Valentis Licenses Delivery Technology to Juvaris BioTherapeutics

Burlingame, CA - May 21, 2003 /PRNewswire/
Valentis, Inc. (Nasdaq:VLTSC) and Juvaris BioTherapeutics announced today that they entered into a broad, non-exclusive licensing agreement in which Juvaris will use Valentis' proprietary plasmid backbone and cationic lipid delivery technologies for the development and commercialization of therapeutic vaccine products. Under terms of the agreement, Valentis will receive an initial cash payment from Juvaris and be eligible for future product development milestones and royalties on sales. Juvaris will be responsible for the development, manufacturing and commercialization of products and will bear all related program expenses. Further terms and financial considerations were not disclosed.

"Our agreement with Juvaris continues to validate both our technologies and our ability to execute a highly focused business strategy during these difficult financial markets," stated Benjamin F. McGraw, III, Chairman, President & CEO of Valentis. "We are investing our resources in our promising Del-1 angiogenesis product soon to begin Phase II clinical trials, while licensing proprietary delivery technologies to partners for use in the creation of additional products from which we may derive future milestones and royalties. We are pleased that Juvaris has chosen to work with us."

"We will initially use these proprietary lipid-DNA complexes to up regulate the immune system and as a delivery platform for antigens. Our substantial preclinical data supports this choice," said Martin D. Cleary, Co-founder, President and CEO of Juvaris, and added "This is also an important step in advancing our therapeutic vaccine program. The Valentis material has been in human clinical studies for gene therapy, and although ours is not a gene therapy application, we will access Valentis' manufacturing, quality and related data. This know how will shorten our time to the clinic and avoid having to start the process from scratch. This is a win/win for both companies. I am delighted we were able to come to this agreement."

About Valentis
Valentis is converting biologic discoveries into innovative products. The Company's lead product is based on the del-1 angiogenesis gene, formulated with one of the Company's PINC proprietary polymer delivery systems. The Company is developing its other technologies, the GeneSwitch®, cationic-lipid and DNA vaccine delivery technologies through partnerships with pharmaceutical and biotechnology companies. Additional information on the Company is available at http://www.valentis.com.

About Juvaris BioTherapeutics
Juvaris is a privately held therapeutic vaccine company, formed in 2002, which owns exclusive rights to novel technology platforms developed by one of its scientific founders at the National Jewish Medical and Research Center in Denver, Colorado. Given the demonstrated capabilities of its approach in extensive pre-clinical testing, the company believes this technology platform will lead to the development of superior therapeutic vaccines. Specific applications will include anti-bacterial, anti-viral and anti-cancer products. The Juvaris management team and its advisors have a proven track record in corporate venture financing; building shareholder value, and execution of strategies that realized substantial returns on investment for shareholders.

Statements in this press release that are not strictly historical are "forward-looking" statements as defined in the Private Securities Litigation Reform Act of 1995. The words "believes," "expects," "intends," "anticipates," variations of such words, and similar expressions identify forward-looking statements, but their absence does not mean that the statement is not forward-looking. These statements are not guarantees of future performance and are subject to certain risks, uncertainties and assumptions that are difficult to predict. Factors that could affect Valentis' actual results include the need for additional capital, the early stage of product development, uncertainties related to clinical trials, and uncertainties related to patent position. There can be no assurance that Valentis will be able to develop commercially viable gene-based therapeutics, that any of the Company's programs will be partnered with pharmaceutical companies, that necessary regulatory approvals will be obtained, or that any clinical trial will be successful. Actual results may differ from those projected in forward-looking statements due to risks and uncertainties that exist in the Company's operations and business environments. These are described more fully in the Valentis Annual Report on Form 10-K for the period ended June 30, 2002 and Quarterly Report on Form 10-Q for the period ended March 31, 2002, each as filed with the Securities and Exchange Commission.