Rett syndrome (RTT) is a genetic disease that is caused by abnormalities in a gene called MECP2 which is important for the normal functioning of nerve cells. It is a rare disease which almost always affects females. Females with RTT lose their ability to properly control their muscles, have feeding difficulties and learning disabilities. Other symptoms include difficulty breathing, irregular heartbeat, sleeping problems, constipation, repetitive hand movements and fits.
Sarizotan is an oral medicinal product that is being developed for the treatment of respiratory symptoms associated with Rett syndrome. Sarizotan works by binding to serotonin and dopamine receptors. By stimulating serotonin and dopamine receptors, sarizotan replaces the effect of some of the missing serotonin in the brain and spinal cord. This is expected to help restore normal breathing rhythm in patients with Rett syndrome. Currently, there is no cure for Rett syndrome and treatment focuses on managing the symptoms. If licensed, sarizotan could become the first therapy approved for treatment of Rett Syndrome patients.
Fenfluramine belongs to a class of drugs called the selective serotonin releasing agonists which stimulates multiple 5-HT receptor sub-types through the release of serotonin. Fenfluramine may also act on other receptors and these actions may help to reduce the frequency of seizures. When added to other standard anti-epileptic treatments, fenfluramine hydrochloride has shown preliminary evidence of reducing seizure frequency. If licensed, fenfluramine hydrochloride may offer an additional treatment option for patients with Lennox-Gastaut syndrome.