Locilex® (pexiganan cream 0.8%) is a chemically synthesized, 22-amino acid peptide isolated from the skin of the African Clawed Frog. Unlike the majority of antibiotics that work by inhibiting the replication of bacteria (bacteriostatic mechanism of action), Locilex® kills microbial targets through disruption of bacterial cell membrane permeability (bactericidal mechanism of action). Although this ability to disrupt cell membrane permeability as a mechanism of action is not unique among other antimicrobial peptides, a distinguishing feature of Locilex®, is its ability to do so in a broad spectrum of gram-positive, gram-negative, aerobic, and anerobic bacteria, as well as fungi. In addition, recently completed microbiology studies highlight the sensitivity of resistant bacteria, including methicillin-resistant staphylococcus aureus (or MRSA), vancomycin-resistant enterococcus (or VRE), extended-spectrum beta-lactamases (or ESBL) and multi-drug resistant (or MDR) bacteria, to pexiganan, the active pharmaceutical ingredient in Locilex®.
Formulated as an odorless, white to off-white topical cream, Locilex® affects only the area to which it is locally applied. Unlike oral and intravenous antibiotics, as well some topical antibiotics, Locilex® does not absorb into the bloodstream, which is host to a number of different bacteria other than bacteria causing a localized skin infection. Topical application also allows for delivery of a higher concentration of antibiotic to the infected area relative to oral and intravenous antibiotics. As a result, we believe that Locilex® has a low likelihood of developing bacterial resistance, both because the higher antibiotic concentration more effectively kills the infection-causing bacteria before they develop resistance, and because other bacteria in the bloodstream are not exposed, and therefore not given the chance to generate resistance. In a number of publications since 2011, including a report issued as recently as April 2014, the World Health Organization has declared antibiotic resistance as a “major threat to public health.”
In summary, Dipexium believes the key differentiating features of Locilex® are: (i) it has not generated resistant bacteria systemically; (ii) it has not generated cross resistance with other antibiotics; (iii) it has demonstrated bactericidal activity against a broad spectrum of pathogens, including difficult to treat gram-negative, anaerobic, and resistant bacteria; (iv) it has not been systemically absorbed; and (v) it has not caused any significant safety issues in over 500 patients treated in prior clinical trials. These features lead us to believe that Locilex® has the potential to become an ideal front-line treatment option for patients with mild DFI, as well as other mild and moderate skin and skin structure infections.