AEterna Zentaris Inc. (NASDAQ: AEZS; TSX: AEZ) (the "Company"), a global biopharmaceutical company focused on endocrine therapy and oncology, announced positive efficacy data from a Phase 2 study with its targeted cytotoxic peptide conjugate, AEZS-108 (formerly AN-152), in patients with advanced or recurrent endometrial cancer. In a personalized health care approach, the study selected patients with tumors expressing luteinizing hormone-releasing hormone (LHRH) receptors, the key element in the targeting mechanism of AEZS-108. Under the coordination of Prof. Gunter Emons, MD, Chairman of the Department of Obstetrics & Gynaecology at the University of Gottingen, Germany, this open-label, multi-center and multi-national Phase 2 study AGO-GYN 5, is being conducted by the German AGO Study Group (Arbeitsgemeinschaft Gynakologische Onkologie/Gynaecological Oncology Working Group;), in cooperation with clinical sites in Europe.

Preliminary Results

A preliminary evaluation has shown that the study AGO-GYN 5 met its predefined primary efficacy endpoint of 5 or more responder patients with endometrial cancer. The study is currently ongoing, and responders, as well as patients with stable disease after completion of treatment with AEZS-108, will be followed to assess the duration of progression-free survival and, ultimately, overall survival. Detailed analyses of the study results will be presented at forthcoming scientific conferences.

Juergen Engel, Ph.D., President and Chief Executive Officer at AEterna Zentaris stated, "We are pleased with the progress of this Phase 2 program. Along with the recently disclosed positive results for the ovarian cancer indication, the good news for the endometrial cancer indication provides us with an even stronger basis to take the next steps in the development of AEZS-108 in gynaecological cancers."

About AEZS-108 and its Phase 2 program

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.

In a Phase 2 study program entitled, "The antitumoral activity and safety of AEZS-108 (AN-152), a LHRH agonist linked doxorubicin in women with LHRH-receptor positive gynaecological tumors", patients with tumors expressing LHRH receptors are administered an intravenous infusion of 267 mg/m2 of AEZS-108 over a period of 2 hours, every Day 1 of a 21-day (3-week) cycle. The proposed duration of the study treatment is 6, 3-week cycles.

Study AGO-GYN 5 is performed with 14 centers of the German Gynaecological Oncology Working Group (AGO; ago-ovar.de), in cooperation with 3 clinical sites in Europe.

The program was planned to include up to 82 evaluable patients, up to 41 with a diagnosis of platinum-resistant and taxane-pretreated ovarian cancer, (for which positive results were disclosed on November 2, 2009) and up to 41 with advanced or recurrent endometrial cancer. For both indications, patient recruitment was planned in 2 stages, with 21 and 20 patients, respectively, and the primary efficacy endpoint at the end of stage 2 was defined as 5 or more patients with partial or complete tumor responses according to Response Evaluation Criteria in Solid Tumors (RECIST) and/or Gynaecologic Cancer Intergroup (GCIG) guidelines. Secondary endpoints include time to progression, survival, toxicity as well as adverse effects.

About Endometrial and Ovarian Cancer

Cancer of the endometrium is the most common gynaecologic malignancy and accounts for 6% of all cancers in women. The majority of the cases occur in postmenopausal women, with the largest number of women developing their cancers during their sixth decade. Approximately 38,000 new cases and 9,000 deaths from this disease are estimated annually in Europe (