Ketek

Drug Overview

Ketek (telithromycin; Sanofi) is an oral semisynthetic antibacterial agent of the ketolide class. The drug, which is the first ketolide to gain regulatory approval for the treatment of community-acquired pneumonia, is structurally related to the macrolide class of antibiotics. It exerts its antibacterial activity by blocking bacterial protein synthesis through binding to the 50S ribosomal subunit. Ketek is able to dually bind to domains II and V on the 23S part of the 50S ribosomal subunit. Ketek’s antibacterial spectrum includes a number of pathogens with clinical significance in respiratory infections, including aerobic Gram-positive organisms such as Streptococcus pneumonia, and Staphylococcus aureus (methicillin-sensitive strains).

Analyst Outlook

Ketek (telithromycin; Sanofi) is the first-to-market of the ketolide class of antibacterial agents. The drug’s enhanced mechanism of action allows it to retain activity against bacterial strains resistant to its structurally related macrolide antibiotics, as well as other older classes of antibacterial agents. Ketek’s activity against some bacterial pathogens with clinical significance in respiratory infections, such as community-acquired pneumonia (CAP), further enhanced its potential appeal in this market. However, the use of Ketek has been associated with multiple safety concerns that have limited its use in certain patient groups such as those with myasthenia gravis, as well as patients with a prior history of jaundice or hepatitis. These factors limited the drug’s overall clinical attractiveness, subsequently limiting its share of the CAP market. Datamonitor Healthcare anticipates that, as new antimicrobial agents with similar efficacy and better safety profiles launch, Ketek’s safety issues will continue to restrict its clinical attractiveness in the CAP market.