Rib-X Pharmaceuticals is a New Haven, CT-based small molecule drug discovery and development company focused on the structure-based design of novel classes of anti-infective agents. Our technology platform is based on the high resolution crystal structure of the 50S subunit of the ribosome obtained by Thomas Steitz, Peter Moore and their co-workers. Since the publication of their early research (Science 289:905-929), Rib-X scientists have advanced the work to the analysis of the structures of many antibiotics complexed with the 50S. The structural data from these ligand binding studies are being used at Rib-X to prime parallel lead optimization programs focused on evaluating new chemistry ideas about antibiotic interactions with the multiple binding domains or drug targets within the 50S subunit. To interpret the chemistry of ligand binding, Rib-X has built on proprietary computational chemistry tools, packaged together in the software suite called Analog™, and initially provided by another scientific founder, Yale professor William Jorgensen. Analog™ permits Rib-X to couple chemical synthesis, biochemistry and crystallographic analysis in a structure-based drug design cycle resulting in the discovery of new compounds useful as anti-infective agents.

Rib-X technology offers a competitive advantage because many classical antibiotics work by inhibiting the function of the ribosome. Pfizer's $1.4b a year block buster antibiotic, Zithromax, is a well known example. Until the completion of the research endeavor of Steitz and Moore, the modes of action of these antibiotics had not been understood in chemical terms. During the first two years, Rib-X's research goal is to use the 50S subunit structural data to design a proprietary class of antibacterial agent that has broad-spectrum activity against antibiotic-resistant microorganisms. The medical need, the increase in antibiotic resistance and the difficulty in identifying new antibiotics is well documented in both the popular and scientific press. The current marketplace and low representation of new classes of antibiotics in clinical trials underscores the continuing value of identifying new agents.