Tetraphase Pharmaceuticals to Present Data at 27th

WATERTOWN, Mass., April 21, 2017 (GLOBE NEWSWIRE) -- Tetraphase Pharmaceuticals, Inc. (NASDAQ: TTPH ), a clinical stage biopharmaceutical company developing novel antibiotics to treat life-threatening multidrug-resistant (MDR) infections, today announced seven data presentations at the 27 ^th European Congress of Clinical Microbiology and Infectious Diseases (ECCMID), taking place April 22-25 in Vienna, Austria. Presentations will include information about the company’s lead drug candidate, eravacycline, as well as data from its TP-6076 program.

“The data we are presenting at ECCMID this year continue to demonstrate the potent activity of eravacycline against a wide range of bacteria, including multidrug-resistant pathogens that cause some of the most serious and life-threatening infections,” said Guy Macdonald, President and Chief Executive Officer of Tetraphase Pharmaceuticals. “Eravacycline data show potent activity against many of the organisms identified by the World Health Organization and the U.S. Centers for Disease Control to pose urgent or serious threats to human health, specifically Gram-negative bacteria Acinetobacter baumannii and Enterobacteriaceae , including carbapenem-resistant or extended beta-lactamase producing phenotypes, as well as Gram-positive bacteria Staphylococcus aureus and enterococci, including methicillin- or vancomycin-resistant phenotypes.”

Mr. Macdonald continued, “We are also very excited about the emerging profile of our earlier stage compound, TP-6076. Data presentations at ECCMID highlight its potency against multidrug-resistant Acinetobacter baumannii and carbapenem-resistant Enterobacteriaceae, demonstrated in clinical isolates that were pan-resistant to multiple antibiotic classes.”

The details for the data presentations at ECCMID are as follows:

Eravacycline presentations:

Poster Title:   In vitro activity of eravacycline and comparators against Staphylococcus aureus and enterococci, including methicillin-resistant and vancomycin-resistant subgroups, collected from European hospitals in 2015 Date and time: Monday, April 24 from 12:30 – 1:30 p.m. CEST Location: Poster Area Poster number: #P1358 Session info: Drugs against Gram-positives – more data; Paper poster session

Poster Title: In vitro activity of eravacycline and comparators against Acinetobacter baumannii, Stenotrophomonas maltophilia and Enterobacteriaceae , including carbapenem-resistant and ESBL phenotype subgroups, collected from European hospitals in 2015 Date and time: Monday, April 24 from 12:30 – 1:30 p.m. CEST Location: Poster Area Poster number: #P1260 Session info: New data on new tetracyclines; Paper poster session

Poster title:   Comparative in vitro activity of eravacycline, a novel fluorocycline, against mcr-1 -positive Escherichia coli & Klebsiella pneumoniae Date and time: Monday, April 24 from 12:30 – 1:30 p.m. CEST Location: Poster Area Poster number: #P1258 Session info: New data on new tetracyclines; Paper poster session

Poster title:   Eravacycline, a novel fluorocycline, has antibacterial activity against carbapenem-resistant Enterobacteriaceae (CRE) & Acinetobacter spp. (CRA) Date and time: Monday, April 24 from 12:30 – 1:30 p.m. CEST Location: Poster Area Poster number: #P1259 Session info: New data on new tetracyclines; Paper poster session

Poster title:  Antibacterial activity of eravacycline, a novel fluorocycline, compared to established antimicrobials, against contemporary clinical isolates from Tanta, Egypt. Date and time: Monday, April 24 from 12:30-1:30 p.m. CEST Location: Poster Area Poster number:   #P1261 Session info: New data on new tetracyclines; Paper poster session

TP-6076 presentations:

Poster title:   In-vitro activity of the novel fluorocycline TP-6076 against carbapenem non-susceptible Acinetobacter baumannii Date and time: Monday, April 24 from 12:30-1:30 p.m. CEST Location: Poster Area Poster number:   #P1364 Session info: New discoveries against Gram-negatives; Paper poster session

Poster title:  TP-6076 is active against Carbapenem- and Polymyxin-resistant Enterobacteriaceae and Acinetobacter baumannii isolates in the FDA-CDC Antimicrobial Resistance Isolate Bank Panels. Date and time: Monday, April 24 from 12:30-1:30 p.m. CEST Location: Poster Area Poster number:   #P1365 Session info: New discoveries against Gram-negatives; Paper poster session

Full abstracts can be found on the ECCMID website at http://www.eccmid.org/ .

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.

Forward-Looking Statements Any statements in this press release about our future expectations, plans and prospects, including statements regarding our strategy, future operations, prospects, plans and objectives, and other statements containing the words "anticipates," "believes," "expects," "plans," "will" and similar expressions, constitute forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995. Actual results may differ materially from those indicated by such forward-looking statements as a result of various important factors, including: whether results obtained in previous clinical trials will be indicative of results obtained in future clinical trials; whether eravacycline or any other clinical candidate will advance through the clinical trial process on a timely basis or at all; whether the results of the Company's development efforts will warrant regulatory submission and whether any such submissions will receive approval from the United States Food and Drug Administration or equivalent foreign regulatory agencies; whether, if any clinical candidate obtains approval, it will be successfully distributed and marketed; and other factors discussed in the "Risk Factors" section of our quarterly report on Form 10-K, filed with the Securities and Exchange Commission on March 13, 2017. In addition, the forward-looking statements included in this press release represent our views as of April 21, 2017. We anticipate that subsequent events and developments will cause our views to change. However, while we may elect to update these forward-looking statements at some point in the future, we specifically disclaim any obligation to do so.

Investor Contacts: Tetraphase Pharmaceuticals Teri Dahlman 617-600-7040 tdahlman@tphase.com Argot Partners Maeve Conneighton 206-899-4940 maeve@argotpartners.com Media Contact: Sam Brown Inc. Mike Beyer 312-961-2502 mikebeyer@sambrown.com