Merck Announces Expiration of Hart-Scott-Rodino Act Waiting Period and Extension of Tender Offer to Acquire Acceleron Pharma Inc.

KENILWORTH, N.J.-- Merck (NYSE: MRK), known as MSD outside the United States and Canada, today announced that the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended (“HSR”), in connection with Merck’s pending acquisition of Acceleron Pharma Inc. (Nasdaq: XLRN) expired at 11:59 p.m., Eastern Time, on Nov. 16, 2021.

As previously announced on Oct. 12, 2021, Merck commenced, through a subsidiary, Astros Merger Sub, Inc., a cash tender offer to purchase all outstanding shares of common stock of Acceleron, for $180 in cash, without interest and less any required tax withholding. The expiration of the HSR waiting period satisfies one of the conditions necessary for the consummation of the tender offer. Consummation of the tender offer remains subject to other conditions described in the tender offer statement on Schedule TO filed with the U.S. Securities and Exchange Commission (the “SEC”) on Oct. 12, 2021, including the tender of shares representing at least a majority of the total number of Acceleron’s outstanding shares.

Astros Merger Sub, Inc. is extending the tender offer, which was previously scheduled to expire at 5:00 p.m., Eastern Time, on Nov. 18, 2021, until 5:00 p.m., Eastern time, on Nov. 19, 2021 in order to accommodate tendering of Acceleron shares traded on Nov. 17, 2021. The tender offer may be extended further in accordance with the merger agreement and the applicable rules and regulations of the SEC. All other terms and conditions of the tender offer will remain unchanged during the extended period. The acquisition is expected to close in the fourth quarter of 2021.

The Depositary for the tender offer is Computershare Trust Company, N.A., c/o Voluntary Corporate Actions, P.O. Box 43011, Providence, RI 02940-3011. The Depositary has advised Merck that, as of 5:00 p.m., Eastern time, on Nov. 16, 2021, the last business day prior to the announcement of the extension of the tender offer, approximately 11,980,722 shares of Acceleron had been validly tendered and received, and not validly withdrawn, pursuant to the tender offer, representing approximately 19.6% of Acceleron’s outstanding shares. Stockholders who have already tendered their shares do not need to retender such shares or take any other action as a result of the extension of the tender offer.

The Information Agent for the tender offer is Innisfree M&A Incorporated, 501 Madison Avenue, 20th floor, New York, NY 10022. The tender offer materials may be obtained at no charge by directing a request by mail to Innisfree M&A Incorporated or by calling toll free at (877) 800-5195, and may also be obtained at no charge at the website maintained by the SEC at www.sec.gov.