He also worked as a consultant on biotechnology for minister-president Gaston Geens of the Flemish government.
In 1985 he made the business plan and co-founded, together with Hugo Van Heuverswyn, the healthcare biotech company Innogenetics NV (Ghent, Belgium), of which he was General Manager until 1992, at which time he joined Genzyme.
He was Senior Vice President Corporate Affairs for Genzyme Europe and International, and a member of the European Management Committee of Genzyme Corporation until 2010, when he joined the Flemish Center for Medical Innovation (CMI).
Tambuyzer is a founding Board member and past Chairman of EuropaBio, the European Association for Bioindustries, and founder of the Ethics Working Group of this Association, as well as the Chair of the joint EBE/EFPIA-EuropaBio Orphan medicines Task Force.
He published on policies regarding orphan medicines and advanced therapies in Europe and internationally, on the European Clinical Trial Directive, and on the impact of biotechnology on healthcare systems.