLRN), a biopharmaceutical company dedicated to the discovery, development, and commercialization of TGF-beta superfamily therapeutics to treat serious and rare diseases, today announced that the United States Food and Drug Administration (FDA) has granted Orphan Drug designation to ACE-1334 for the treatment of patients with systemic sclerosis. The Company intends to initiate a Phase 1b/Phase 2 trial in patients with systemic sclerosis-associated interstitial lung disease (SSc-ILD) in 2021.

“We’re excited that ACE-1334 has received Orphan Drug designation, as it aligns with our vision to develop novel therapies for pulmonary diseases of high unmet medical need,” said Habib Dable, President and Chief Executive Officer of Acceleron. “It’s clear that 2021 will be an important year in this regard, as we seek to expand our portfolio in this important therapeutic area. In addition to advancing our Phase 3 clinical program to investigate sotatercept’s potential to reverse vascular remodeling associated with pulmonary arterial hypertension, we’re pleased to be planning for a Phase 1b/Phase 2 study to determine whether the anti-fibrotic activity ACE-1334 has demonstrated in preclinical models of fibrosis can be replicated in patients with SSc-ILD.”

Orphan designation is granted by the FDA Office of Orphan Products Development to advance the evaluation and development of safe and effective therapies for the treatment of rare diseases or conditions affecting fewer than 200,000 people in the U.S. Under the Orphan Drug Act, the FDA may provide grant funding toward clinical trial costs, tax advantages, FDA user-fee benefits, and seven years of market exclusivity in the United States following marketing approval by the FDA. The granting of an orphan designation request does not alter the standard regulatory requirements and process for obtaining marketing approval. For more information about orphan designation, please visit the FDA website.

ACE-1334 is an investigational therapy that is not approved for any use in any country.

About ACE-1334

ACE-1334 is an Acceleron-discovered, TGF-beta superfamily-based ligand trap designed to bind and inhibit TGF-beta 1 and 3 ligands but not TGF-beta 2. TGF-beta 1 and 3 are believed to be key signaling factors in the pathogenesis of fibrotic disease. ACE-1334 has shown robust anti-fibrotic activity in multiple preclinical models of fibrosis. ACE-1334 recently completed an ascending-dose Phase 1 clinical trial in healthy volunteers. The FDA has granted Fast Track designation to ACE-1334 in patients with systemic sclerosis-associated interstitial lung disease (SSc-ILD) as well as Orphan Drug designation for the treatment of systemic sclerosis.

About SSc-ILD

Systemic sclerosis-associated interstitial lung disease (SSc-ILD; also known as systemic scleroderma-associated interstitial lung disease) is a rare, progressive, autoimmune connective tissue disorder characterized by immune dysregulation. It is reported to be the most common cause of death among patients with systemic scleroderma. Patients with SSc-ILD ultimately experience severely compromised pulmonary function, with the disease initially causing cough, shortness of breath, and fatigue. SSc-ILD, which affects an estimated 50,000 patients in the United States and Europe, is thought to arise from a combination of genetic susceptibility, autoimmunity, inflammation, fibrotic activity, and vascular insult. The disease has an estimated 10-year survival rate of approximately 56%. Current treatment for SSc-ILD includes a range of potentially high-risk approaches, including immunosuppression, hematopoietic stem cell transplantation, and lung transplantation.

About Acceleron

Acceleron is a biopharmaceutical company dedicated to the discovery, development, and commercialization of therapeutics to treat serious and rare diseases. Acceleron’s leadership in the understanding of TGF-beta superfamily biology and protein engineering generates innovative compounds that engage the body's ability to regulate cellular growth and repair.

Acceleron focuses its research, development, and commercialization efforts in pulmonary and hematologic diseases. In pulmonary, Acceleron is developing sotatercept for the treatment of pulmonary arterial hypertension (PAH), having reported positive topline results of the PULSAR Phase 2 trial. The Company is currently planning multiple Phase 3 trials with the potential to support its long-term vision of establishing sotatercept as a backbone therapy for patients with PAH at all stages of the disease. Acceleron is also investigating the potential of its early-stage pulmonary candidate, ACE-1334, which it plans to advance into a Phase 1b/Phase 2 trial in systemic sclerosis-associated interstitial lung disease (SSc-ILD) next year.

In hematology, REBLOZYL® (luspatercept-aamt) is the first and only erythroid maturation agent approved in the United States, Europe, and Canada for the treatment of anemia in certain blood disorders. REBLOZYL is part of a global collaboration partnership with Bristol Myers Squibb. The Companies co-promote REBLOZYL in the United States and are also developing luspatercept for the treatment of anemia in patient populations of myelodysplastic syndromes, beta-thalassemia, and myelofibrosis.

For more information, please visit www.acceleronpharma.com. Follow Acceleron on Social Media: @AcceleronPharma and LinkedIn.

Forward-Looking Statements

This press release contains forward-looking statements about Acceleron’s strategy, future plans and prospects, including statements regarding the development of ACE-1334, and the potential of Acceleron’s compounds as therapeutic drugs. The words "anticipate," "believe," "could," "estimate," "expect," "goal," "intend," "may," "plan," “possible,” "potential," "project," "should," "target," "will," "would," and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words.

Actual results could differ materially from those included in the forward-looking statements due to various factors, risks and uncertainties, including, but not limited to, 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 regulatory approval of Acceleron’s compounds in one indication or country may not be predictive of approval in another indication or country, that the development of Acceleron’s compounds will take longer and/or cost more than planned, that Acceleron will be unable to successfully complete the clinical development of Acceleron’s compounds, that Acceleron may be delayed in initiating, enrolling or completing any clinical trials, and that Acceleron’s compounds will not receive regulatory approval or become commercially successful products. These and other risks and uncertainties are identified under the heading “Risk Factors” included in Acceleron’s most recent Annual Report on Form 10-K, Quarterly Reports on Form 10-Q, 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 are based on management's current views, plans, estimates, assumptions, and projections with respect to future events, and Acceleron does not undertake and specifically disclaims any obligation to update any forward-looking statements.

Contacts

Acceleron Pharma Inc.

Investors:
Jamie Bernard, IRC, 617-649-9650
Associate Director, Investor Relations

Media:
Matt Fearer, 617-301-9557
Director, Corporate Communications

Contacts

Acceleron Pharma Inc.

Investors:
Jamie Bernard, IRC, 617-649-9650
Associate Director, Investor Relations

Media:
Matt Fearer, 617-301-9557
Director, Corporate Communications