RNA Therapeutics

With the launch of an independent joint venture called Regulus Therapeutics, Isis Pharmaceuticals and Alnylam Pharmaceuticals hope to become a force in the emerging field of therapeutics that target microRNAs. Both firms will contribute intellectual property, technology, and expertise in microRNAs to Regulus, and Alnylam will lay out $10 million in initial funding. Future funding will come equally from Isis and Alnylam.

MicroRNAs are small, single-stranded RNAs that are about 20 nucleotides in length. They serve as the gatekeepers for messenger RNAs, regulating mRNAs' ability to relay the instructions for protein production to their intended targets. The roughly 500 microRNAs that have been identified are believed to regulate expression of one-third of all human genes, according to Isis CEO Stanley Crooke.

The ubiquity of microRNAs, as well as their ability to broadly modulate disease, has quickly made them an intriguing therapeutic target. "Antagonism of microRNA defines a new strategy to target multiple points in entire pathways in human disease, not just single disease targets," Crooke said during a conference call to discuss Regulus.

Though it often takes decades to translate the identification of new drug targets into actual drugs, Isis and Alnylam believe the timeline for developing microRNA therapeutics could be significantly abbreviated. Regulus will benefit from Isis' expertise in making second-generation antisense compounds, which the companies say is "the ideal class of drugs" to inhibit microRNAs.

The new company's most advanced drug candidate targets miR-122, a microRNA implicated in hepatitis C. So far, Regulus' competition is limited. Israel-based Rosetta Genomics and Sirna Therapeutics, which was acquired last year by Merck & Co., are also vying for a position in the burgeoning field.