RXi Pharmaceuticals Corporation (OTC: RXII), a biotechnology company focused on discovering, developing and commercializing innovative therapies addressing major unmet medical needs using RNA-targeted technologies, today announced the pharmacokinetic results of their single dose Phase 1 study with RXI-109 in healthy subjects. This drug candidate is a highly selective CTGF targeting sd-rxRNA® compound that is administered through intradermal injections to prevent or reduce dermal scarring following surgery or trauma, as well as for the management of hypertrophic scars and keloids.
In this study, 15 volunteers divided over 5 cohorts received single intradermal injections in a dose escalating manner, and blood was drawn at various time points to evaluate the distribution of the drug beyond the injected tissue, into the systemic circulation. Previous primate toxicology work with RXI-109 had shown that the peak blood levels obtained after intradermal injections with 10 mg/kg were approximately 3.5% of the peak levels obtained after intravenous injections with the same dose. With the different doses in the primate study, the dermal and systemic side effects in the animals were minimal. The maximum dose administered intradermally in the human subjects was on average only 0.3 mg/kg at the highest dose, i.e., more than 30 times lower than the dose given to the primates. The calculated relative systemic exposure in the 15 volunteers was between 1 and 7% (mean 5%), which is very similar to the systemic exposure in primates. As reported earlier, the drug was very well tolerated in all volunteers tested.
"These data confirm our first clinical observations, that subjects had no significant side effects or complaints after intradermal injection with RXI-109," said Dr. Geert Cauwenbergh, President and CEO of RXi Pharmaceuticals. He added that, "Considering the absence of toxicity in our primate toxicology studies at much higher doses, given both intradermally and intravenously, and considering the very similar low degree of systemic exposure we have found in our volunteers, we are confident in moving forward into a multiple dose Phase 1 study in the very near future. The subjects from our first study with RXI-109 are currently in the process of undergoing their abdominoplasty, which will provide samples that will allow us to also make a clinical and histological evaluation of single dose RXI-109 treatment versus placebo in these subjects."