MDRNA, Inc announced that it now has full financial and transactional control over the use of its proprietary UNA (Unlocked Nucleobase Analog) technology for the development of RNAi-based therapeutics. The company completed negotiations with RiboTask ApS to eliminate all downstream financial consideration to RiboTask resulting from collaborations established between MDRNA and potential pharmaceutical and biotechnology partners. Terms of this Amendment to their May 2008 Agreement were not disclosed.

UNA, when used in the synthesis of a short-interfering RNA (UsiRNA), provides drug-like properties to a siRNA in a novel and proprietary manner; these include protection from enzymatic destruction; reduction, or elimination, of a cytokine response; and preservation of high efficacy. The use of UsiRNA as RNAi-based therapeutics has the potential for both effective protein down regulation with lower total doses of siRNA and an improved safety profile.

"In pre-clinical studies we have completed over the past 12 months, our proprietary UsiRNA constructs have been shown to increase stability, reduce off-target activity and cytokine induction, and improve gene silencing. These characteristics are key to human therapeutic use of UsiRNA and, when formulated with our DilA2 delivery technology, provide a powerful approach to down regulating protein expression via RNAi," stated J Michael French, president and CEO of MDRNA. "We believe that amending the IP assignment agreement at this time provides us greater flexibility to complete broad target and therapeutic based collaborations with major pharmaceutical companies."

In October 2008, MDRNA completed the acquisition of the patent portfolio related to UNA from RiboTask via an intellectual property assignment agreement, which included certain financial obligations payable by MDRNA to RiboTask in the event of a license, development or sale of UNA-based siRNA for human therapeutic use. Under the renegotiated terms, all future financial obligations payable by MDRNA to RiboTask were eliminated. RiboTask retains rights to manufacture, sell and sublicense UNA technology for use in reagents and diagnostics only.

French added, "MDRNA and RiboTask have enjoyed a strong and mutually rewarding partnership. I would like to recognize and thank Dr Jesper Wengel, Suzy Lena and their colleagues at RiboTask, as well as our own scientists, for the tremendous work they have done to rapidly advance this promising technology. We look forward to a continued partnership with Dr. Wengel and his team."

Unlocked Nucleobase Analog (UNA) is an acyclic ribonucleoside analog having an open sugar ring structure.

UsiRNAs are UNA modified duplex siRNAs in which the bond between two adjacent carbon atoms of ribose is removed.

The DiLA2 Platform is MDRNA's proprietary platform for creating novel liposomal delivery systems from amino acids.

MDRNA is a biotechnology company focused on the development and commercialization of therapeutic products based on RNA interference (RNAi).