AEterna Zentaris Reaches 2nd Stage of Patient Recruitment for Phase 2 Trial in Endometrial Cancer with the Innovative LHRH Receptor Targeted Conjugate, AEZS-108

QUEBEC CITY, Nov. 3 /PRNewswire-FirstCall/ - AEterna Zentaris Inc. , a global biopharmaceutical company focused on endocrine therapy and oncology, today reported that it has entered the second stage of patient recruitment for its Phase 2 trial in endometrial cancer with AEZS-108, a luteinizing hormone-releasing hormone (LHRH) agonist linked to doxorubicin. The decision to enter the second stage of patient recruitment was taken following recent first stage data reporting 1 complete response (CR) and 2 partial responses (PR) among 14 patients with a diagnosis of disseminated endometrial cancer. The trial is part of a Phase 2 program in gynaecological cancers for which patient enrolment began in December 2007. The open-label, non-comparative multi-center Phase 2 program will treat up to 82 women with LHRH-receptor positive ovarian and endometrial cancerous tumors. The primary endpoint for the program is the partial or complete tumor response rate according to Response Evaluation Criteria in Solid Tumors (RECIST) and/or Gynaecologic Cancer Intergroup (GCIG) guidelines. The program is being conducted in 15 centers in Europe under the supervision of lead investigator, Prof. Günter Emons, M.D., of the Georg-August-University, Institute of Gynaecology and Obstetrics in Göttingen, Germany.

On October 2, 2008, the Company announced it had entered the second stage of patient recruitment, this time for the Phase 2 trial in ovarian cancer of this very same program, after first stage data had shown two partial responses (PR).

Paul Blake, M.D., Senior Vice President and Chief Medical Officer of AEterna Zentaris commented, "We are very pleased with this additional data on the early signal of potential efficacy of our lead oncology compound, AEZS-108 in both endometrial and ovarian cancer. The data also strengthens our belief that increased clinical benefit for patients could be achieved by specifically targeting LHRH-receptor expressing tumors using doxorubicin. Finally, this program remains on track and we expect to disclose full results over the next few months."

About the Phase 2 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", this European open-label, non-comparative multi-center Phase 2 program has as its primary endpoint, the partial or complete tumor response rate according to RECIST and/or GCIG guidelines. Secondary endpoints include time to progression, survival, toxicity as well as adverse effects. The program will include up to 82 patients (up to 41 with a diagnosis of platinum-resistant ovarian cancer and up to 41 with disseminated endometrial cancer). Patients are administered an intravenous infusion of 267 mg/m2 of AEZS-108 over a period of 2 hours at a constant rate, every Day 1 of a 21-day (3-week) cycle. The proposed duration of the study treatment is six, three-week cycles. Further information on the program is available at www.clinicaltrials.gov.

Prior Phase 1 trial results

On June 3, 2007 positive results of an open, multi-center, sequential group, dose-escalation Phase 1 study in various gynaecological cancers were presented at the American Society of Clinical Oncology's (ASCO) Annual Meeting in Chicago, Illinois. 17 patients with LHRH-receptor positive gynaecological cancers were recruited. AEZS-108 was administered by intravenous infusion over two hours at dosages of 10, 20, 40, 80,160 and 267 mg/m2. At 160 mg/m2, six patients had a total of 32 cycles and at 267 mg/m2, seven patients had a total of 27 cycles. Most of the patients had been pretreated with various chemotherapies.

The study showed that AEZS-108 was well tolerated by patients with gynaecological tumors. Furthermore, AEZS-108 is the first drug in a clinical study that targets the cytotoxic activity of doxorubicin specifically to LHRH-receptor expressing tumors. Finally, signs of anti-tumor activity were observed in 7 out of 13 patients treated with 160 or 267 mg/m2 of AEZS-108, including three patients with complete or partial response.

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 in the malignant tissue. This binding is followed by internalization and retention of the cytotoxic drug, doxorubicin, in the cells. Therefore, since they target specific cells, cytotoxic conjugates are postulated to be less toxic, have less side-effects and are more effective in vivo than the respective non-conjugated/non-linked cytotoxic agents in inhibiting tumor growth.

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 the sixth decade. Approximately 38,000 new cases and 9,000 deaths from this disease are estimated annually in Europe (Source: Annals of Oncology 15:1149-1150, 2004).

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 diagnosis 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: Gynecologic Oncology, Volume 92, Issue 3, March 2004, Pages 819-826).

About AEterna Zentaris Inc.

AEterna Zentaris Inc. is a global biopharmaceutical company focused on endocrine therapy and oncology with proven expertise in drug discovery, development and commercialization.

News releases and additional information are available at www.aeternazentaris.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 requested by a governmental authority or applicable law.

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