Aeterna Zentaris Inc. provided an update on its therapeutic and diagnostic development pipeline programs and outlined upcoming key milestones. Autoimmunity Modifying Biologicals: Targeted, highly specific autoimmunity modifying fusion proteins for the potential treatment of neuromyelitis optica spectrum disorder ("NMOSD") and Parkinson's disease. AIM Biologicals represent a unique platform technology with the potential to address the cause and not only the symptoms of auto-immune and inflammatory, neurodegenerative disorders at early stages.

This approach is based on induction of selective and highly target-specific immune de-sensibilization based on the natural concept of feto-maternal tolerance. Recent Highlights: Demonstrated positive pre-clinical proof-of-concept in various in-vitro and in-vivo models. In-depth profiling of a limited set of candidates for potential use in clinical development.

Confirmed AIM Biologicals’ mechanism of action and efficacy in ex-vivo studies in human blood samples from both NMOSD and PD patients. Next Steps: Evaluation of manufacturing strategy and initiation of production of selected development candidates. Ongoing compilation of a comprehensive pre-clinical data package for scientific advice meetings with regulatory authorities, expected to take place in the near future.

Delayed Clearance Parathyroid Hormone ("DC-PTH", AEZS-150) Fusion Proteins: Potential treatment for chronic hypoparathyroidism: AEZS-150 is a fusion protein of PTH [1-34] coupled to a modified human growth-hormone binding protein (GHBP). Preclinical results so far indicate the potential for maintaining regular calcium and phosphate levels in blood longer and more consistently than with current treatments. This project aims to address this debilitating orphan disease, which is currently without satisfactory treatment options, with weekly instead of daily injections.

Recent Highlights: Detailed profiling of AEZS-150 through in-vitro studies and in-vivo models of hypoparathyroidism. Established a master cell bank for a cell line expressing AEZS-150 in good yield. Continued progress in the development of a production process suitable for larger scale GMP manufacturing.

Next Steps: Meet with regulatory authorities to determine the development path forward; Company expects such a meeting in Q4/2023, and as outcome, an abbreviated safety and toxicology program as the active principle ([1-34]-PTH fragment) is already approved and in use. Initiate IND-enabling preclinical studies in 2024. Macimorelin Therapeutic (AEZS-130):Ghrelin agonist in development for the treatment of ALS (Lou Gehrig's disease): Amyotrophic Lateral Sclerosis (ALS) is a debilitating and deadly orphan disease, and those who suffer from this terminal condition have few treatment options.

Macimorelin’s (AEZS-130) multiple modes of action should have the potential to improve the quality of life for these patients. Recent Highlights: Successful development of an alternative formulation suitable for use in ALS. Accumulating data for positive effects of AEZS-130 treatment on survival of motor-neurons.

Continued assessment of AEZS-130 in transgenic mouse ALS models and in human patient-derived neuron cultures. Completion of initial toxicology and safety studies to support clinical development as a therapeutic, in addition to the already existing body of safety and toxicology data from macimorelin diagnostic development. Next Steps: Following achievement of proof-of-concept, the Company will seek to have a scientific advice meeting with regulatory authorities to discuss program development next steps.

Completion of toxicology and safety studies to support treatment over prolonged periods. Diagnostics Development and Commercialization Update: Macimorelin Diagnostic: Approvedand commercialized as test for adult growth hormone deficiency and in clinical Phase 3 development for childhood-onset growth hormone deficiency ("CGHD") testing. Aeterna is currently conducting its pivotal Phase 3 safety and efficacy study AEZS-130-P02 (the “DETECT-trial”) evaluating macimorelin for the diagnosis of Childhood Onset Growth Hormone Deficiency (“CGHD”).

Most clinical sites in the U.S. as well as European countries are open for patient recruitment. Recent Highlights: Phase 3 Study: Significant progress made with DETECT patient recruitment also by engagement of an additional Clinical Research Organization (CRO). Currently three new countries (Armenia, Slovakia, and Turkey), have ongoing DETECT clinical trial application activities and almost half the foreseen subjects have meanwhile concluded the trial.

MacimorelinCommercialization: Having regained full rights to Macrilen® for the U.S. and Canada from Novo Nordisk in May 2023, the Company is actively focused on identifying an alternate development and commercialization partner for Macrilen® for U.S. and Canada.