Rosetta Genomics Reports In-Vivo Efficacy Data for a Systemic MicroRNA Therapeutic for Liver Cancer
News Feb 16, 2009
Rosetta Genomics Ltd. reported the first ever in-vivo efficacy data for a systemic microRNA-based cancer therapeutic. The animal-model study demonstrated a marked suppression of a microRNA that was found to be over expressed in human hepato-cellular carcinoma (HCC), and a significant two-fold reduction of tumor mass.
These data are being presented at the Keystone Symposium, Therapeutic Modulation of RNA Using Oligonucleotides, at Lake Louise, Alberta Canada, on February 12th.
Liver cancer is the third cause of cancer death globally, affecting over 19,000 patients annually in the US alone. Prognosis is extremely grim, with nine out of ten patients dying within 5 years. Sorafenib (Nexavar®), the only oral anti-cancer drug currently approved for systemic therapy for HCC, extends survival by approximately 3 months.
Rosetta's scientists first identified miR-191, a microRNA that is abnormally over-expressed in human liver cancer cells, and which when inhibited effectively reduces cell proliferation and promotes cell-death of these liver tumor cells. The scientists then used an in-vivo model called Orthotopic Xenograft, in which an artificial tumor fragment derived from a human liver cancer cell line is transplanted into livers of mice, in order to evaluate the efficacy of systemic microRNA-based treatment in these mice.
Chemically modified antisense oligos (ASOs) were delivered systemically, targeting the over-expressed microRNA. Using this animal model, the scientists have shown that the targeted microRNA was markedly decreased in mice livers and was practically undetectable within the tumor itself, and that the tumor mass was significantly reduced two-fold, within 40 days of treatment.
Interestingly, the researchers showed that Dioxin, one of the most toxic substance ever identified and a known liver cancer carcinogen, markedly increases the expression of the targeted microRNA.
"We view this study as a landmark event in the development of microRNA based cancer therapeutics" said Amir Avniel, President and CEO of Rosetta Genomics. "While Rosetta's clear focus is on developing diagnostics, this collaborative project with Regulus is an example of how we intend to leverage the tremendous potential that microRNA holds in therapeutics and other domains. Every one of our diagnostic biomarkers is also a potential drug target, and we intend to form strategic alliances with suitable biopharma partners to leverage and commercialize these opportunities."