TTPH Tetraphase Pharmaceuticals Inc

Tetraphase Pharmaceuticals, Inc. (NASDAQ:TTPH), a clinical stage biopharmaceutical company developing novel antibiotics to treat life-threatening multidrug-resistant (MDR) infections, today announced that it has been selected for addition to the NASDAQ Biotechnology Index® (NASDAQ:^NBI). The annual re-ranking of the NASDAQ Biotechnology Index will become effective prior to U.S. market open on Monday, December 18, 2017.

The NASDAQ Biotechnology Index is designed to track the performance of a set of securities listed on The NASDAQ Stock Market® (NASDAQ®) that are classified as either biotechnology or pharmaceutical according to the Industry Classification Benchmark (ICB). The NASDAQ Biotechnology Index is calculated under a modified capitalization-weighted methodology and ranked on annual basis. All securities in the NASDAQ Biotechnology Index are listed on the NASDAQ Global Market or the NASDAQ Global Select Market, and meet minimum market value and share volume requirements among other criteria.

The NASDAQ Biotechnology Index is the basis for the iShares NASDAQ Biotechnology Index(SM) Fund. In addition, options based on the iShares NASDAQ Biotechnology Index Fund trade on various exchanges. For more information about the NASDAQ Biotechnology Index visit www.nasdaq.com.

About Tetraphase Pharmaceuticals, Inc.Tetraphase is a clinical-stage biopharmaceutical company using its proprietary chemistry technology to create novel antibiotics for serious and life-threatening bacterial infections, including those caused by many of the multidrug-resistant (MDR) bacteria highlighted as urgent public health threats by the CDC. Tetraphase has created more than 3,000 novel tetracycline analogs using its proprietary technology platform. Tetraphase's pipeline includes three antibiotic clinical candidates: eravacycline, which is in phase 3 clinical trials, and TP-271 and TP-6076, which are in phase 1 clinical trials. Please visit www.tphase.com for more company information. 

Investor Contacts:Argot PartnersMaeve Conneighton206-899-4940maeve@argotpartners.com

Media Contact:Sam Brown Inc.Mike Beyer312-961-2502Mikebeyer@sambrown.com