Rib-X Raises Another $20M, Led by Warburg Pincus, to Develop Late Stage Antibiotics

1/11/11Follow @xconomy

New Haven, CT-based Rib-X Pharmaceuticals has rounded up another sizable investment to carry out its antibiotic R&D.

The company said today it has raised $20 million in a financing led by Warburg Pincus, the giant private equity firm. Rib-X didn’t say in its statement who else invested, or whether it represents debt or equity financing. The last we wrote about Rib-X was in June, after the company had pulled in $5.5 million in debt financing.

Rib-X pronounced (RYE-bex), founded in 2000, has raised a ton of financing in its history. The company had pulled together $158 million as of this time a year ago, when I spoke to founder and former CEO Susan Froshauer for a detailed update. At that time, she was hoping to move one of the company’s lead drug candidates, delafloxacin, into a study of 800 patients with antibiotic-resistant infections they picked up in the hospital. She was also looking for a Big Pharma partner.

The big partnership hasn’t come to fruition yet. Back in March, Froshauer was replaced as CEO by Mark Leuchtenberger. Rib-X, in today’s announcement, said it plans to take an interim step with a smaller Phase IIb study to “validate new objective endpoints” that will help it evaluate delafloxacin before the drug candidate goes into a bigger, pivotal clinical trial. The company also plans to run a long-term animal study with its other advanced drug candidate, radezolid, to see how it stacks up with competitors, and it plans to nominate another candidate against multi-drug resistant bacteria for clinical trials.

“We are grateful for the confidence and continued strong financial support of our investors and look forward to being able to deliver on the clinical promise of our pipeline,” Leuchtenberger said in today’s statement.

I’m planning to meet Leuchtenberger tomorrow at the JP Morgan Healthcare Conference and will plan to follow up with more later on what to expect from Rib-X in the year ahead.

By posting a comment, you agree to our terms and conditions.

  • http://www.xconomy.com/author/ghuang/ Gregory T. Huang

    This just in from Rib-X:

    “We’re happy that we have the support and commitment of our existing investors in this convertible debt financing that will allow Rib-X to substantially advance its core antibiotic assets.

    The current round was led by Warburg Pincus and included SR One, ABS Ventures, Radius Ventures, Axiom Venture Partners and Connecticut Innovations. To date, Rib-X has been able to raise a total of approximately $190 million through a mix of equity and debt financing.”