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 for the potential treatment of Parkinson’s Disease (“PD”) were accepted for presentation at IMMUNOLOGY2022™, the Annual Event of the American Association of Immunologists, to be held May 6-10, 2022 in Portland, Oregon.

The abstract was selected for poster presentation and oral presentation at the congress, which will be given by Prof. Joerg Wischhusen, PhD, Head of the Laboratory of Experimental Tumor Immunology, Department of Obstetrics and Gynecology, School of Medicine, University of Wuerzburg (“the University”). Details of the abstract and presentations are as follows:

Title: α-synuclein peptides presented on chimeric MHC class Ib molecules prevent loss of substantia nigra neurons in an animal model for Parkinson’s disease1Number: P931Category: Therapeutic Approaches to Autoimmunity

Oral Presentation

Session Title:	Immune-Based Therapeutics for Neurological Disease
Date and time:	Friday, May 6, 2022, at 2:15 – 2:30 PM PT
Location:	Room B113-116, Oregon Convention Center (OCC), Portland, Oregon, USA

Poster Presentation

Session Title:	Therapeutic Approaches to Autoimmunity and Other Diseases
Date and time:	Saturday, May 7, 2022, at 2:30 – 3:45 PM PT
Location:	Exhibition Hall, Oregon Convention Center (OCC), Portland, Oregon, USA

“We are pleased that this abstract was accepted for presentation at IMMUNOLOGY2022, the largest annual immunology event worldwide,” commented Dr. Klaus Paulini, Chief Executive Officer of Aeterna Zentaris. “In collaboration with Aeterna, Prof. Wischhusen, Prof. Chi Wang Ip, and their teams at the University are advancing the in-vitro and in-vivo characterization of α-synuclein specific AIM Biologicals to explore the therapeutic potential in PD. We are encouraged by the data being presented from AAV-A53T-α-synuclein Parkinson’s disease mice, a new mouse model which replicates human PD with high validity.”

Prof. Joerg Wischhusen of the University, added, “My co-inventor Valentin Bruttel and I collaborated with the group of Prof. Ip at the Department of Neurology to show that treatment of PD mice with α-synuclein specific AIM Biologicals prevents the development of mobility impairments. Further, we were pleased to see the induction of antigen-specific regulatory T cells and rescue of dopaminergic neurons in the substantia nigra. We are very much looking forward to exploring the therapeutic potential of AIM Biologicals in this disease together with Aeterna’s team.”

The abstract is now available through the AAI Events conference app.

About Parkinson’s Disease (PD)

Parkinson’s disease is a neurodegenerative movement disorder affecting over 7 million people worldwide. PD belongs to a family of disorders termed synucleinopathies, which exhibit a characteristic deposition of α-synuclein aggregates in so-called Lewy bodies. Degeneration of dopaminergic neurons in the substantia nigra (SN) leads to a loss of dopaminergic transmission in the striatum. Neuroinflammation is a well-established hallmark of the disease. Recent data provide growing evidence for a strong autoimmune component in PD, with α-synuclein-specific T cell responses playing a key role in disease progression.

About AIM Biologicals

AIM Biologicals utilize a novel mechanism based on peptide antigens that are presented on immunosuppressive MHC class I molecules, to selectively and efficiently induce antigen-specific tolerance. Based on this mechanism, the targeted immunomodulating therapeutics are designed as optimized soluble molecules that are 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.

α-synuclein-specific AIM Biologicals may thus have the potential to become a highly specific and effective treatment of PD.

For the development of AIM Biologicals as potential PD therapeutics, Aeterna utilizes, among others, an innovative animal model on neurodegeneration by α-synuclein-specific T cells in AAV-A53T-α-synuclein Parkinson’s disease mice, which has recently been published by University of Wuerzburg researchers.

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 PD.

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

1 J. Wischhusen, J. Wu, F. Ahsan, R. McFleder, A. Karl, S. Mamatha Jayaram, H. Wecklein, A. Nienaber, D. Brünnert, V. Bruttel, and C. Wang Ip. 2022. α-synuclein peptides presented on chimeric MHC class Ib molecules prevent loss of substantia nigra neurons in an animal model for Parkinson’s disease. Presented at: IMMUNOLOGY2022™, Annual Meeting of The American Association of Immunologists, May 5 – 10, The American Association of Immunologists, Inc., Portland, Abstract 2150