Acceleron Announces Closing of Underwriters’ Option to Purchase Additional Shares

CAMBRIDGE, Mass.--()--Acceleron Pharma Inc. (NASDAQ: XLRN), a leading biopharmaceutical company in the discovery and development of TGF-beta therapeutics to treat serious and rare diseases, today announced that it has issued 810,810 shares of common stock at the public offering price of $37.00 per share, pursuant to the full exercise of the underwriters’ over-allotment option in connection with the Company’s previously announced public offering of common stock. The aggregate net proceeds to the Company of the public offering, including the full exercise of the over-allotment option and after deducting underwriting discounts and commissions and other estimated offering expenses, were approximately $215.8 million.

J.P. Morgan Securities LLC, Citigroup and Leerink Partners LLC acted as joint book-running managers for the offering.

The shares were offered by Acceleron pursuant to an effective shelf registration statement on Form S-3 that was previously filed with the Securities and Exchange Commission (the “SEC”). A preliminary prospectus supplement relating to and describing the terms of the offering was filed with the SEC on September 19, 2017. The final prospectus supplement relating to the offering was filed with the SEC on September 21, 2017. Copies of the final prospectus supplement and the accompanying prospectus can be obtained at the SEC’s website http://www.sec.gov or from J.P. Morgan Securities LLC, Attention: Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, NY 11717, telephone: 1-866-803-9204 or email: prospectus-eq_fi@jpmchase.com; Citigroup Global Markets Inc., c/o Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, NY 11717 or telephone: 1-800-831-9146; and Leerink Partners LLC, Attention: Syndicate Department, One Federal Street, 37th Floor, Boston, MA, 02110, or by e-mail at Syndicate@Leerink.com, or by phone at 800-808-7525, ext. 6132.

This press release does not constitute an offer to sell or a solicitation of an offer to buy the securities in the offering, nor shall there be any sale of these securities in any jurisdiction in which an offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of such jurisdiction.

About Acceleron

Acceleron is a leading biopharmaceutical company in the discovery and development of TGF-beta therapeutics to treat serious and rare diseases. Its pioneering research and protein engineering platform engages the target-rich TGF-beta superfamily and its remarkable ability to regulate cellular growth and repair.

Under a global partnership with Celgene, Acceleron is in Phase 3 development with luspatercept, a potential first-in-class chronic anemia therapy for the treatment of rare blood diseases. The Company is also advancing a neuromuscular franchise with two distinct Myostatin+ agents, ACE-083 and ACE-2494, and a pulmonary program with a Phase 2 trial of sotatercept planned in pulmonary arterial hypertension. Acceleron has ongoing preclinical research efforts targeting additional indications in these three disease areas where there is significant unmet medical need.

Cautionary Note on Forward-Looking Statements

Certain statements contained in this release are forward-looking statements that involve a number of risks and uncertainties that could cause actual results to differ materially from those in the forward-looking statements. These risks and uncertainties include, but are not limited to, risks and uncertainties associated with the consummation of the proposed offering and general economic conditions and other risks identified from time to time in the reports we file with the SEC, including our Annual Report on Form 10-K, Quarterly Reports on Form 10-Q, and Current Reports on Form 8-K, which are available at www.sec.gov. We caution investors not to place considerable reliance on the forward-looking statements contained in this press release. The forward-looking statements in this press release speak only as of the date of this document, and we undertake no obligation to update or revise any of the statements. Our business is subject to substantial risks and uncertainties, including those referenced above. Investors, potential investors, and others should give careful consideration to these risks and uncertainties.

Contacts

Investors:
Acceleron Pharma
Todd James, 617-649-9393
Vice President, Investor Relations and Corporate Communications
or
Media:
BMC Communications
Brad Miles, 917-570-7340
Bmiles@bmccommunications.com

Contacts

Investors:
Acceleron Pharma
Todd James, 617-649-9393
Vice President, Investor Relations and Corporate Communications
or
Media:
BMC Communications
Brad Miles, 917-570-7340
Bmiles@bmccommunications.com