Recce Pharmaceuticals Ltd (ASX:RCE) (FSE:R9Q), a company developing new classes of synthetic anti-infectives, has demonstrated the positive efficacy of its broad-spectrum anti-infective RECCE® 327 (R327) against necrotizing fasciitis, also known as flesh-eating disease.
Necrotizing fasciitis, a life-threatening bacterial infection with a mortality rate of up to 80%, is associated with two main strains of bacteria Clostridium perfringens (C. perfringens) and Streptococcus pyogenes (S. pyogenes).
Notably, R327 has been shown to reduce deadly ‘flesh-eating’ bacterial count below limit of quantification (BLOQ) within 24 hours, at varying concentrations.
In addition, R327 BLOQ efficacy is as early as 30 minutes in C. perfringens a leading bacterial cause of myonecrosis also known as gas gangrene.
Evaluating in vitro bactericidal properties
The study was conducted by an independent contract research organisation to evaluate the in vitro bactericidal properties of R327 against C. perfringens and S. pyogenes.
Doses of R327 up to 4,800 parts per million (ppm) were tested, covering concentrations from 0.5x to 8x the minimum inhibitory concentration (MIC).
The strains tested were S. pyogenes - a susceptible strain; S. pyogenes - an erythromycin-resistant strain; and C. perfringens.
“Rapid efficacy”
Recce chief scientific officer Michele Diliza said: “While necrotizing fasciitis is a rare and extremely challenging disease for physicians to manage, it is highly traumatising for patients and their families, often leading to serious complications and even death.
“A broad-spectrum anti-infective with rapid efficacy has the potential to significantly change the treatment paradigm and save lives.
“We have been thoroughly impressed with the efficacy that R327 has demonstrated thus far, as it reinforces our belief in the potential of this compound against such aggressive, life-threatening bacteria.”
Bactericidal effects
The R327 concentrations and time points that yielded a bactericidal effect are as follows:
- At hours 6 and 24, R327 showed bactericidal activity against the S. pyogenes susceptible strain at 1,200 ppm, 2,400 ppm and 4,800 ppm, while also achieving a BLOQ at the 24-hour count with concentrations of 2,400 ppm and 4,800 ppm (4X – 8X MIC);
- In addition to the susceptible strain, R327 achieved bactericidal effect at concentrations 600, 1,200 ppm and 2,400 ppm (2X – 8X MIC), while achieving a BLOQ at 2,400 ppm (8X MIC) in 24-hour counts; and
- R327 further demonstrated bactericidal effect against C. perfringens at 500 ppm, 1,000 ppm, 2,000 ppm and 4,000 ppm (1X – 8X MIC) respectively, showing efficacy as early as 30 minutes, and a BLOQ at these concentrations in 24-hour counts.
Recce has achieved 99.9% (3-log) bacterial reduction in all bacteria tested, at various concentrations.
S. pyogenes is a species of gram-positive bacteria and can cause life-threatening infections such as scarlet fever, bacteremia (bacteria in the blood), pneumonia, necrotizing fasciitis, myonecrosis and streptococcal toxic shock syndrome.
Also, C. perfringens is a gram-positive pathogen that is a leading cause of myonecrosis and a species that thrives in nil/low oxygen environments, which can cause infections in diabetic wounds/ulcers – a common characteristic of bacterial anaerobes.