Celsion Announces Potent, Durable Preclinical Lung Expression Data for Its Novel TheraSilence RNA Program

Celsion Corporation CLSN, a fully-integrated oncology company focused on the development of a portfolio of innovative cancer treatments, including directed chemotherapies, immunotherapies and RNA- or DNA-based therapies for the treatment of cancer and other difficult-to-treat diseases, today reported data from a preclinical study confirming that the Company's TheraSilence™ technology platform can safely and effectively deliver RNA to the lungs in non-human primates. TheraSilence™ is designed to enable the delivery of synthetically-generated mRNA, inhibitory RNA (RNAi) such as small inhibitory RNAs (siRNAs), microRNAs, microRNA mimics, and related molecules that can regulate protein expression at the transcript level by exploiting endogenous cell mechanisms. "The findings from this study are consistent with the data observed in earlier preclinical studies and underscore the differentiating and widespread potential of our TheraSilence™ RNA delivery platform," stated Dr. Khursheed Anwer, Celsion's Executive Vice President and Chief Scientific Officer. "Development for RNA therapeutics has been significantly limited due to the delivery challenges associated with nucleic acid-based therapies, with development efforts in the space focused primarily on diseases of the liver. Our chemically-flexible approach offers the opportunity to significantly expand the development of RNA therapies to include major unmet medical needs affecting the lung, such as lung cancer, asthma and pulmonary hypertension." The study was designed to evaluate the expression profile and safety of RNA formulated with Celsion's TheraSilence™ delivery system in non-human primates. Three primates were dosed in the study, receiving either TheraSilence-formulated RNA intravenously at one of two doses, or intravenous RNA formulated with a liver-directed formulation used as a positive control. Following the treatment, an analysis for safety and RNA expression was performed. In the study, TheraSilence-formulated signaling RNA resulted in preferential expression in the lungs, with expression in the liver at less than 15% of expression levels observed in the lungs. Expression levels in tissues other than the lung, spleen and liver were very low or at background levels. The TheraSilence-formulated RNA was well-tolerated at both dose levels as determined by safety analysis including complete blood cell count, blood chemistry, histopathology, interferon response and compliment activation. A liver-directed delivery system, used as a positive control for the study, yielded preferential expression in liver and spleen, with only background expression levels observed in the lung. These data build on previous preclinical studies indicating the preferential delivery of RNA to the lung using the TheraSilence™ RNA delivery system. A murine study evidenced that the delivery of TheraSilence-formulated siRNA molecules targeting anti-vascular endothelial receptor 2 (VEGF2), a protein that is critical for the growth of new blood vessels in tumors, significantly inhibit lung tumor growth. Additionally, delivery of a TheraSilence-formulated anti-micro RNA molecule into rats with experimentally induced pulmonary arterial hypertension appeared to normalize vascular remodeling that occurs in the lung and help restore cardiac function that is compromised as a result of the disease. "The data highlights the great potential of our TheraSilence™ technology platform to provide unique treatment options for lung diseases that are not addressable by conventional drugs," said Michael H. Tardugno, the Company's Chairman, President and Chief Executive Officer. "TheraSilence™ has significant potential in a wide variety of indications, including those that fall outside our core focus of oncology. Our strategy is to seek to maximize the value of this platform in the near-term by pursuing collaborations and licensing agreements, while focusing internal development efforts on our two clinical stage candidates, ThermoDox™ and GEN-1, our DNA-based immunotherapy for the localized treatment of ovarian and brain cancers."