Marinus Pharmaceuticals, Inc. announced that on January 26, 2023, the Board appointed Steve Pfanstiel as Chief Operating Officer (COO") of the Company, effective immediately. Mr. Pfanstiel will retain his position as the Company's Chief Financial Officer and Treasurer. Mr. Pfanstiel, age 50, has served as the Company's Chief Financial Officer and Treasurer since April 2021.

Mr. Pfanstiel previously served as Vice President, Finance, of LifeScan, Inc. (LifeScan"), a diagnostic systems manufacturer with products focusing on the diabetes market, from January 2020 to March 2021, where he was responsible for supporting LifeScan's global commercial and development organizations, as well as its financial planning analysis function and treasury. Before LifeScan, Mr. Pfanstiel served as Senior Director of FP&A at OptiNose, Inc. (OptiNose"), a publicly traded specialty pharmaceutical company focused on creating and bringing to market innovative products for patients with diseases treated by ear, nose, and throat and allergy specialists, from February 2018 to January 2020. During his time at OptiNose, Mr. Pfanstiel served as finance leader for the supply chain, R&D and clinical organizations and was responsible for the broader strategic finance analysis across the organization.

From July 2016 to February 2018, Mr. Pfanstiel served as Senior Director supporting Global Strategic.