Fragile X syndrome is the most common inherited cause of intellectual disability and the most common known cause of autism. Fragile X syndrome is due to a gene mutation on the X chromosome that impacts the FMRP protein, which is responsible for regulating the synapses of nerve cells. The full mutation causes Fragile X syndrome. It is estimated that one in 4,000 males and one in 6,000 females have the full mutation. Generally, males are more severely affected, with approximately 50% of the females having some features of the syndrome. Clinically, Fragile X syndrome is characterized by intellectual handicap, hyperactivity and attentional problems, autistic symptoms, anxiety, emotional lability and epilepsy. Currently, there are no medicines approved for the treatment of Fragile X syndrome.
Neuren conducted a Phase 2 double-blind placebo-controlled clinical trial in subjects aged 12 to 45 years with Rett syndrome, in which treatment with trofinetide showed clinical improvement in many of the core symptoms of Fragile X syndrome.
The FDA and the European Medicines Agency (EMA) have both granted Orphan Drug designation to Neuren for trofinetide in Rett syndrome. The FDA has also granted Fast Track designation.