De Sousa is a Medical Doctor by training, having earned his medical degree at the University of Lisbon. He holds an Executive MBA from the Stern School of Business, New York University. Before he joined Zealand Pharma, de Sousa was Chief Business Officer at BBB Therapeutics. He also served as VP International at Takeda Pharmaceuticals, VP Corporate Licensing at Nycomed and Chief Business Officer at Newron Pharmaceuticals.