We are investigating possible breaches of fiduciary duty and other violations of law by the board of directors of Acceleron Pharma Inc. (“Acceleron” or the “Company”) (NASDAQ: XLRN) in connection with the proposed acquisition of the Company by Merck & Co., Inc. (“Merck”) (NYSE: MRK), via a tender offer.  Under the terms of the merger agreement, the Company’s shareholders will receive $180.00 per share in cash for each share of Acceleron common stock that they hold.  The transaction is valued at approximately $11.5 billion.

WeissLaw LLP is investigating whether (i) Acceleron’s board of directors acted in the best interests of Company shareholders in agreeing to the proposed transaction, (ii) the $180.00 per-share offer price adequately compensates Acceleron’s shareholders, and (iii) all information regarding the sales process and valuation of the transaction will be fully and fairly disclosed.  Notably, a financial analyst set a $183.00 price target for the Company’s stock, $3.00 above the offer price.