SCIENTIFIC DISCUSSION
1 Introduction
The need for new antibacterial agents is greater than ever because of the emergence of multidrug resistance in common pathogens and the rapid emergence of new infections. Bacterial resistance is associated with treatment failures, increased mortality, and increased costs. Methicillin-resistant S. aureus (MRSA), glycopeptide-intermediate S. aureus (GISA) and glycopeptide-resistant enterococci (VRE or GRE) are of particular concern. In addition, resistance of gram-negative bacteria to all approved antimicrobials is emerging. Despite the need for new antimicrobial agents, the development of these agents is declining.
Tigecycline, a member of the glycylcycline class of antimicrobial agents, carries a glycylamido moiety attached to the 9-position of minocycline. As a bacteriostatic agent, it inhibits the growth of multiple resistant gram-positive, gram-negative, anaerobic, and atypical bacteria, including methicillin-resistant Staphylococcus aureus and extended-spectrum β-lactamase producers. Tigecycline remains vulnerable to the chromosomally-encoded multidrug efflux pumps of Proteeae and Pseudomonas aeruginosa. Consequently, tigecycline does not demonstrate significant in vitro activity against Pseudomonas aeruginosa and demonstrates only moderate in vitro activity against microorganisms belonging to Proteeae (Proteus spp., Providencia spp.and Morganella morganii). Due to the mechanism of action, the antibacterial activity of tigecycline is not expected to be affected by mechanisms that confer specific resistance to beta-lactam drugs, glycopeptides, quinupristin/dalfopristin, linezolid or other agents potentially useful against Gram-positive and Gram- negative bacterial species.
The claimed indications were Complicated skin and skin structure infections, including those with methicillin-resistant Staphylococcus aureus (MRSA)