AEZS

Aeterna Zentaris Inc. (NASDAQ: AEZS) (TSX: AEZS) (“Aeterna” or the “Company”), a specialty biopharmaceutical company developing and commercializing a diversified portfolio of pharmaceutical and diagnostic products, today announced that results from pre-clinical studies of Aeterna’s AIM Biologicals (Autoimmunity Modifying Biologicals) for the potential treatment of neuromyelitis optica spectrum disorder (“NMOSD”) were accepted for presentation at the 13th International Congress on Autoimmunity to be held June 10-13, 2022 in Athens, Greece.

The accepted abstract was selected for a poster presentation and an oral presentation at the Congress, which will be given by Aeterna’s research collaborator, Valentin Bruttel, PhD, Senior Researcher, Department of Obstetrics and Gynecology, School of Medicine, University of Wuerzburg (“the University”). Details of the abstract and presentations are as follows:

Title: Antigen presentation on MHC class Ib-related molecules induces Aquaporin4-specific regulatory T cells in PBMC from NMOSD patients and prevents experimental autoimmune encephalomyelitis in mice

Poster Presentation

Date and time: Poster will be displayed during the whole congress

Location: Exhibit space, Megaron Athens International Conference Centre, (MAICC), Athens, Greece

Oral Presentation

Track: Parallel Session 12 - CNS - Central Nervous System (ID 25)Date and time: Sunday, June 12, 2022, at 12:10 – 12:20

Location: Room “Nikos Skalkatos”, Megaron Athens International Conference Centre (MAICC), Athens, Greece

The abstract can be accessed under the following link:https://cslide.ctimeetingtech.com/auto22/attendee/confcal/show/session/25

“We are pleased that this abstract has been accepted for presentation at such a prestigious auto-immunity conference, considered to be the largest multidisciplinary congress that discusses all aspects of auto-immunity diseases, and which attracts some of the world’s most distinguished experts in auto-immunity”, commented Dr. Klaus Paulini, Chief Executive Officer of Aeterna. “In collaboration with Aeterna, Dr. Bruttel, Prof. Dr. Wischhusen, and our combined teams continue their efforts to explore the utility of AIM Biologicals for the treatment of NMOSD. In this abstract they will present, for the first time, some proof-of concept of AIM Biological in both in vitro and mouse models.”

Dr. Bruttel of the University, added, "These studies demonstrate that the AIM Biologicals induce human AQP4-specific regulatory T cells in vitro and prevent neuroinflammatory disease in animal models. We believe that Aquaporin-4-specific AIM Biologicals may be suitable for targeted immunosuppression in neuromyelitis optica spectrum disorders and are looking forward to continuing our work with our exclusive licensee, Aeterna, to advance this further.”

About Neuromyelitis Optica Spectrum Disorder (NMOSD)

NMOSD is an antibody mediated inflammatory central nervous system ("CNS") disorder that affects about one per million population per year. NMOSD, also known as Devic’s disease, is a chronic disorder of the brain and spinal cord dominated by inflammation of the optic nerve (optic neuritis) and of the spinal cord (myelitis). Typical symptoms include visual loss, muscle spasms, paraparesis, and incontinence. If left untreated, 50% of individuals with NMOSD will become wheelchair bound and blind, and 30% will have died within five years after the first attack. The water channel protein AQP4 is widely expressed in the brain, spinal cord, and optic nerves. Auto-antibodies directed against AQP4 play an important role in the pathogenesis of NMOSD.

Currently there are only three approved medications available for the treatment of NMOSD, all with very high annual treatment costs and the risk of the patient contracting serious infections. Therefore, the Company believes there remains a strong medical need to offer new therapeutic options to the patients.

In the U.S. and Europe there are currently approximately 10,000 to 15,000 patients living with NMOSD. Of these the AQP4 antibody seropositive patients who represent about 80% of the NMOSD population are the targeted patients for a potential therapy based on the AIM Biologicals technology. About AIM Biologicals

AIM Biologicals utilize a novel mechanism which is believed to demonstrate that peptide antigens presented on immunosuppressive MHC class I molecules can selectively and efficiently induce antigen-specific tolerance. Based on this mechanism, the targeted immunomodulating therapeutics are being designed as optimized soluble molecules with the goal that they may be adapted to selectively induce tolerance to various autoantigens. Pre-clinical studies conducted by the University thus far indicate that tolerance induction appears to be achieved via selective elimination of antigen-specific immune effector cells and via induction of antigen-specific regulatory T cells from naïve T cells. AIM Biologicals thus have the potential to become highly specific and effective yet not personalized treatments of NMOSD.

For the treatment of NMOSD, it is believed that the AIM Biologicals will present a specific antigen derived from the water channel protein aquaporin-4 (AQP4) loaded to soluble immunoregulatory HLA-G protein to selectively induce immunological tolerance in the central nervous system.

About Aeterna Zentaris Inc.

Aeterna Zentaris is a specialty biopharmaceutical company developing and commercializing a diversified portfolio of pharmaceutical and diagnostic products focused on areas of significant unmet medical need. The Company's lead product, macimorelin (Macrilen™; Ghryvelin®), is the first and only U.S. FDA and European Commission approved oral test indicated for the diagnosis of adult growth hormone deficiency (AGHD). The Company is leveraging the clinical success and compelling safety profile of macimorelin to develop it for the diagnosis of childhood-onset growth hormone deficiency (CGHD), an area of significant unmet need, in collaboration with Novo Nordisk.

Aeterna Zentaris is dedicated to the development of therapeutic assets and has recently taken steps to establish a growing pre-clinical pipeline to potentially address unmet medical needs across a number of indications, including neuromyelitis optica spectrum disorder (NMOSD), Parkinson's disease (PD), hypoparathyroidism and amyotrophic lateral sclerosis (ALS; Lou Gehrig's disease). Additionally, the Company is developing an oral prophylactic bacterial vaccine against SARS-CoV-2 (COVID-19) and Chlamydia trachomatis.

For more information, please visit www.zentaris.com and connect with the Company on Twitter, LinkedIn and Facebook.

Forward-Looking Statements

This press release contains statements that may constitute forward-looking statements within the meaning of U.S. and Canadian securities legislation and regulations and such statements are made pursuant to the safe-harbor provision of the U.S. Securities Litigation Reform Act of 1995. Forward-looking statements are frequently, but not always, identified by words such as “expects,” “anticipates,” “believes,” “intends,” “potential,” “possible,” and similar expressions. Such statements, based as they are on current expectations of management, inherently involve numerous risks, uncertainties and assumptions, known and unknown, many of which are beyond our control. Forward-looking statements in this press release include, but are not limited to, those relating to: expectations regarding conducting pre-clinical research to identify and characterize an AIM Biologicals-based development candidate for the treatment of NMOSD.

Forward-looking statements involve known and unknown risks and uncertainties, and other factors which may cause the actual results, performance or achievements stated herein to be materially different from any future results, performance or achievements expressed or implied by the forward-looking information. Such risks and uncertainties include, among others, results from ongoing or planned pre-clinical studies of our products under development may not be successful or may not support advancing the product to human clinical trials; our ability to raise capital and obtain financing to continue our currently planned operations; our now heavy dependence on the success of Macrilen™ (macimorelin) and related out-licensing arrangements and the continued availability of funds and resources to successfully commercialize the product, including our heavy reliance on the success of the license agreement and the amended license agreement (collectively the Novo Amended License Agreement); the global instability due to the global pandemic of COVID-19 and the war in the Ukraine and the resulting geopolitical instability, and its unknown potential effect on our planned operations; our ability to enter into out-licensing, development, manufacturing, marketing and distribution agreements with other pharmaceutical companies and keep such agreements in effect; and our ability to continue to list our common shares on the NASDAQ. Investors should consult our quarterly and annual filings with the Canadian and U.S. securities commissions for additional information on risks and uncertainties, including those risks discussed in our Annual Report on Form 20-F and annual information form, under the caption "Risk Factors". Given the uncertainties and risk factors, readers are cautioned not to place undue reliance on these forward-looking statements. We disclaim any obligation to update any such factors or to publicly announce any revisions to any of the forward-looking statements contained herein to reflect future results, events or developments, unless required to do so by a governmental authority or applicable law.

No securities regulatory authority has either approved or disapproved of the contents of this news release. The Toronto Stock Exchange accepts no responsibility for the adequacy or accuracy of this release.

Investor Contact:

Jenene ThomasJTC TeamT (US): +1 (833) 475-8247E: aezs@jtcir.com