A new concept

By addressing the issue of resistance, the XF series represents an entirely different approach to the prophylaxis and treatment of infectious disease:

• Structurally distinct from all existing therapies – dicationic porphyrins
• Mechanism of action is fundamentally different from all antibiotics
• Potentially offering major advantages in controlling drug-resistant bacteria
• Highly potent against a broad spectrum of Gram-positive bacteria
• Bactericidal against methicillin-resistant Staphylococcus aureus (MRSA)
• Likelihood of resistance developing is very remote

Unlike antibiotics which use specific surface receptors, XF compounds adhere to bacteria via electrostatic binding.

Potent antibacterial action

XF compounds have in vitro bactericidal activity against a wide range of bacteria at lower concentrations than traditional antibiotics. They have been shown to be effective at killing a wide range of Gram-positive aerobic bacteria such as Staphylococcus spp. (multiple strains of methicillin-resistant Staphylococcus aureus (MRSA), methicillin-susceptible Staphylococcus aureus, Staphylococcus epidermidis), Streptococcus spp, Corynebacterium spp. and Enterococcus spp. They are also active against Gram-positive anaerobic bacteria such as Clostridium difficile and Propionibacterium acnes, and against Gram-negative aerobic and anaerobic bacteria.

Likelihood of resistance is very remote

While the mechanism of action has yet to be fully elucidated, the XF series clearly acts in a fundamentally different way compared with antibiotics and is therefore not predisposed to any of the current pathways by which drug resistance has developed. Indeed, in studies of XF-73 in MRSA, in contrast with traditional antibiotics, no resistance has emerged, even after 50 repeat passages!