T homas Struengmann, along with his identical twin brother Andreas, is a self-made German billionaire who built a massive fortune in the pharmaceutical industry. The brothers co-founded the generic drug company Hexal in 1986. They built Hexal into Germany's second-largest generic drug manufacturer, growing it into a major international player. They also owned a significant stake in the American generic drugmaker, Eon Labs.

In 2005, in a career-defining deal, the brothers sold both Hexal and their stake in Eon Labs to the Swiss pharmaceutical giant Novartis for approximately $7.5 billion. Since this massive exit, they have focused on managing their family's wealth through their private investment firm, Santo Holding. They have become major venture capital investors in the biotechnology and life sciences sectors. Their most notable and successful investment was their role as the seed investors and largest shareholders in BioNTech, the German biotech firm that, in partnership with Pfizer, developed one of the world's first and most effective mRNA vaccines for COVID-19.