Roche and Mirus Bio Corporation announced that they have entered into a definitive agreement under which Roche will acquire Mirus Bio Corporation, a privately-owned US company based in Madison, Wisconsin, that focuses on the discovery and development of innovative nucleic acid based technologies, including a proprietary RNAi (Ribonucleic Acid interference) delivery platform.

RNAi - a natural mechanism that the body uses to 'silence' certain genes - represents a potential whole new class of therapeutics for difficult to treat diseases. The major challenge of this promising technology has so far been the transport of RNAi molecules into the target cell. Mirus' delivery platform provides an innovative way of effectively getting RNAi therapeutics to specific disease targets.

Roche's mission is to find novel solutions for patients who suffer from difficult to treat diseases. RNAi therapeutics provides the capabilities to target complex diseases such as cancer, respiratory or metabolic disorders. In 2007, Roche already announced a major alliance with the US-based company Alnylam Pharmaceuticals, Inc., which included the acquisition of Alnylam's European research site located in Kulmbach, Germany. This is now Roche's established Centre of Excellence for RNAi therapeutic research.

Under the terms of the agreement, Roche will fully acquire Mirus for USD 125 million and will maintain an RNAi research site in Madison. Mirus' transfection reagents business will be divested into a standalone business to be known as Mirus Bio LLC, without any anticipated effect on existing customers. Employees will be offered a transition into their respective business unit. Closing of the transaction is subject to standard conditions. Completion is expected during the second half of 2008.

"The pioneering work in RNAi delivery by the scientists at Mirus, together with our Centre of Excellence for RNAi research in Kulmbach, puts Roche at the forefront of bringing this whole new class of treatment to patients who suffer from difficult to treat diseases," said Lee E. Babiss, Global Head of Roche Pharma Research. "Our global research team has made great strides in advancing RNAi therapeutics, and with our new colleagues in Madison we will now bolster those efforts. The technology brought by Mirus, together with additional technologies, will bring us closer to creating fully enabled RNAi therapeutics."

"The expertise, resources and commitment that Roche brings to the RNAi field make Roche an ideal partner for Mirus," said Russell R. Smestad, president of Mirus. "Together we will be able to greatly accelerate the progress we would have accomplished independently."

RNAi (RNA interference) is a revolution in biology, representing a breakthrough in understanding how genes are turned on and off in cells. Its discovery was awarded the Nobel Prize in October 2006. By harnessing the natural biological process of RNAi occurring in our cells, the creation of a major new class of medicines, known as RNAi therapeutics, is on the horizon. RNAi therapeutics targets the cause of diseases by potently silencing specific messenger RNAs (mRNAs), thereby preventing disease-causing proteins from being made. RNAi therapeutics has the potential to treat disease and help patients in a fundamentally new way.