XF-73 (Exeporfinium chloride) is an experimental drug candidate. It is an anti-microbial that works via weakening bacteria cell walls. It is a potential treatment for methicillin-resistant Staphylococcus aureus (MRSA) and possibly Clostridium difficile. It is being developed by Destiny Pharma Ltd. Structurally, it is a dicationic porphyrin. It has completed a phase I clinical trial for nasal decolonisation of MRSA—being tested against 5 bacterial strains. It seems unlikely to cause MRSA to develop resistance to it. In 2014, a phase 1 clinical trial for nasal administration was run.