Sirna Therapeutics Announces Receipt of Stockholder Approval for Final Proposal Put Forth at April 16th Special Stockholders' Meeting
  Monday April 28, 8:55 am ET 
  BOULDER, Colo., April 28 /PRNewswire-FirstCall/ -- Sirna Therapeutics, Inc. (Nasdaq: RNAI - News) announced today that it has received the requisite stockholder approval to amend its certificate of incorporation in order to increase the company's authorized capital stock. This proposal had been put forth before the special meeting of Sirna's stockholders held on April 16, 2003. The proposal had been adjourned and voting continued until April 25, 2003, at which point a favorable vote had been cast and tallied. Currently, the company has no plans relating to the issuance of these shares.   About Sirna Therapeutics
  Sirna Therapeutics (formerly Ribozyme Pharmaceuticals) is a biotechnology company leveraging its expertise in nucleic acid technology to develop and commercialize products that target human diseases. Sirna Therapeutics' primary focus is to develop therapeutics based on a nucleic acid technology called ribonucleic acid interference, or RNAi. In addition, with its partner Chiron, Sirna Therapeutics is developing an RNA-based therapeutic product, ANGIOZYME®, an anti-angiogenic agent in Phase II development for the treatment of metastatic colorectal cancer. The company also has expertise in oligonucleotide manufacturing. To date, Sirna Therapeutics has established strategic corporate relationships with Archemix Corporation, atugen AG, Chiron Corporation, Fujirebio, and Geron Corporation. Sirna Therapeutics is listed on the Nasdaq National Market under the ticker symbol "RNAI." More information on Sirna Therapeutics is available on the company's web site at www.sirna.com .
  This press release contains forward-looking statements that involve risks and uncertainties, and actual events or results may differ materially. These risk factors include actions by the U.S. Food and Drug Administration, technological advances, ability to obtain rights to technology, ability to obtain and enforce patents, ability to commercialize and manufacture products and general economic conditions. These and additional risk factors are identified in the company's Securities and Exchange Commission filings, including the Forms 10-K and 10-Q and in other SEC filings.
  For further information please contact: Howard W. Robin, President & CEO of Sirna Therapeutics, Inc., +1-303-449-6500; or Amy Sullivan, Senior Vice President of Noonan Russo Presence, +1-415-677-4455, for Sirna Therapeutics, Inc. 
  -------------------------------------------------------------------------------- Source: Sirna Therapeutics, Inc. |