GNT0003 is a gene therapy medication delivered through a single intravenous injection. It uses a modified virus (adeno-associated viral vector) to deliver a working copy of the UGT1A1 gene into the body. This therapy aims to help patients with severe Crigler-Najjar syndrome who need daily phototherapy treatments.

Imlifidase is a medication given before the gene therapy to prepare the body for treatment. It helps reduce antibodies that might interfere with the gene therapy, specifically in patients who have existing antibodies against the viral vector (AAV8) used in the treatment.

Crigler-Najjar Syndrome – A rare genetic disorder that affects the liver’s ability to process bilirubin, a yellow substance produced when red blood cells break down. The condition is characterized by high levels of bilirubin in the blood, which can cause yellowing of the skin and eyes (jaundice). People with this syndrome are born with a defect in the gene that produces the enzyme responsible for converting bilirubin into a form that can be removed from the body. The syndrome exists in two forms, with type I being more severe and present from birth. The condition is inherited in an autosomal recessive pattern, meaning both parents must pass on the defective gene for a child to develop the syndrome.