Tetraphase Pharmaceuticals is starting the summer flush with cash after a Series C financing round yielded $45 million. Excel Venture Management led the round.
We last checked in with Tetraphase in January, when the company was making the rounds at the JPMorgan Healthcare conference to tout its novel antibiotics platform. Tetraphase was spun out of the labs of Andrew G. Myers, chair of the chemistry department at Harvard University. Myers came up with a fully synthetic route to tetracycline derivatives that significantly expanded the diversity of the compounds. In the past, the semisynthetic routes to make tetracycline limited chemists to making tweaks to the C-7 and C-9 positions on the molecule.
Tetraphase’s technology, on the other hand, enables modifications at any position on the molecule. Indeed, their scientists have already made over 2,000 compounds, Joyce A. Sutcliffe, the company’s senior vice president of biology told me.
So what does diversity mean in terms of antibiotic activity? Sutcliffe provided the example of Paratek Pharmaceuticals’ PTK0796, a broad spectrum antibiotic that Novartis licensed in October in a deal worth up to $485 million. A modification at the C-9 position of tetracycline endowed PTK0796 with the ability to be given both intravenously and orally—desirable properties when you want to transition a patient from the hospital to home. “It just shows that even small changes make different properties in terms of pharmacokinetics, efficacy, and spectrum,” Sutcliffe said.
Now imagine being able to make tweaks at virtually any position on the molecule. Not only can they enable a drug to be taken orally and by IV, but can also improve the activity of the antibiotic. For example, some modifications have proven important to getting around the tetracycline reflux mechanisms, basically the two major pathways bacteria have evolved to pump drugs out of the cell before they can work their magic.
Tetraphase will use its sudden influx of cash to push several drugs into Phase I and Phase II clinical trials. TP-434 is a broad spectrum IV antibiotic poised to start Phase II studies this year. Two IV/oral antibiotics, TP-2758 for urinary tract infections and TP-834 for community-acquired bacterial pneumonia, will also be advanced.
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