The momentum in the microRNA (miRNA) field is continuing to build, as evidence that links this group of important genes to multiple diseases, from Alzheimer to diabetes, is constantly mounting. The adoption of miRNAs is further accelerated by the technological advancements in RNA-based therapies. Because miRNAs are not expressed as proteins but as RNA, the most sensible way to target them is using small RNA technologies from the likes of Isis (ISIS) and Alnylam (ALNY). These technologies have come a long way in recent years, and are now expected to form the basis for a new generation of drugs. Although miRNAs gained wide recognition only recently, the combination of a fresh pool of unexplored genes which are implicated in so many medical conditions together with the maturing technology to manipulate their activity creates a huge untapped market.

So far, 2008 has been particularly fertile, with several exciting events taking place during recent months.

The news flow started last April, when Rosetta Genomics (ROSG) announced it had submitted, jointly with Columbia University Medical Center (CUMC), its first diagnostic test for regulatory approval. The test distinguishes between squamous and non-squamous lung cancer, a classification that has become very important following the introduction of Avastin^® and other targeted therapies.

Later that month, GlaxoSmithKline (GSK) and Regulus Therapeutics, a joint venture of Isis and Alnylam, announced a strategic alliance for the development of novel microRNA-targeted drugs for inflammatory diseases. The first of its kind in the miRNA field, the deal includes all the typical ingredients such as an upfront payment, milestone payments based on progress and royalties from future sales. The deal is worth $600 million, excluding future royalties, and denotes the tremendous appetite in the pharmaceutical industry for miRNAs. Given the constant increase in the attention miRNA are garnering, it would not be surprising to see similar deals in the future.

Only one week after the Regulus announcement, Asuragen launched the first-ever miRNA based diagnostic test, beating both Rosetta Genomics and Exiqon. The test is designed to differentiate between pancreatic cancer and pancreatitis (inflammation of the pancreas), which often have similar symptoms. Asuragen quoted a blinded trial in which 60 samples from patients were evaluated by the new assay.