MDRNA Reports Its Proprietary RNAi-Based Compounds Are Well Tolerated and Demonstrate High Potency Against Multiple

BOTHELL, WA, May 19 (MARKET WIRE) --
MDRNA, Inc. (NASDAQ: MRNA) announced today positive in vivo efficacy data
showing that its proprietary UsiRNA constructs are highly potent and
highly specific against ApoB and Factor VII message. The data are being
presented today by Michael V. Templin, Ph.D., Vice President, Discovery
Research and Pharmaceutical Development of MDRNA, at the TIDES
Oligonucleotide and Peptide(R) Technology and Product Development
Conference in Las Vegas, Nevada.

"Data from recent in vivo studies using our UsiRNAs targeting ApoB message
confirm that RNA interference is the mechanism of action by which
knockdown occurs, giving us high confidence that our UsiRNAs work by a
sequence-specific mechanism," stated Barry Polisky, Ph.D., Chief
Scientific Officer of MDRNA. "Data from the Factor VII studies indicate
that a siRNA in our lead formulation achieved greater than 90% knockdown
at 1 mg/kg with duration of effect of up to 28 days. This level of
inhibition and duration of effect meets or exceeds published data for
Factor VII."

Dr. Polisky added, "Data from rodent studies with our DiLA2 delivery
system also continue to show encouraging results, with potency,
specificity and duration of effect data now achieved for four independent
liver targets, including ApoB, PCSK9, DGAT2 and Factor VII. The absence
of histological changes in the liver with doses up to 9 mg/kg in rodents
confirms that our DiLA2 liposomes are well tolerated."

About UsiRNAs

UsiRNAs are duplex siRNAs that are modified with non-nucleotide acyclic
monomers, termed unlocked nucleobase analogs (UNA), in which the bond
between two adjacent carbon atoms of ribose is removed. UsiRNAs are fully
recognized by the RNAi machinery and provide for potent RNAi activity.
Placement of UNA within UsiRNA minimizes the potential for off-target
effects by the guide strand as well as undesired activity of the passenger
strand. Further, the change in sugar structure renders this unlocked
nucleobase analog conformationally flexible. The flexibility of the
monomer escapes the body's surveillance mechanisms associated with
cytokine induction, as well as providing protection from nuclease
degradation.

About the DiLA2 Delivery Platform

DiLA2 is MDRNA's proprietary platform technology for creating novel
liposomal delivery systems from amino acids. The platform enables MDRNA to
tailor the charge, linker and acyl chains of amino acids in order to
optimize the liposome for delivery to the target tissue of interest. In
addition, the platform is designed to permit attachment of various
peptides and other targeting molecules to improve a variety of delivery
characteristics. In addition, MDRNA is utilizing peptides for nanoparticle
formulations to increase cellular uptake and endosomal release.

About MDRNA, Inc.

MDRNA is a biotechnology company focused on the development and
commercialization of therapeutic products based on RNA interference
(RNAi). Our goal is to improve human health by combining novel RNAi-based
compounds and proprietary peptide- and liposomal-based drug delivery
technologies to provide superior therapeutic options. Our
multi-disciplinary portfolio of capabilities includes molecular biology,
cellular biology, formulation expertise, peptide and alkylated amino acid
chemistry, pharmacology, toxicology and bioinformatics. We are applying
this expertise to a single, integrated drug discovery platform that will
be the engine for our clinical pipeline and a versatile platform for
establishing broad therapeutic partnerships. We are also building on new
technologies, such as UsiRNAs that incorporate the non-nucleotide moiety
Unlocked Nucleobase Analog (UNA) within the siRNA molecule, that we
expect to lead to safer and more effective RNAi-based therapeutics. By
combining broad expertise in siRNA science with proven delivery platforms
and a strong and growing IP position, MDRNA is well positioned as a
leading RNAi therapeutics company and value-added collaborator for our
research partners. Additional information about MDRNA, Inc. is available
at http://www.mdrnainc.com.

MDRNA Forward-Looking Statement

Statements made in this news release may be forward-looking statements
within the meaning of Federal Securities laws that are subject to certain
risks and uncertainties and involve factors that may cause actual results
to differ materially from those projected or suggested. Factors that could
cause actual results to differ materially from those in forward-looking
statements include, but are not limited to: (i) the ability of MDRNA to
obtain additional funding; (ii) the ability of MDRNA to attract and/or
maintain manufacturing, research, development and commercialization
partners; (iii) the ability of MDRNA and/or a partner to successfully
complete product research and development, including preclinical and
clinical studies and commercialization; (iv) the ability of MDRNA and/or a
partner to obtain required governmental approvals; and (v) the ability of
MDRNA and/or a partner to develop and commercialize products that can
compete favorably with those of competitors. Additional factors that could
cause actual results to differ materially from those projected or
suggested in any forward-looking statements are contained in MDRNA's most
recent periodic reports on Form 10-K and Form 10-Q that are filed with the
Securities and Exchange Commission. MDRNA assumes no obligation to update
and supplement forward-looking statements because of subsequent events.

CONTACT

Matthew D. Haines
Senior Director, Investor Relations and Corporate Communications
(212) 209-3874
Email Contact

McKinney|Chicago (Media)
Alan Zachary
(312) 944-6784 x 316 or
(708) 707-6834
Email Contact

Copyright 2009, Market Wire, All rights reserved.

-0-