Aeterna Zentaris Presented Poster on Oral Prostate Cancer Vaccine, AEZS-120, at International Urology Conference in Japan

Filing of Clinical Trial Application (CTA) in Prostate Cancer Expected in Q4 2012

QUEBEC CITY, Oct. 2, 2012 /PRNewswire/ - Aeterna Zentaris Inc. (NASDAQ: AEZS) (TSX: AEZ) (the "Company") today announced that preclinical data on its oral prostate cancer vaccine candidate, AEZS-120, were presented over the weekend at the 32^nd Congress of the Société Internationale d'Urologie, which is being held in Fukuoka, Japan. The presentation underlined the feasibility of an oral therapeutic vaccination approach against prostate cancer. Furthermore, safety pharmacology and toxicology data suggest that the profile of AEZS-120 is similar to the approved carrier strain and, therefore, pave the way for Phase 1 clinical testing.

Juergen Engel, PhD, President and CEO at Aeterna Zentaris, commented, "Now that we have completed the preclinical development program for AEZS-120, we look forward to filing a Clinical Trial Application in Europe during this quarter, in order to initiate a Phase 1 clinical trial in prostate cancer with this novel oral anticancer vaccine."

Summary and Conclusions

The production, release, pharmacology, safety and toxicology program was conducted in agreement with the regulatory authorities and successfully finalized:

• The proof of concept has been shown in a tumor-challenge mouse model using the anticipated clinical application schedule;
• Biosafety and biodistribution studies did not reveal a different safety profile compared to the carrier strain;
• Pharmacological and toxicological studies did not reveal differences to the approved carrier strain;
• In all, the non-clinical studies suggest that the safety and toxicological profile of AEZ-120 is similar to the approved carrier strain S. typhi Ty21a, which has already been safely applied in more than 250 million doses;
• GMP material for clinical use has been produced and released; and CTA filing for Phase 1 clinical study is planned in 4Q 2012.

The poster titled, "Preclinical Proof of Concept and Characterization of AEZS-120, a Therapeutic Oral Prostate Cancer Vaccine Candidate Based on Live Recombinant Attenuated Salmonella", J. Fensterle, B. Bergmann, P. Schmidt, M. Teifel, J. Engel, T. Rudel, W. Goebel, and U. Rapp, can be viewed by clicking on the following link.

About AEZS-120

AEZS-120 is a live recombinant oral tumor vaccine candidate based on Salmonella typhi Ty21a as a carrier strain. Salmonella typhi Ty21a is an approved oral typhoid vaccine which has been safely applied in more than 250 million doses. The principle of AEZS-120 is based on the recombinant expression of prostate specific antigen fused to the B subunit of cholera toxin and a secretion signal in the presence of the Escherichia coli type I hemolysin secretion system. The proprietary system allows the secretion of the antigen, together with an immunological adjuvant which has been demonstrated to be required for optimal induction of CD8 T-cell responses by recombinant Salmonella based bacterial vaccines. The proof-of-concept was demonstrated for the mouse homologue of AEZS-120 in a mouse tumor-challenge model. In general, by varying the antigen and/or the carrier, this proprietary platform technology should be suitable for virtually any therapeutic or prophylactic vaccine indication with a favorable cost of goods expectation in large scale.

About Aeterna Zentaris

Aeterna Zentaris is an oncology and endocrinology drug development company currently investigating treatments for various unmet medical needs. The Company's pipeline encompasses compounds at all stages of development, from drug discovery through to marketed products. For more information please visit www.aezsinc.com.

Forward-Looking Statements

This press release contains forward-looking statements made pursuant to the safe harbour provisions of the U.S. Securities Litigation Reform Act of 1995. Forward-looking statements involve known and unknown risks and uncertainties that could cause the Company's actual results to differ materially from those in the forward-looking statements. Such risks and uncertainties include, among others, the availability of funds and resources to pursue R&D projects, the successful and timely completion of clinical studies, the risk that safety and efficacy data from any of our Phase 3 trials may not coincide with the data analyses from previously reported Phase 1 and/or Phase 2 clinical trials, the ability of the Company to take advantage of business opportunities in the pharmaceutical industry, uncertainties related to the regulatory process and general changes in economic conditions. Investors should consult the Company's quarterly and annual filings with the Canadian and U.S. securities commissions for additional information on risks and uncertainties relating to forward-looking statements. Investors are cautioned not to rely on these forward-looking statements. The Company does not undertake to update these forward-looking statements. We disclaim any obligation to update any such factors or to publicly announce the result of any revisions to any of the forward-looking statements contained herein to reflect future results, events or developments, unless required to do so by a governmental authority or by applicable law.

SOURCE AETERNA ZENTARIS INC.