Silence and Mirna Partner to Evaluate Delivery Systems for miRNA Therapeutics

Silence Therapeutics and Mirna Therapeutics inked a collaboration to evaluate the use of Silence’s vascular endothelium-targeting AtuPlex™ and liver-targeting DBTC delivery systems for use with selected Mirna miRNA sequences. Under terms of the agreement, Mirna will provide Silence with specific miRNA sequences, which the latter will formulate using its delivery platforms into multiple drug candidates. Mirna will then carry out in vitro and in vivo studies and select lead candidates for further evaluation.

“This is our second collaboration exploring the use of Silence’s delivery technologies to deliver miRNAs,” comments Thomas Christely, CEO. “However, it is Silence’s first collaboration involving our new DBTC liver delivery system. While internally we remain focused on the delivery of our siRNA therapies, we continue to look to broaden the potential value of our delivery systems by partnering them with other companies for use in multiple applications.”

Silence’s lipid-based DBTC platform is its latest delivery system, and has been developed to enable functional targeted delivery to liver cells, including endothelial cells and hepatocytes. The AtuPlex lipid delivery technology is based on AtuFect lipid components that embed siRNA into multiple lipid bilayer structures. The resulting nanoparticles thus comprise the siRNA combined with a cationic lipid, fusiogenic lipid, and PEG.  

The technology has demonstrated broad systemic delivery to the vascular endothelium, the firm claims, and has the added benefit that formulations generated using AtuPlex can be lyophilized to improve stability, handling, and storage. Silence is currently carrying out a Phase I study with its own siRNA anticancer candidate, Atu027, which is based on the AtuPlex platform. Additional AtuRNAi candidates are in clinical development in partnership with Pfizer, Quark, and Novartis.

Mirna is developing a pipeline of anticancer miRNAs designed to replace a missing tumor suppressor miRNA by introducing a mimic that functions similarly to the endogenous miRNA and modulates the entire spectrum of genes and pathways that is also controlled in normal cells by the endogenous miRNA. The firm’s lead preclinical candidates include let-7 mimics and miR-34 candidates. Mirna is currently progressing several potential miR-34 mimics toward the clinic for the treatment of solid tumors. The let-7 program is targeting lung cancer, and potentially other cancers including prostate and acute myeloid leukemia.