a s c e n i o n: Novel Class of Natural Products to be Developed as Anti-Cancer Therapeutics

Novel Class of Natural Products to be Developed as Anti-Cancer Therapeutics

Ascenion mediates licence agreement between GBF and Zentaris

Munich, July 06, 2004 – Ascenion GmbH has mediated a licence agreement between the German Research Centre for Biotechnology mbH (GBF) and Zentaris GmbH, German subsidiary of listed Æterna Zentaris Inc. (TSX: AEZ; NASDAQ: AEZS). The licence grants Zentaris exclusive worldwide rights for the development, manufacture and marketing of disorazoles, a novel class of natural products with strong anti-cancer potential discovered by GBF researchers. The agreement also provides Zentaris with access to GBF’s know-how in the field of disorazoles and includes a licence to the strain of bacteria producing the product. The deal builds on an option Zentaris had already secured for the class of disorazoles in 2002.

Under the terms of the agreement, the GBF will obtain an upfront fee and annual licence fees from Zentaris as well as milestone and royalty payments in line with product progress and future commercialization.

In the course of the screening of soil bacteria, GBF researchers have discovered that disorazol is a powerful inhibitor of the tubulin system, with a similar mode of action to taxol and vinblastin, the active ingredients of some of the world’s best selling anti-cancer drugs. Following the results of in-vitro studies recently published in the Journal of Biochemical Pharmacology , disorazol shows remarkably high cytostatic activity. At extremely low doses, it inhibits the proliferation of a broad range of cancer cell lines including multidrug-resistant cells.

“Zentaris has a strong track record in the development of novel cytostatic agents and is an ideal partner to take this powerful class of compounds forward and make it available to cancer patients,” Dr. Christian Stein, CEO of Ascenion comments.

“Securing rights to GBF’s exciting compound is yet another proof of our excellent network of scientific collaborations. Next to focussing on our own internal drug discovery unit, Zentaris has always been pursuing close contacts to the scientific world in order to secure a constant stream of promising product candidates,” says Prof. Dr. Jürgen Engel, Chairman and Managing Director of Zentaris GmbH and COO of Æterna Zentaris Inc.

Notes to Editors

About Ascenion GmbH

Ascenion is an agency for intellectual property management exclusively focused on life sciences. Ascenion supports and advises scientists and research institutions with regard to the protection and exploitation of their intellectual property (patents), and initiates and mediates licence agreements between research institutions and industry. Among Ascenion′s particular strengths are start-up coaching and active investment management. Since its foundation in 2001, Ascenion has mediated in over 60 agreements and currently holds equity in eight life-science companies.

Ascenion is a 100% subsidiary of the Life-Science Foundation for the Promotion of Science and Research and the exclusive commercialization partner for the GBF, GSF, MDC and DKZF*. Ascenion′s headquarters are in Munich, with further offices in Berlin, Braunschweig and Neuherberg.

* for the DKFZ, only in relation to findings from the NGFN (National Genome Research Network)

About Zentaris GmbH

Zentaris GmbH, a 100% subsidiary of Canadian Æterna Zentaris Inc., is an integrated clinical-research driven Biopharmaceutical Company with a clear focus on the treatment of benign and malignant tumors. With two product on the market, seven products in clinical and eight products in pre-clinical development it is one of the leading European biopharmaceutical companies. Following its guiding principle "committed to cure", 89 employees of Zentaris are developing in Frankfurt am Main innovative biopharmaceuticals for new patient-friendly therapies. For more information on Zentaris visit the web site at www.zentaris.com or visit Æterna Zentaris web site at www.aeternazentaris.com.