Rib-X Pharmaceuticals has initiated Phase I trials of its first candidate for treating resistant infections. The candidate had been derived from the company's Rx-01 program, which utilizes X-ray crystallography and computational chemistry to facilitate drug design.
Rx-01 antibiotics are inhibitors of the ribosome, a complex cellular machine that catalyzes the chemical steps to produce proteins. The ribosome is composed of two complex subunits called the 30S and 50S ribosomal subunits. Many existing classes of antibiotics, including those used to treat both community- and hospital-acquired infections, are known to function by targeting the 50S. Among the classes of antibiotics that act this way are macrolides, ketolides and the oxazolidinones.