Aeterna Zentaris (AEZS) Receives Orphan-Drug Designation from the FDA

QUEBEC CITY, May 6 /PRNewswire-FirstCall/ – Aeterna Zentaris Inc. (NASDAQ: AEZS, TSX: AEZ), (“the Company”) a late-stage drug development company specialized in oncology and endocrinology, today announced that it has received from the U.S. Food and Drug Administration (FDA), orphan-drug designation for AEZS-108, its doxorubicin targeted conjugate compound, for the treatment of ovarian cancer. AEZS-108 is currently in a Phase 2 trial in advanced ovarian and advanced endometrial cancer in Europe.

Juergen Engel, Ph. D., President and CEO of Aeterna Zentaris stated, “We are very pleased with AEZS-108 gaining orphan-drug designation for ovarian cancer from the FDA as it would provide it with extra market exclusivity protection. We look forward to reporting the final results from our ongoing European Phase 2 study in ovarian and endometrial cancer, later this year.”

About Orphan-Drug Designation

Orphan-drug designation is granted by the FDA Office of Orphan Products Development to novel drugs or biologics that treat a rare disease or condition affecting fewer than 200,000 patients in the U.S. The designation provides the drug developer with a seven-year period of U.S. marketing exclusivity if the drug is the first of its type approved for the specified indication or if it demonstrates superior safety, efficacy, or a major contribution to patient care versus another drug of its type previously granted the designation for the same indication. It also provides tax credits for clinical research costs, the ability to apply for annual grant funding, clinical research trial design assistance and waiver of Prescription Drug User Fee Act (PDUFA) filing fees.

About Ovarian Cancer

Ovarian cancer is one of the most common gynaecologic malignancies and the fifth most frequent cause of cancer death in women, with most of the cases occurring in women between 50 and 75 years of age. Overall, ovarian cancer accounts for 4% of all cancer diagnoses in women and 5% of all cancer deaths. Approximately 26,000 new cases and 17,000 deaths from this disease are estimated in the European community every year (Source: Gynaecologic Oncology 2004; 92:819-26). The National Cancer Institute estimates that in 2009, in the United States alone, there were 21,550 news cases of ovarian cancer and 14,600 related deaths.

About AEZS-108

AEZS-108 represents a new targeting concept in oncology using a cytotoxic peptide conjugate which is a hybrid molecule composed of a synthetic peptide carrier and a well-known cytotoxic agent, doxorubicin. The design of this product allows for the specific binding and selective uptake of the cytotoxic conjugate by LHRH-receptor-positive tumors. The binding of AEZS-108 to cancerous cells that express these receptors results in its accumulation and preferential uptake in the malignant tissue.

About Aeterna Zentaris Inc.

Aeterna Zentaris Inc. is a late-stage drug development company specialized in oncology and endocrine therapy. News releases and additional information are available at www.aezsinc.com.

Forward-Looking Statements

This press release contains forward-looking statements made pursuant to the safe harbor provisions of the U.S. Securities Litigation Reform Act of 1995. Forward-looking statements involve known and unknown risks and uncertainties, which 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 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 the 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 except if we are required by a governmental authority or applicable law.