Rib-X Antibiotic Passes Clinical Trial, Hopes to Snag Partner

Rib-X Pharmaceuticals, the New Haven, CT-based developer of novel antibiotics, is announcing today that one of its experimental treatments passed a mid-stage clinical trial for patients with a common form of pneumonia. It’s looking to deal with a Big Pharma company with the money and resources to take the drug through the next steps needed for FDA approval.

The study looked at 160 patients with mild to moderate community-acquired pneumonia, who were randomly assigned to get one of three different doses of Rib-X’s oral pill version of radezolid (pronounced ruh-DAY-zo-lid). Researchers found that 78 to 92 percent of patients were considered clinically cured, while the most common side effect was a mild irritation in the intestines.

The Rib-X antibiotic was designed with the help of a proprietary computer system that identified points of vulnerability in bacteria, and ways in which they develop resistance to existing drugs, as Ryan reported in October. The company’s goal is to create two versions of radezolid, an oral and intravenous form, so that physicians can use them to treat a wide-range of bacterial invaders, both among hospitalized patients and those who can take an oral pill at home. If Rib-X can navigate the final stage of clinical trials to prove both of these versions are effective, it will be in position to compete with one of Pfizer’s fast-growing products, linezolid (Zyvox), which generated $1.1 billion in sales last year.

“We feel this is very promising data,” says Susan Froshauer, Rib-X’s CEO. “We’re not seeing the kind of bone marrow suppression that you see with other treatments in the class.”

Still, the data is from a mid-stage study, so it’s too early to conclude that this drug will be a winner. The point was to assess the lowest possible dose at which Rib-X could see an anti-bacterial effect, Froshauer says. Researchers saw comparable effectiveness at all three doses tested,

Author: Luke Timmerman

Luke is an award-winning journalist specializing in life sciences. He has served as national biotechnology editor for Xconomy and national biotechnology reporter for Bloomberg News. Luke got started covering life sciences at The Seattle Times, where he was the lead reporter on an investigation of doctors who leaked confidential information about clinical trials to investors. The story won the Scripps Howard National Journalism Award and several other national prizes. Luke holds a bachelor’s degree in journalism from the University of Wisconsin-Madison, and during the 2005-2006 academic year, he was a Knight Science Journalism Fellow at MIT.