Brett Hagen is Chief Accounting Officer and Senior Vice President of Finance at Mentari Therapeutics. He is a finance executive with more than 20 years of experience leading accounting and financial reporting, with a specialty in publicly traded biopharmaceutical companies.

Prior to joining Mentari, Brett served as Senior Vice President, Finance and Chief Accounting Officer of Kalaris Therapeutics, overseeing SEC reporting and compliance, treasury management, and all aspects of financial planning and analysis. Before Kalaris, Brett was Chief Accounting Officer of AlloVir, leading the company through its merger with Kalaris in March 2025. Earlier in his career, Brett held finance and accounting leadership roles at Eloxx Pharmaceuticals, Proteostasis Therapeutics, where he was Vice President, Finance and Controller, and BIND Therapeutics, where he served as Controller. Brett holds a BA from the University of Minnesota and graduate degrees in accounting from Wright State University and in finance from Suffolk University.