Mr. Mullennix is the Chief Financial Officer leading the Finance, Accounting, and Investor Relations activities at Plexium.

Stephen joined Plexium in 2022 to lead the Finance, Accounting, Investor Relations and other corporate functions at Plexium. He brings deep expertise in capital markets, operational finance, and executive leadership roles. Stephen joined Plexium from ProSciento, Inc., a leading Clinical Research Organization in the metabolic disease arena, where he served as CFO. Prior to ProSciento, Mr. Mullennix was CFO and COO of UroGen Pharma, Ltd (NYSE:URGN), a uro-oncology drug developer. During his tenure at UroGen, he led finance functions as the CFO, and then transitioned to COO as the company successfully launched JELMYTO, its first FDA-approved drug for urothelial cancer. Before UroGen, Mr. Mullennix was Chief Financial Officer and Senior Vice President of Operations at SolarReserve, LLC, and Managing Director at US Renewables Group, a private equity investment fund with more than $750 million of assets under management. He has been directly involved in $3.3 billion of public, private, equity, debt and M&A transactions.

Stephen earned his MBA with High Honors from the Anderson School at University of California Los Angeles, and BA in Economic Geography from Dartmouth College where he graduated Phi Beta Kappa and Summa Cum Laude.