Castle Creek Biosciences is a late-clinical stage cell and gene therapy company focused on developing and commercializing disease-modifying and potentially curative therapies for rare genetic diseases.

With the acquisition of Novavita Thera (formerly a Cytotheryx company), Castle Creek will initially develop a gene therapy for hereditary tyrosinemia type 1 (HT1), a rare inborn error of metabolism caused by a lack of the enzyme fumarylacetoacetate hydrolase (FAH), which leads to the accumulation of tyrosine and its metabolites in the liver. HT1 affects approximately 1 in 100,000 live births and leads to cirrhosis, liver failure, and hepatocellular carcinoma. It is ultimately fatal if untreated. Liver transplantation is currently the only curative treatment for HT1.

Castle Creek will advance the development of LV-FAH, a potential therapy based on a lentiviral vector containing a functional copy of the human FAH gene. LV-FAH is administered directly to a patient through the portal vein. The therapy is designed to transduce hepatocytes and deliver the FAH enzyme that is deficient in these cells. Castle Creek plans to submit an investigational new drug (IND) application to the U.S. Food and Drug Administration for LV-FAH in HT1. In addition, Castle Creek said it continues to progress several additional candidates targeting other rare liver and metabolic diseases, as well as skin and connective tissue disorders.

In connection with the acquisition, Dr. Joseph Lillegard, PhD, has joined Castle Creek as chief scientific officer. Lillegard is a board-certified pediatric and adult general, thoracic, and fetal surgeon at the Children's Hospital of Minnesota. Lillegard led the cell and gene therapy research lab at Mayo Clinic that discovered LV-FAH. Robert A. Kaiser, PhD, has joined the company as vice president of preclinical development. Kaiser is a board-certified toxicologist with over a decade of experience designing, conducting, and reporting preclinical and IND-enabling studies.

Lillegard and Kaiser will be the company leads for Castle Creek's recently announced research collaboration with the Mayo Clinic to advance the discovery and development of investigational gene therapy candidates to treat osteogenesis imperfecta and classical Ehlers-Danlos syndrome.