Aeterna Zentaris Inc., a specialty biopharmaceutical company, engages in developing and commercializing therapeutics and diagnostic tests in Canada, Switzerland, Ireland, Denmark, Germany, the United States, and internationally. Its lead product is Macrilen (macimorelin), an orally available peptidomimetic ghrelin receptor (GHSR-1a) agonist that stimulates the secretion of growth hormone by binding to the GHSR-1a for the diagnosis of patients with adult growth hormone deficiency and childhood-onset growth hormone deficiency, as well as endocrinology and oncology indications; AEZS-150, a delayed clearance parathyroid hormone fusion polypeptide that is in preclinical trial for the treatment of chronic hypoparathyroidism; and AEZS-130 that is in preclinical trial for the treatment of amyotrophic lateral sclerosis. The company also has a license and research agreement with University of Wuerzburg to development, manufacture, and commercialization of AIM biologicals for the treatment of neuromyelitis optica spectrum disorder; and for pre-clinical development towards the potential treatment of Parkinson's disease. In addition, it has a license agreement with Consilient Health Ltd. and NK MEDITECH Ltd. for the development and commercialization of macimorelin; a distribution and commercialization agreement with Er-Kim Pharmaceuticals Bulgaria Eood for the commercialization of macimorelin for the diagnosis of growth hormone deficiency in children and adults; as well as The University of Sheffield, the United Kingdom for the development, manufacture, and commercialization of parathyroid hormone fusion polypeptides for the treatment of chronic hypoparathyroidism. Aeterna Zentaris Inc. was incorporated in 1990 and is headquartered in Toronto, Canada.