Shareholder Rights Law Firm Johnson & Weaver, LLP is investigating whether members of the board of directors of Optimer Pharmaceuticals, Inc. (NasdaqGS: OPTR) breached their fiduciary duties in connection with the proposed acquisition by Cubist Pharmaceuticals, Inc.

On July 30, 2013, Cubist announced that it had entered into a definitive merger agreement to acquire all outstanding shares of Optimer. Under the terms Optimer shareholders would receive $10.75 per share in cash upfront, and an additional $5 per share contingent on Optimer meeting certain sales milestones.

The investigation will determine whether Optimer's board of directors breached their fiduciary duties to stockholders by failing to satisfactorily shop the company before entering into this agreement. Our investigation will determine whether Cubist Pharmaceuticals, Inc. is underpaying for Optimer shares. In particular, most analysts target price for the stock is much higher than the buyout price.

If you are an Optimer shareholder and are interested in learning more about the investigation or your legal rights and remedies, please contact lead analyst Jim Baker (jimb@johnsonandweaver.com) at 619-230-0063.

Johnson & Weaver, LLP is a nationally recognized shareholders' rights law firm. The firm represents individual and institutional investors in shareholder derivative and securities class action lawsuits. For more information about the firm and its attorneys, please visit http://www.johnsonandweaver.com.

Johnson & Weaver, LLP
Jim Baker, 619-230-0063 Ext. 118
jimb@johnsonandweaver.com