Iclaprim, a Novel Diaminopyrimidine for the Treatment of Resistant Gram-Positive Infections

OBJECTIVES: To review the pharmacology, microbiology, in vitro susceptibility, pharmacokinetics, clinical trial data, safety and tolerability of iclaprim, a novel dihydrofolate reductase (DHER) inhibitor. DATA SOURCES: A MEDLINE search was conducted from 1966 through December 2008. Additional sources included abstracts from meetings of the Interscience Conference on Antimicrobial Agents and Chemotherapy and the Infectious Diseases Society of America from 2001 to 2008 and information available from the manufacturer's Website. STUDY SELECTION AND DATA EXTRACTION: In vitro and clinical studies, in addition to Phase 1, 2, and 3 clinical trials, were included. DATA SYNTHESIS: Iclaprim, a novel diaminopyrimidine and DHFR antagonist, has a mechanism of action similar to that of trimethoprim. It has in vitro activity mainly against gram-positive organisms, including resistant Staphylococcus aureus. In Phase 2 and 3 clinical trials, oral and intravenous administration of iclaprim was effective and well tolerated for the treatment of complicated skin and skin structure infections (cSSSI). Trials are currently ongoing for the treatment of ventilator-associated and healthcare-associated pneumonia. CONCLUSIONS: Iclaprim is a promising antimicrobial agent for the treatment of gram-positive organisms, including resistant S. aureus and trimethoprim-, macrolide-, fluoroquinolone-, and glycopeptide-resistant strains. Additionally, in vitro activity similar to that of trimethoprim has been observed against gram-negative and atypical organisms.