<unk>  (INN), codenamed AR-100 and RO-48-2622, is a diaminopyrimidine dihydrofolate reductase (DHFR)-inhibiting extended-spectrum antibiotic active against gram positive organisms being developed for the treatment of complicated skin and soft tissue infections caused by antibiotic-resistant bacteria. It is structurally related to trimethoprim. In Phase III clinical trials, intravenously-administered<unk>  was found to be as effective as and better tolerated than linezolid in people with skin and soft tissue infections, many caused by methicillin-resistant Staphylococcus aureus (MRSA). In vitro,<unk>  is highly active against MRSA, vancomycin-resistant Staphylococcus aureus (VRSA), strains of Streptococcus pneumoniae resistant to several common antibiotics, and some Gram-negative bacteria.
A new drug application for<unk>  was filed with the U.S. Food and Drug Administration in March 2008, and a marketing authorisation application (MAA) was accepted by the European Medicines Agency on August 21, 2008. Phase II clinical trials are being conducted to assess whether<unk>  can be taken by mouth as well as intravenously and whether it is effective for the treatment of hospital-acquired pneumonia.<unk>  was granted fast track status by the FDA, but approval of the drug was eventually declined in 2009 and no further development has taken place since then.
Iclaprim
Cefroxadine
Azatadine
Alcaftadine
Nalmefene
Nifurtimox
Desloratadine
Telithromycin