Tetraphase Pharmaceuticals Announces Initiation of Pivotal Portion of IGNITE 2 Phase 3 Trial of Eravacycline in cUTI

— Company Selects 200 mg Oral Dose for Pivotal Portion –

WATERTOWN, Mass.--()--Tetraphase Pharmaceuticals, Inc. (NASDAQ:TTPH) today announced initiation of patient enrollment in the pivotal portion of its IGNITE 2 Phase 3 clinical trial, a two-part trial studying the efficacy and safety of intravenous (IV) and oral formulations of eravacycline for the treatment of complicated urinary tract infections (cUTI). The company has selected the 200 mg eravacycline oral dose for the pivotal portion of the study after evaluating the positive results from the lead-in portion of the trial.

As previously reported, in the lead-in portion of the trial, the IV-to-oral dosing regimen of eravacycline (1.5 mg/kg IV followed by 200 mg oral dose) compared favorably to levofloxacin, the comparator drug in the trial. The responder outcomes (FDA endpoint) for the IV-to-oral 200 mg and levofloxacin groups were 70.8% and 52.2%, respectively. The microbiological responses (EMA endpoint) were 75.0% and 56.5%, respectively. Overall, treatment was generally well tolerated in all groups, and the pharmacokinetics of the IV-to-oral 200 mg dose of eravacycline were comparable to the IV formulation. Tetraphase plans to present the full data from the lead-in portion of the IGNITE 2 Phase 3 trial at an upcoming scientific meeting.

"Initiation of the pivotal portion of the IGNITE 2 trial is an important milestone and we look forward to top-line data from the study in mid-2015," said Guy Macdonald, President and CEO of Tetraphase. "We believe eravacycline is a differentiated antibiotic candidate given its potential as an IV-to-oral transition therapy and its activity against a wide variety of bacterial pathogens, including multidrug-resistant Gram-negative bacteria. IGNITE 2 is the second study in our IGNITE pivotal program, which also includes IGNITE 1, a Phase 3 clinical trial of an IV formulation of eravacycline in complicated intra-abdominal infections. We expect to announce top-line data from IGNITE 1 early in the first quarter of 2015.”

About IGNITE 2

IGNITE 2 is a two-part, randomized, multi-center, double-blind, Phase 3 clinical trial designed to assess the efficacy and safety of eravacycline compared with levofloxacin in the treatment of cUTI at approximately 150 clinical trial sites worldwide. The two-part trial features a recently completed lead-in portion which was designed to determine the dose regimen to be carried forward into the pivotal portion of the trial. For the pivotal portion, an additional 720 patients are expected to be enrolled and randomized 1:1 to receive eravacycline or levofloxacin (1.5 mg/kg intravenously every 24 hours followed by 200 mg orally every 12 hours) or levofloxacin (750 mg intravenously every 24 hours followed by 750 mg orally every 24 hours). This 720-patient portion of the trial is designed to be a non-inferiority (10% margin) study. The primary endpoint for the FDA is the responder outcome (a combination of clinical cure rate and microbiological response) in the Microbiological Intent-to-Treat (micro-ITT) Population at the Post-Treatment visit (defined as 6-8 days after the completion of therapy). For the EMA, the primary endpoint is the microbiological response in the micro-MITT and microbiologically evaluable populations at the Post Treatment visit. Top-line results from the pivotal portion of the study are expected to be available in mid-2015.

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 multidrug-resistant (MDR) bacterial infections, including those caused by many of the MDR Gram-negative bacteria highlighted as urgent public health threats by the Centers for Disease Control and Prevention (CDC). Tetraphase's lead product candidate, eravacycline, is being developed as a broad-spectrum intravenous and oral antibiotic in the IGNITE program (Investigating Gram-negative Infections Treated with Eravacycline). Under this program, two Phase 3 clinical trials are ongoing: IGNITE 1 for the indication of complicated intra-abdominal infections (cIAI) and IGNITE 2 for complicated urinary tract infections (cUTI). Tetraphase has created more than 3,000 novel tetracycline analogs using its proprietary technology platform; in addition to eravacycline, Tetraphase has generated multiple preclinical antibiotic candidates that are currently being evaluated for clinical suitability.

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 our cash resources will be sufficient to fund our continuing operations for the period we anticipate; whether the top line results from the lead in portion of the trial will be predictive of the final results of the trial; whether results obtained in preclinical studies and early clinical trials will be indicative of results obtained in future clinical trials; whether eravacycline will advance through the clinical trial process on a timely basis or at all; whether enrollment for clinical trials will be achieved in the time frame expected; whether submissions will be made and approvals will be received from the United States Food and Drug Administration or equivalent foreign regulatory agencies on a timely basis or at all; whether, if eravacycline obtains approval, it will be successfully distributed and marketed; and other factors discussed in the "Risk Factors" section of our most recent Quarterly Report on Form 10-Q, filed with the Securities and Exchange Commission on August 12, 2014. In addition, the forward-looking statements included in this press release represent our views as of October 6, 2014. 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.

Contacts

Investor:
Tetraphase
Teri Dahlman, 617-600-7040
tdahlman@tphase.com
or
Argot Partners
Susan Kim, 212-600-1902
susan@argotpartners.com
or
Media:
Sam Brown Inc.
Mike Beyer, 773-463-4211
beyer@sambrown.com

Contacts

Investor:
Tetraphase
Teri Dahlman, 617-600-7040
tdahlman@tphase.com
or
Argot Partners
Susan Kim, 212-600-1902
susan@argotpartners.com
or
Media:
Sam Brown Inc.
Mike Beyer, 773-463-4211
beyer@sambrown.com