Sirna Therapeutics, Inc. has announced the first program to apply RNA interference (RNAi) technology to asthma, a highly prevalent, chronic disease accounting for an estimated $13 billion in healthcare costs in the United States, a number which is forecast to grow considerably by the end of the decade.
Sirna is targeting key Th2 cytokines that play a critical role in inflammation and bronchconstriction in the airways. Results of preclinical animal studies conducted in collaboration with the National Jewish Medical and Research Center using chemically modified, systemically delivered short interfering RNAs (siRNAs) showed statistically significant reduction of airway hyperresponsiveness (66%) in the RNAi treatment group. Following additional preclinical studies, the company anticipates initiating human trials in 2006.
Extensive experimental and clinical data has demonstrated a critical role for cytokines generated by Th2 lymphocytes in the pathogenesis of asthma. Certain key cytokines orchestrate airway inflammation which underlies airway hyperresponsiveness, while others regulate the production of immunoglobulin E (IgE) in allergic asthmatics. Knocking out these cytokines by systemic or local (aerosol) delivery to the respiratory tract would be of obvious benefit in treating the disease. Sirna is currently developing siRNAs formulated to provide a long duration of activity after local administration to the lungs.
Dr. Erwin Gelfand, Chairman, Department of Pediatrics, National Jewish Medical and Research Center, commented, "Pre-clinical research in the application of Sirna's short interfering RNAs in the treatment of asthma has demonstrated proof of feasibility in animal models that siRNAs may prove to be a very novel and effective therapy for treating asthma in humans. We are extremely excited to be working with Sirna Therapeutics in this collaborative research program and look forward to submitting our data to peer review in the near future. Our hope is that asthma patients will receive significant benefits from the application of an RNAi therapy to treat this very prevalent and chronic disease."