Tetraphase spikes on a Phase III success for lead antibiotic

Tetraphase CEO Guy Macdonald

Shares of Tetraphase Pharmaceuticals ($TTPH) spiked 15% Wednesday afternoon after the biotech said its lead antibiotic hit its primary endpoint in a head-to-head Phase III study, leaving the company on track to file for an approval before the end of next year.

Researchers concluded that eravacycline fell within FDA and EMA guidelines for noninferiority status with ertapenem (Merck's Invanz) when used to combat a complicated intra-abdominal infection (cIAI). The final numbers, though, are being held back for a later scientific conference.

Tetraphase has been specializing on resistant gram-negative bacteria. The most common gram-negative pathogens in the study included Escherichia coli, Klebsiella pneumoniae, Pseudomonas and Bacteroides. More than 500 patients were recruited for this study, with eravacycline dosed 1.0 mg/kg every 12 hours, compared with ertapenem, dosed intravenously 1 g every 24 hours. The FDA's margin for noninferiority is 10% while the EMA allows 12.5%.

A regulatory success for Tetraphase would mark a significant advance for a small group of biotechs which is trying to push ahead with new antibiotics in the face of growing problems with drug-resistant bacterial infections. Big Pharma had largely bowed out of the field years ago, unhappy with the slim margins that have been available. But both Roche ($RHHBY) and Merck ($MRK)--which recently announced a $9.5 billion deal to buy back into the field with its acquisition of Cubist--have been attracted by the potential for new antibiotics for acute care situations.

Tetraphase went public in 2013 and was named a Fierce 15 company in 2010.

"The positive results from IGNITE 1 underscore that treatment with eravacycline could help a significant number of cIAI patients achieve a clinical cure for their difficult-to-treat Gram-negative infections," said Tetraphase CEO Guy Macdonald in a statement. "The success of this trial is an important milestone for the eravacycline pivotal program. These results, along with those from our ongoing Phase 3 IGNITE 2 trial in complicated urinary tract infections (cUTI) which are expected in mid-2015, would form the basis of regulatory submissions seeking approval for eravacycline in both indications. We continue to target a New Drug Application submission to the FDA by the end of 2015."

- here's the release

Special Report: Tetraphase Pharmaceuticals - 2010 Fierce 15