Tetraphase Pharmaceuticals, Inc. (Nasdaq:TTPH) Doses the First Patient in IGNITE4,Phase 3 Clinical Trial

Top-line IGNITE4 Data Expected in 4Q 2017

Results to Support NDA Filing for IV Eravacycline in cIAI

WATERTOWN, Mass., Oct. 14, 2016 (GLOBE NEWSWIRE) —  Tetraphase Pharmaceuticals, Inc. (NASDAQ:TTPH) today announced dosing of the first patient in IGNITE4, the Company’s phase 3 clinical trial evaluating the efficacy and safety of intravenous (IV) eravacycline compared to meropenem in complicated intra-abdominal infections (cIAI).  Eravacycline is a novel antibiotic candidate with potent activity against multidrug-resistant (MDR) pathogens, including carbapenem-resistant enterobacteriaceae (CRE), Acinetobacter baumannii, and colistin-resistant bacteria carrying the mcr-1 gene, that is being developed for the treatment of serious and life-threatening bacterial infections.

“Patient dosing is now underway in IGNITE4, and we continue to expect top-line data in the fourth quarter of 2017. If successful, these data, along with data from our positive IGNITE1 study in cIAI, will support a new drug application (NDA) submission for IV eravacycline in cIAI,” said Guy Macdonald, President and Chief Executive Officer of Tetraphase.  “Antibiotic resistance continues to be a growing public health threat and this critical issue is achieving attention on a global scale, most recently as an area of focus at the United Nations General Assembly.  Tetraphase is committed to being part of the solution by working to develop new antibiotics to treat these serious infections.”

IGNITE4 is a phase 3 randomized, double-blind, double-dummy, multicenter, prospective study that is designed to assess the efficacy, safety and pharmacokinetics of twice-daily eravacycline (1.0 mg/kg every 12 hours) compared with meropenem (1g every 8 hours) for the treatment of cIAI.  The study is expected to enroll approximately 450 adult patients at 75 centers worldwide.  The primary endpoint of IGNITE4 is clinical response at the test-of-cure (TOC) visit, which occurs 25 to 31 days after the initial dose of the study drug.  The primary efficacy analysis will be conducted using a 12.5% non-inferiority margin in the microbiological intent-to-treat (micro-ITT) population.  

About Eravacycline
Eravacycline is a novel, fully-synthetic tetracycline antibiotic being developed for the treatment of serious infections, including those caused by multidrug-resistant (MDR) pathogens that have been highlighted as urgent public health threats by both the World Health Organization and the U.S. Centers for Disease Control (CDC).  Eravacycline is Tetraphase’s lead product candidate in phase 3 clinical development for the treatment of complicated intra-abdominal infections (cIAI) and complicated urinary tract infections (cUTI).

Eravacycline is currently being investigated in the Company’s phase 3 IGNITE (Investigating Gram-negative Infections Treated with Eravacycline) program.  To date, eravacycline has been tested in over 1,300 patients and has been tested in two completed phase 3 trials – IGNITE1 in patients with cIAI and IGNITE2 in patients with cUTI.  In IGNITE1, twice-daily IV eravacycline met the primary endpoint by demonstrating statistical non-inferiority inferiority of clinical response compared to ertapenem, was well tolerated, and achieved high cure rates in patients with Gram-negative pathogens, including resistant isolates.  Tetraphase is currently evaluating eravacycline in a second phase 3 clinical trial in patients with cIAI (IGNITE4) comparing twice-daily IV eravacycline to meropenem.  Assuming a positive outcome in IGNITE4, the Company plans to use the results from IGNITE1 and IGNITE4 to support an NDA submission for IV eravacycline for the treatment of patients with cIAI.  The Company plans to initiate IGNITE3, an additional phase 3 trial evaluating once-daily IV eravacycline in patients with complicated cUTI.  Assuming a positive outcome, the Company plans to use the results from IGNITE3 to support a supplemental NDA (sNDA) submission for eravacycline in cUTI.  In parallel, Tetraphase is continuing its efforts to develop an oral dose formulation of eravacycline. A phase 1 clinical program is ongoing which is designed to evaluate and optimize the oral dosing regimen for eravacycline.

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 early or interim 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; whether the results of the Company’s trials will warrant regulatory submission and regulatory 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-Q, filed with the Securities and Exchange Commission on August 4, 2016. In addition, the forward-looking statements included in this press release represent our views as of October 14, 2016. 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.