Rib-X Pharma, and Its Lead Antibiotic, Gear Up for Prime Time

Rib-X Pharmaceuticals is gearing up to reveal mid-stage clinical results for its lead antibiotic that could advance the heavily backed biotech firm to a point at which larger drug companies often want a piece of the action.

New Haven, CT-based Rib-X, which has raised $123 million in private capital since it was founded in 2001, plans to report on two Phase 2 trials of its antibiotic, radezolid, at the Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) in Washington, D.C., late this month. Radezolid, which was tested in separate studies as a treatment for types of pneumonia and skin infections, is a small molecule designed with Rib-X’s proprietary computational system that identifies points of vulnerability and sources of antibiotic resistance in infection-causing bacteria.

Rib-X CEO Susan Froshauer foresees a day when her company’s technology could offer physicians a variety of antibiotic options to accurately target different infections. “The platform ensures a sustainable franchise,” Froshauer says. “We can do this over and over again, and we have now validated that by getting our own molecule through Phase 2.”

Froshauer, a former executive in the strategic alliance group of drug giant Pfizer (NYSE:[[ticker:PFE]]), is very much in pitch mode when she talks about the progress of her small company. Though she prefers not to discuss specifics of the Phase 2 studies—the results of which are under wraps until the ICAAC meeting from October 25 to 28—she says the firm is in active discussions with potential partners. (Given her connections at Pfizer, which markets the antibiotic linezolid, I asked her whether she was in partnership talks with her former employer. She didn’t bite.)

Speaking of the Pfizer antibiotic, Froshauer describes her firm’s radezolid as a next-generation linezolid. Sold under the trade name Zyvox, linezolid is Pfizer’s lucrative answer to antibiotic-resistant bugs that cause forms of pneumonia and skin infections, generating revenue of $944 million in 2007, up 21 percent from the prior year, according to Pfizer. But bacteria learn quickly, and strains resistant even to linezolid have emerged over the past several years. Froshauer says that her lead antibiotic has shown an ability to fight such linezolid-resistant bugs, and the Phase 2 trials her firm is about to showcase put the two antibiotics head-to-head.

Radezolid isn’t the only clinical candidate in Rib-X’s pipeline.

Author: Ryan McBride

Ryan is an award-winning business journalist who contributes to our life sciences and technology coverage. He was previously a staff writer for Mass High Tech, a Boston business and technology newspaper, where he and his colleagues won a national business journalism award from the Society of American Business Editors and Writers in 2008. In recent years, he has made regular TV appearances on New England Cable News. Prior to MHT, Ryan covered the life sciences, technology, and energy sectors for Providence Business News. He graduated with honors from the University of Rhode Island in 2001 with a bachelor’s degree in communications. When he’s not chasing down news, Ryan enjoys mountain biking and skiing in his home state of Vermont.