OPT-80, a macrocyclic antimicrobial agent for the treatment of Clostridium difficile infections: a review

Clostridium difficile-associated diarrhoea has become a major problem over the last years. Increasing incidence and more severe clinical cases initiated the search for new treatment options.

OPT-80, also known as tiacumicin B, lipiarmycin or PAR-101, is a macrocyclic antimicrobial with little or no systemic absorption after oral administration and narrow activity spectrum against Gram-positive aerobic and anaerobic bacteria.

Data on OPT-80 available from published studies, presentations at conferences and the manufacturer were collected and reviewed.

The in vitro studies of OPT-80 and clinical C. difficile strains showed high activity at low concentrations. Safety and efficacy of the drug were found to be favourable. More Phase II and III clinical trials are to be completed.