Update on Positive Pre-Clinical Results from AIM Biologicals Development Program for the Potential Treatment of Parkinson’s Disease

– Data presented at IMMUNOLOGY2022^™, the Annual Event of the American Association of Immunologists

– Company advancing development of its Autoimmunity Modifying (“AIM”) Biologicals as a potential therapeutic treatment option for Parkinson’s Disease (“PD“)

TORONTO, ONTARIO, May 12, 2022 (GLOBE NEWSWIRE) — 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 provided an update on the positive results from pre-clinical studies of Aeterna’s Autoimmunity Modifying Biologicals (“AIM Biologicals”), for the potential treatment of Parkinson’s Disease (“PD”). As previously announced, the data were presented at IMMUNOLOGY2022^™, the annual event of the American Association of Immunologists, held on May 6-10, 2022 in Portland, Oregon.

“Under our collaboration with the University of Wuerzburg, Prof. Wischhusen, Prof. Chi Wang Ip, and their teams have provided data that we believe is important pre-clinical proof of concept for our AIM Biologicals platform,” said Dr. Klaus Paulini, Chief Executive Officer of Aeterna Zentaris. “In various in-vitro and in-vivo assays, the team has demonstrated the antigen-specific immune-modulatory activity of these HLA-G based molecules. We are very pleased with the encouraging progress of our AIM Biologicals program and the potential utility for the treatment of PD.”

AIM Biologicals are targeted, highly specific autoimmunity modifying therapeutics. The scientific concept behind this platform technology is “feto-maternal-tolerance”. During pregnancy, the immune system of mothers does not attack the fetus, which consists of 50% paternal proteins. For this, the immune system is not downregulated, but selectively de-sensibilized, thus ensuring that the mothers continue to be protected against infections.

For development as potential PD therapeutics, the Company is utilizing, 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 our University of Wuerzburg research collaborators.

The abstract titled “α-synuclein peptides presented on chimeric MHC class Ib molecules prevent loss of substantia nigra neurons in an animal model for Parkinson’s disease¹” outlining the data was presented by Prof. Joerg Wischhusen, PhD, Head of the Laboratory of Experimental Tumor Immunology, Department of Obstetrics and Gynecology, School of Medicine, University of Wuerzburg. As previously announced, that abstract was accepted as a poster presentation and was also selected for an oral presentation at IMMUNOLOGY2022^™.

The pre-clinical study investigated whether novel, antigen-specific, tolerance-inducing biomolecules that present peptide antigens on MHC class Ib-related molecules can inhibit neurodegeneration and prevent PD in-vivo.

The pre-clinical data presented showed consistent effects in various in-vitro and in-vivo models, verifying the potential of HLA-G based molecules to induce antigen-specific immune-modulation. Treatment with such molecules (AIM Biologicals) lead to apoptosis of antigen-specific cytotoxic T cells and to the stimulation of regulatory T cells. In a new, innovative mouse model of Parkinson’s disease, treatment with α-Synuclein specific AIM Biologicals showed a trend towards improved motoric function, as well as significant induction of regulatory T cells and rescue of substantia nigra neurons.

“There is a growing interest in the induction of antigen-specific immunotolerance in neuroinflammatory diseases,” said Prof. Joerg Wischhusen. “Utilizing such therapeutic approaches is of particular interest in the potential treatment of PD, since currently available treatment options are symptomatic and immunomodulatory treatments have not yet been tested. We were pleased with the results from this study and believe the translational potential of this approach deserves further exploration.”

The abstract and poster can be accessed on the Publications page of the Company’s website.

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 utilizes a novel mechanism based on peptide antigens that are presented on MHC class I molecules, to selectively and efficiently induce antigen-specific tolerance. Based on this mechanism, the immunomodulating therapeutics are designed as optimized soluble molecules that can be adapted to selectively induce tolerance to various autoantigens. Pre-clinical studies conducted by the University of Wuerzburg 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. Accordingly, α-Synuclein-specific AIM Biologicals may have the potential to become a highly specific and effective treatment of PD.

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 the potential of AIM Biologicals-based development candidate or related technology to be successful the treatment of PD and our expectations with respect to any further development of the AIM Biologicals.

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, including AIM Biologicals, may not be successful or may not support advancing the product to human clinical trials or to result in a successful product; 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 Thomas
JTC Team
T (US): +1 (833) 475-8247
E: 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