Tetraphase Pharmaceuticals Announces Positive Oral Dosing Data from Lead-in of IGNITE 2 Phase 3 Trial of Eravacycline in cUTI Support Advancement to Pivotal Portion

— Company on Track to Initiate Pivotal Portion of IGNITE 2 in Early 4Q '14 —

— Tetraphase to Host Conference Call and Webcast Today at 5:00 PM ET —

WATERTOWN, Mass.--(BUSINESS WIRE)-- Tetraphase Pharmaceuticals, Inc. (NASDAQ:TTPH) today announced that positive top-line results from the lead-in portion of its IGNITE 2 clinical trial, a two-part Phase 3 clinical trial studying the efficacy and safety of intravenous (IV) and oral formulations of eravacycline for the treatment of complicated urinary tract infections (cUTI), support advancement of the trial into its pivotal portion.

Data from the lead-in portion demonstrated that both IV-to-oral dosing regimens of eravacycline (1.5 mg/kg IV followed by 200 mg or 250 mg) compared favorably to levofloxicin. The responder outcome (the primary endpoint for the FDA) for the IV-to-oral 200 mg, IV-to-oral 250 mg and levofloxacin groups were 70.8%, 64.3% and 52.2%, respectively. The microbiological response (the primary endpoint for the European Medicines Agency) were 75.0%, 64.3% and 56.5%, respectively. The pharmacokinetics of both oral doses of eravacycline were comparable to the IV formulation. Overall, treatment was generally well tolerated in all three groups with the most common adverse events reported being nausea and emesis. Only two patients discontinued treatment as a result of drug related adverse events.

"We are very pleased with the results achieved in the lead-in portion of the trial, including the high percentage responder rate and pharmacokinetics of the oral formulation of eravacycline that were comparable to the IV formulation," said Guy Macdonald, President and CEO of Tetraphase. "We believe these results are a key step in demonstrating the efficacy and safety of eravacycline as an IV-to-oral treatment option in cUTI and its effectiveness against a broad spectrum of bacterial pathogens, including multidrug resistant Gram-negative bacteria. We look forward to sharing the results of the lead-in portion of IGNITE 2 with the FDA and confirming the dose to carry forward into the pivotal portion of the trial. We remain on track to initiate this stage of the trial in early 4Q '14."

Tetraphase plans to provide additional detail from the lead-in portion, and confirmation of the oral dose to be used in the pivotal portion, after sharing the data with the FDA, as previously agreed. Tetraphase plans to present the full data from the lead-in portion of the IGNITE 2 Phase 3 trial at an upcoming scientific meeting.

Conference Call Information

Tetraphase will host a conference call today at 5:00 pm Eastern Time to discuss the top-line data from the lead-in portion of the IGNITE 2 Phase 3 trial. The call can be accessed by dialing (844) 831-4023 (U.S. and Canada) or (731) 256-5215 (international). To access the live audio webcast, or the subsequent archived recording, visit the "Investors Relations — Events & Presentations" section of the Tetraphase website at www.tphase.com. The webcast will be recorded and available for replay on the Tetraphase website for 30 days following the call.

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 lead-in portion, in which approximately 120 patients, randomized 1:1:1, received eravacycline in one of two IV-to-oral switch dosing cohorts (1.5 mg/kg intravenously every 24 hours followed by 200 mg or 250 mg orally every 12 hours) or levofloxacin (750 mg intravenously every 24 hours followed by 750 mg orally every 24 hours). Tetraphase determined the two eravacycline oral dosing regimens based on its completed Phase 1 oral pharmacokinetic (PK) trial that indicated acceptable plasma drug levels and tolerability in healthy subjects at the 200 mg and 250 mg twice-daily dose levels.

Under the trial protocol, following treatment of approximately 120 patients in the lead-in portion of the trial, an evaluation of primary efficacy, safety and tolerability endpoints was to be conducted in a planned interim analysis to determine the dose regimen to be carried forward into the second portion of the trial. An additional 720 patients are expected to then be enrolled and randomized 1:1 to receive the selected dose regimen of eravacycline or levofloxacin. 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.

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. 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 our cash resources will be sufficient to fund our continuing operations into the first quarter of 2016; 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 September 2, 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.


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Source: Tetraphase Pharmaceuticals, Inc.