Acceleron Pharma Reports Second Quarter 2015 Financial and Operational Results

- Completed luspatercept myelodysplastic syndromes phase 2 clinical trial -

- FDA Fast Track Designations granted to luspatercept for the treatment of patients with beta-thalassemia -

- Phase 3 clinical trials with luspatercept in lower risk myelodysplastic syndromes and beta-thalassemia expected to begin by year-end 2015 -

CAMBRIDGE, Mass.--(BUSINESS WIRE)-- Acceleron Pharma Inc. (NASDAQ:XLRN), a clinical stage biopharmaceutical company focused on the discovery, development and commercialization of novel therapeutic candidates that regulate cellular growth and repair, today provided a corporate update and reported financial results for the second quarter ended June 30, 2015.

"In the second quarter, we presented promising new longer-term treatment data from our luspatercept programs. These results further reinforce our excitement about the potential of luspatercept to help patients with myelodysplastic syndromes and beta-thalassemia. We and our collaboration partner, Celgene, look forward to starting pivotal trials in both of these indications by the end of this year," said John Knopf, Ph.D., Chief Executive Officer of Acceleron. "At Acceleron, we remain focused on bringing innovative therapies to patients, and we are continuing to advance and expand our earlier stage pipeline as well. We have scheduled our first Research and Development Day for investors on October 23, 2015. At that meeting, we will review our clinical and preclinical programs, including a first look at top-line data from the phase 1 trial with our candidate muscle agent, ACE-083."

Recent Highlights and Current Updates

Development Programs

Hematology

Oncology

Muscle Diseases

Upcoming Milestones and Events

Financial Results

Cash Position - Cash, cash equivalents and investments as of June 30, 2015 were $156.6 million. As of December 31, 2014 the company had cash and cash equivalents of $176.5 million. Acceleron expects that its cash, cash equivalents and investments as of June 30, 2015 will be sufficient to fund the Company's operations into the second half of 2017.

Conference Call and Webcast

The company will host a conference call and live audio webcast to report its second quarter financial results for 2015 and provide a corporate update on August 6, 2015, at 8:00 AM EDT. To participate by teleconference, please dial 877-312-5848 (domestic) or 253-237-1155 (international) and refer to the "Acceleron Q2 Earnings Call." To access the live webcast, please select "Events & Presentations" in the Investors & Media section on the Company's website (www.acceleronpharma.com) at least 10 minutes beforehand to ensure time for any downloads that may be required. An archived webcast recording will be available on the Acceleron website beginning approximately two hours after the event.

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-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 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.