Washington, D.C. 20549

                            REPORT OF FOREIGN ISSUER

                      Pursuant to Rule 13a-16 or 15d-16 of
                       the Securities Exchange Act of 1934

                           For the month of March 2005

                              AETERNA ZENTARIS INC.
                    (Formerly named AEterna Laboratories Inc.)

                        1405, boul. du Parc-Technologique
                                 Quebec, Quebec
                                 Canada, G1P 4P5
                    (Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports
under cover of Form 20-F or Form 40-F.

                Form 20-F        Form 40-F    X  
                          ------           ------

Indicate by check mark whether the registrant by furnishing the information
contained in this Form is also thereby furnishing the information to the
Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934

                       Yes         No   X  
                           -----      -----

If "Yes" is marked, indicate below the file number assigned to the registrant in
connection with Rule 12g3-2(b): 82-____

                                 DOCUMENTS INDEX

Documents Description

1.              Press release dated March 16, 2005 - AEterna Zentaris 
                Announces Cetrorelix Development with Solvay Continues with 
                Endometriosis as a Primary Indication

                                                       [AETERNA ZENTARIS LOGO]

AETERNA ZENTARIS INC. 1405 du Parc-Technologique Blvd.
Quebec (Quebec) Canada  G1P 4P5  T 418 652-8525  F 418 652-0881

                                                          PRESS RELEASE
                                                          For immediate release


QUEBEC CITY, CANADA, MARCH 16, 2005 - AEterna Zentaris Inc. (TSX: AEZ; NASDAQ:
AEZS) today announced that the upcoming Phase III program with cetrorelix, a
luteinizing hormone-releasing hormone (LHRH) antagonist, will be conducted in
endometriosis as a primary indication. This will be achieved through
collaboration with Solvay Pharmaceuticals, the Company's worldwide (ex-Japan)
exclusive development and marketing partner for cetrorelix.

This decision was made following the successful completion of a broad seven
Phase II trial program of cetrorelix in endometriosis, benign prostate
hyperplasia and uterine myoma. It also takes into account recommendations from a
thorough market research program showing that endometriosis is still an area of
high unmet medical needs. An improved side effects profile, absence of hormonal
castration, convenience of dosing, suitability for long-term use as an
intermittent treatment and speed of onset of action are among key attributes
that could favorably position cetrorelix.

"The striking results we have seen with cetrorelix in Phase II trials,
particularly in endometriosis, deliver on the promise of LHRH antagonists and
are the culmination of our many years of research and development efforts into
LHRH and its antagonists domain conducted along with Nobel Laureate Prof. Andrew
Schally", said Prof. Jurgen Engel, Executive Vice President Global R&D and Chief
Operating Officer at AEterna Zentaris. "We are excited to see the strong
commitment of Solvay towards cetrorelix, our lead compound in endocrinology."

In light of the decision, Dr. Werner Cautreels, Solvay Pharmaceuticals' Chief
Executive Officer, confirmed: "We continue to strengthen our pipeline including
a strong Business Unit in Women Health which now includes cetrorelix as a key
asset. Given the exciting positive Phase II results obtained with cetrorelix in
endometriosis and the very favorable profile of this compound, we are putting
everything in place to complete the full development of this novel therapeutic
and to expedite the registration of cetrorelix to maintain our leadership
position in the women's health market. Although we never comment on the costs of
individual projects that are ongoing, typical industry figures for the costs
from here going forward of one successful full development program run into many
tens of millions of dollars."

According to Gilles Gagnon, President and Chief Executive Officer at AEterna
Zentaris: "We are very excited about this decision of Solvay Pharmaceuticals to
invest heavily in our Company by going ahead with cetrorelix in endometriosis as
the upcoming Phase III indication. At AEterna Zentaris, while we are working
towards the development of a fully-integrated company, we are 

now in a position to propose a pipeline encompassing  promising products at
all development  stages to continue to deliver benefits to patients and value to
our shareholders."

Endometriosis is the growth of the endometrium, or the inside lining of the
uterus, outside of the uterus and is dependent upon the level of estrogens.
Endometriosis affects approximately 10% to 20% of women of child-bearing age.
The total market size is estimated to be around US$800 million.


Solvay Pharmaceuticals is a member of the Solvay group of pharmaceutical and
chemical companies. Operating globally with corporate offices in Europe, the
U.S. and Japan, and sales and marketing companies in more than 45 countries,
Solvay Pharmaceuticals employs 8,000 people worldwide. It has research and
development activities concentrated onto carefully selected clinical targets in
the fields of women's and men's health, mental health, gastroenterology,
influenza prevention and cardiology. The Solvay Group employs about 30,000
people in three sectors of activity: pharmaceuticals, chemicals and plastics.
For further information on Solvay, please visit the website or


AEterna Zentaris Inc. is an oncology and endocrine therapy focused
biopharmaceutical company with proven expertise in drug discovery, development
and commercialization. The Company's broad 20 product pipeline leverages five
different therapeutic approaches, including LHRH antagonists and signal
transduction inhibitors. The lead LHRH antagonist compound, cetrorelix, is
currently marketed for IN vitro fertilization under the brand name Cetrotide(R),
and has successfully completed a broad Phase II program in endometriosis and
benign prostatic hyperplasia (BPH). The lead signal transduction inhibitor
compound, perifosine, is an orally-active AKT inhibitor that is in several 
Phase II trials for multiple cancers.

AEterna  Zentaris  owns  61.1% of Atrium  Biotechnologies  Inc.,  a leading
developer,  manufacturer and marketer of value-added products for the cosmetics,
pharmaceutical, chemical and nutritional industries.

News releases and additional information about AEterna Zentaris are available on
its Web site


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




Paul Burroughs
(418) 652-8525 ext. 406

Ginette Vallieres
(418) 652-8525 ext. 265


Matthias Seeber


             Pursuant to the requirements of the Securities Exchange Act of
1934, the registrant has duly caused this report to be signed on its behalf by
the undersigned, thereunto duly authorized.

                                      AETERNA ZENTARIS INC.

Date:  March 17, 2005                 By:  /s/Mario Paradis                   
---------------------                    --------------------------------------
                                           Mario Paradis
                                           Senior Finance Director and 
                                           Corporate Secretary