Aeterna Zentaris Inc. operates as a specialized biopharmaceutical company, dedicated to the creation and market introduction of both therapeutic drugs and diagnostic tests. Its flagship product, macimorelin, is an orally administered peptidomimetic ghrelin receptor (GHSR-1a) agonist. This compound functions by binding to the GHSR-1a, thereby stimulating the secretion of growth hormone. Macimorelin is employed for diagnosing growth hormone deficiency in both adult and pediatric patients, and is also under investigation for various oncology indications. The drug is marketed commercially under the brand name Macrilen. The company engages in various licensing agreements, prominently with University Wuerzburg. This collaboration encompasses the research, development, manufacture, and commercialization of a prospective COVID-19 vaccine. It also involves developing, producing, and marketing a treatment for neuromyelitis optica spectrum disorder (NMOSD), establishing human 3D intestinal tissue models for infection biology research, and advancing pre-clinical work towards a potential Parkinson's disease therapy. Additionally, Aeterna Zentaris has formed licensing partnerships with Consilient Health Ltd., Novo Nordisk Health Care AG, and NK MEDITECH Ltd. for the development and commercialization of macimorelin in the United States and Canada. Another key collaboration is with The University of Sheffield in the United Kingdom, dedicated to the research, development, manufacturing, and commercialization of parathyroid hormone fusion polypeptides designed to treat primary hypoparathyroidism. Founded in 1990, Aeterna Zentaris Inc. maintains its corporate headquarters in Summerville, South Carolina.