Aventis Transkaryotic Therapies

Transkaryotic Therapies (TKT) was a biopharmaceutical company focused on developing treatments for rare genetic diseases using its proprietary gene activation technology. The company is best known for developing Replagal (agalsidase alfa) for Fabry disease and Elaprase (idursulfase) for Hunter syndrome. TKT maintained a significant partnership with Aventis for the development of Dynepo, a gene-activated erythropoietin for the treatment of anemia. The company was acquired by Shire in 2005 for approximately $1.6 billion, forming the foundation of Shire's Human Genetic Therapies (HGT) division. This business unit eventually became a cornerstone of the global rare disease market before Shire's acquisition by Takeda.