QUEBEC CITY, May 12 /PRNewswire-FirstCall/ – Aeterna Zentaris Inc. (NASDAQ: AEZS, TSX: AEZ) (the “Company”), a late-stage drug development company specialized in oncology and endocrine therapy, today announced that the U.S. Food and Drug Administration (FDA) has approved the Company’s Investigational New Drug (IND) application for its doxorubicin targeted conjugate compound, AEZS-108, in luteinizing hormone releasing hormone (LHRH) receptor positive urothelial (bladder) cancer. Following this approval from the FDA, the Company expects to initiate a Phase 2 clinical trial in this indication in the second half of this year.

The study will be conducted at the Sylvester Comprehensive Cancer Center at the University of Miami Miller School of Medicine with Gustavo Fernandez, M.D., Assistant Professor of Medicine, as the Principal Investigator, and will include up to 64 patients, male and female, with advanced LHRH-receptor positive urothelial (bladder) cancer. The study will be conducted in two parts; the first one will be a dose-finding part in up to 12 patients and then, the chosen dose will be studied for its effect on progression-free survival.

Juergen Engel, Ph.D., President and CEO of Aeterna Zentaris stated, “We are very pleased with the FDA’s approval and excited about this Phase 2 trial in bladder cancer, since it will be our first with AEZS-108 in the United States, and the first one to include male patients. With this upcoming Phase 2 trial, as well as the current Phase 2 trial in advanced ovarian and endometrial cancer conducted in Europe, for which final results are expected before year-end, AEZS-108 has become a major component of our oncology portfolio.”

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 Bladder Cancer

According to the National Cancer Institute, bladder cancer is the sixth most common type of cancer. In 2009, there were 70,980 new cases and 14,330 deaths from bladder cancer in the U.S. alone.

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.

SOURCE AETERNA ZENTARIS INC.