Aeterna Zentaris Announces Initiation of Phase 3 Registration Trial with Perifosine in Refractory Advanced Colorectal Cancer

Phase 3 X-PECT Trial (Xeloda(R)) + Perifosine Evaluation in Colorectal Cancer Treatment) being conducted by partner Keryx Biopharmaceuticals pursuant to Special Protocol Assessment with the Food and Drug Administration

QUEBEC CITY, April 8 /PRNewswire-FirstCall/ - Æterna Zentaris Inc. (NASDAQ: AEZS, TSX: AEZ) (the "Company"), a late-stage drug development company specialized in oncology and endocrine therapy, today announced the initiation of a Phase 3 registration clinical trial with perifosine (KRX-0401) ), the Company's novel, potentially first-in-class, oral anti-cancer agent that inhibits Akt activation in the phosphoinositide 3-kinase (PI3K) pathway, for the treatment of refractory advanced colorectal cancer. The trial is sponsored and conducted by Keryx Biopharmaceuticals ("Keryx") (Nasdaq: KERX), Æterna Zentaris' partner and licensee for perifosine in the United States, Canada and Mexico. Æterna Zentaris has also out-licensed perifosine to Handok in South Korea, while retaining rights for the rest of the world.

The Phase 3 trial, entitled "X-PECT (Xeloda(R) + Perifosine Evaluation in Colorectal cancer Treatment) trial", is being conducted pursuant to a Special Protocol Assessment ("SPA") with the Food and Drug Administration. Perifosine has also been granted Fast Track designation for the treatment of refractory advanced colorectal cancer. Approximately 40 to 50 U.S. sites will participate in the study. Keryx expects enrollment to take approximately 12 - 14 months, with study completion expected in the second half of 2011.

Dr. Johanna Bendell, Director of GI Oncology Research for the Sarah Cannon Research Institute, Nashville, Tennessee, will lead the Phase 3 investigational team that includes Dr. Cathy Eng, Associate Medical Director for the Colorectal Center at MD Anderson Cancer Center in Houston, Texas.

Juergen Engel, Ph.D., President and Chief Executive Officer of Æterna Zentaris, commented, "We are very pleased with the initiation and sponsorship of this key registration Phase 3 trial in refractory advanced colorectal cancer in North America which our partner Keryx expects to complete in the second half of 2011, with product launch, in the USA, in 2012. These data will be very supportive of our efforts to register perifosine in the rest of the world, where in some countries, we expect they will be sufficient to do so without any additional studies."

Phase 3 Trial Design

The Phase 3 X-PECT (Xeloda(R) + Perifosine Evaluation in Colorectal cancer Treatment) trial is a randomized (1:1), double-blind trial comparing the efficacy and safety of perifosine + capecitabine (capecitabine is a chemotherapy marketed by Roche as Xeloda(R)) vs. placebo + capecitabine in approximately 430 patients with refractory advanced colorectal cancer. Patients must have failed available therapy including 5-fluorouracil (5-FU), oxaliplatin (Eloxatin(R)), irinotecan (Camptosar(R)), bevacizumab (Avastin(R)) and, if KRAS wild-type, failed therapy with prior cetuximab (Erbitux(R)) or panitumumab (Vectibix(R)). For oxaliplatin-based therapy, failure of therapy will also include patients who discontinued due to toxicity. The primary endpoint is overall survival, with secondary endpoints including overall response rate (complete + partial responses), progression-free survival and safety. The median overall survival for the X-PECT study's targeted patient population, that has failed prior therapies as described above, is approximately 5 months. The X-PECT study will be powered at 90% to detect a statistically significant difference in overall survival, with an assumed median overall survival for the control arm of 5-6 months and 7-8 months for the perifosine arm. Approximately 360 events of death will trigger the unblinding of the study.

About Perifosine

Perifosine is a novel, potentially first-in-class, oral anti-cancer agent that modulates Akt, and a number of other key signal transduction pathways, including the JNK and MAPK pathways, all of which are pathways associated with programmed cell death, cell growth, cell differentiation and cell survival. The effects of perifosine on Akt are of particular interest because of the importance of this pathway in the development of most cancers, with evidence that it is often activated in tumors that are resistant to other forms of anticancer therapy, and the difficulty encountered thus far in the discovery of drugs that will inhibit this pathway without causing excessive toxicity. High levels of activated Akt (pAkt) are seen frequently in many types of cancer and have been correlated with poor prognosis.

About Colorectal Cancer

According to the American Cancer Society, colorectal cancer is the third most common form of cancer diagnosed in the United States. It is estimated that over 146,000 people were diagnosed with some form of colorectal cancer with over 49,000 patients dying from colorectal cancer in 2009. Surgery is often the main treatment for early stage colorectal cancer. When colorectal cancer metastasizes (spreads to other parts of the body such as the liver) chemotherapy is commonly used. Treatment of patients with recurrent or advanced colorectal cancer depends on the location of the disease. Chemotherapy regimens (i.e. FOLFOX or FOLFIRI either with or without bevacizumab) have been shown to increase survival rates in patients with metastatic/advanced colorectal cancer. Currently, there are seven approved drugs for patients with metastatic colorectal cancer: 5-fluorouracil (5-FU), capecitabine (Xeloda(R)), irinotecan (Camptosar(R)), oxaliplatin (Eloxatin(R)), bevacizumab (Avastin(R)), cetuximab (Erbitux(R)), and panitumumab (Vectibix(R)). Depending on the stage of the cancer, two or more of these types of treatment may be combined at the same time or used after one another. For example, FOLFOX combines 5-FU, leucovorin and oxaliplatin and FOLFIRI combines 5-FU, leucovorin and irinotecan. Bevacizumab, a VEGF monoclonal antibody, is commonly administered with chemotherapy. Typically, patients who fail 5-FU, oxaliplatin, irinotecan, and bevacizumab-containing therapies, and who have wild-type KRAS status receive EGFR monoclonal antibody therapy with either cetuximab or panitumumab. Once patients progress on these agents, there are no further standard treatment options.

About Æterna Zentaris Inc.

Æterna 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.