Enanta develops new ketolide class

Enanta Pharmaceuticals has discovered a type of macrolide that could represent a new class of antibiotic for the treatment of upper and lower respiratory tract infections.

The company has developed an extensive library of macrolides, which are one of the oldest classes of antibiotics with the first member of the class, erythromycin, having been introduced 50 years ago. This class has found extensive use in the treatment of RTIs, particularly after the introduction of second-generation macrolides such as clarithromycin and azithromycin.

Latterly, macrolides have become increasingly prone to resistance and offer weak activity against certain problem community-acquired pathogens. One macrolide variant aiming to overcome these limitations is the ketolide class, pioneered by Aventis with its recently launched Ketek (telithromycin) product.

Enanta claims to have developed a new class of bridged ketolides which offer activity against resistant pathogens as well as improved pharmacokinetic properties, including once-daily administration, lower dosages and a reduced potential for side effects.

The company presented the new class at the 4th International Symposium on Antimicrobial Agents and Resistance (ISAAR 2003) in Seoul, Korea.