Rib-X raises $20M to support development of broad spectrum antibiotics pipeline

Rib-X Pharmaceuticals, Inc. today announced that the Company has raised $20 million to support ongoing development of the Company's industry-leading broad spectrum antibiotics pipeline, including late-stage clinical development of delafloxacin, which is expected to enter a Phase 2b study in early 2011.

“We are pleased to continue to support the Rib-X management team and the Company's innovative antibiotic pipeline, which targets infections resistant to existing antibiotics”

"2011 will be a transformational year for Rib-X and these funds will directly support a number of key initiatives for the Company," said Mark Leuchtenberger, President and Chief Executive Officer at Rib-X. "In early 2011, we will begin a Phase 2b delafloxacin study to validate new objective endpoints for a near-term Phase 3 study and will initiate a long-term preclinical safety study with radezolid to demonstrate its key points of differentiation. We also expect to nominate an initial development candidate with activity against multi-drug resistant Gram-negative bacteria from our Rχ-04 program in early 2011. 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."

The financing was led by current investor Warburg Pincus LLC. "We are pleased to continue to support the Rib-X management team and the Company's innovative antibiotic pipeline, which targets infections resistant to existing antibiotics," said Jonathan Leff, Managing Director at Warburg Pincus. "Through its deep expertise in antibiotics and insights in structure-based drug design around the bacterial ribosome, Rib-X has brought two differentiated products into advanced clinical development and has created a novel antibiotic discovery platform with the capability to target even the most resistant Gram-negative infections."

The Company's pipeline includes:

• Delafloxacin, an empiric first line, hospital focused novel fluoroquinolone antibiotic that offers both IV and oral versatility in the treatment of resistant infections;
• Radezolid, a next generation oxazolidinone antibiotic designed to be safer, have a broader spectrum of coverage and increased activity against Gram-positive organisms as compared to other oxazolidinones; and
• Rχ-04, the broadest spectrum novel class of antibiotics active against serious, rapidly emerging multi-drug resistant bacteria, including Gram-negative bacteria.