August 27, 2013 (Shareholders Foundation) - An investigation on behalf of investors who currently hold shares of Onyx Pharmaceuticals, Inc. (NASDAQ:ONXX), was announced concerning whether the takeover of Onyx Pharmaceuticals, Inc. by Amgen for $125 per NASDAQ:ONXX share is unfair to NASDAQ:ONXX stockholders.

The investigation by a law firm concerns whether a potential takeover would be unfair to Onyx Pharmaceuticals investors.

On Jun. 30, 2013, Onyx Pharmaceuticals, Inc. (Nasdaq: ONXX) confirmed that it has received and rejected an unsolicited proposal from Amgen Inc. to acquire all of Onyx Pharmaceuticals outstanding shares and share equivalents for $120 per share in cash, subject to due diligence and other conditions. On Aug. 25, 2013, Amgen (NASDAQ:AMGN) and Onyx Pharmaceuticals, Inc. (NASDAQ:ONXX) announced that their Boards of Directors have unanimously approved a transaction under which Amgen will acquire all of the outstanding shares of Onyx Pharmaceuticals, Inc. for $125 per share in cash.

However, given that NASDAQ:ONXX shares jumped after the June 30, 2013 announcement in the open market to $136.03 per share on July 5, 2013,the investigation a law firm concerns whether the $125-offer is too low and unfair to NASDAQ:ONXX stockholders. More specifically, the investigation concerns whether the Onyx Pharmaceuticals Board of Directors undertook an adequate sales process, adequately shopped the company before entering into the transaction, maximized shareholder value by negotiating the best price, and acted in the shareholders' best interests in connection with the proposed sale.

On August 27, 2013, NASDAQ:ONXX shares closed at $123.36 per share.