Tetraphase Pharmaceuticals Inc. ("Tetraphase") is an American company developing novel antibiotics to treat multi-drug resistant bacterial infections.

According to the law firm press release, the Complaint alleges that Tetraphase and certain insiders issued materially false and misleading statements to investors. In particular, it is alleged that throughout the class period, Tetraphase made positive statements about the efficacy and potential for its drug Eravacycline to achieve approval by the FDA, despite knowledge that a pivotal portion of its IGNITE2 phase 3 clinical trial for Eravacycline would fail to achieve its primary endpoint of statistical non-inferiority compared to the antibiotic Levofloxacin.

On September 8, 2015, the Company announced that the pivotal portion of its IGNITE2 phase 3 clinical trial of Eravacycline did not achieve its primary endpoint. Following this news, shares of Tetraphase fell from a close of $44.78 on September 8, 2015, to a close of $8.36 per share on September 10, 2015—a loss of more than 80% in market value.

On May 25, 2016, the Court issued an Order consolidating cases and appointing Lead Plaintiff and Counsel. Lead Plaintiffs filed an amended complaint on July 25. The Complaint was amended again on August 25.

On May 9, 2017, the Court issued an Order granting Defendants' Motion to Dismiss. This case was closed. On May 19, Lead Plaintiffs filed a Notice appealing the Court's Decision to dismiss the case. On December 11, the Court of Appeals ordered the appeal voluntarily dismissed at the request of the Lead Plaintiffs.