The Food and Drug Administration has stopped a gene therapy study for Hunter syndrome after imaging turned up small nodules or fluid-filled masses in the spines of five children who received the treatment years ago.
REGENXBIO disclosed the clinical hold on its Hunter syndrome therapy on August 24, 2026. The therapy, RGX-121, is an investigational one-time treatment for the rare inherited disorder also known as mucopolysaccharidosis type II. The company said it no longer expects to resubmit its application for approval in the near term.
