In the European Union (EU), Orphan Drug designation (“Orphan designation”) is granted to products intended to treat, prevent, or diagnose a life-threatening, chronic, or rare disease. These are defined as conditions affecting 5 in 10,000 people or less. Once a product receives this status, the drug developer also receives benefits such as fee reductions, protocol assistance, and market exclusivity. According to Korea BioMed, the European Medicines Agency (EMA) recently granted Orphan status to Hunterase ICV (intracerebroventricular) for the treatment of patients with severe mucopolysaccharidosis type II (MPS II/Hunter syndrome).
Hunterase ICV
So what exactly is Hunterase ICV? This enzyme replacement therapy (ERT) is delivered directly to cerebral ventricles. This overcomes difficulties in achieving targeted therapy by overcoming the blood-brain barrier. Researchers believe that Hunterase ICV can improve psychomotor development and reduce symptom burden. The Orphan Drug designation hinged on clinical data from a Japanese study. Within this study, researchers highlighted how the treatment lowered heparan sulfate by over 70%. Since heparan sulfate can cause nerve damage within the central nervous system, these reductions show promise for patients with MPS II.
New therapeutic options for patients are urgently needed. Thus, Hunterase ICV could potentially change the treatment field in the future.
Mucopolysaccharidosis Type II (MPS II / Hunter Syndrome)
Known as MPS II or Hunter syndrome, mucopolysaccharidosis type II is a rare, X-linked recessive genetic disorder. Because of this, most people affected are male, though in extremely rare cases, it can occur in females. In patients with MPS II, I2S deficiency causes the body to be unable to break down heparan sulfate and dermatan, types of complex sugar molecule chains. Instead, these molecules stay in the body, prompting worsening tissue and organ damage. Symptoms typically appear between ages 1.5-4 years, with the disease becoming fatal around ages 10-20. Symptoms and characteristics of MPS II include:
- Enlarged tongue, liver, and spleen
- Spinal stenosis
- Joint stiffness
- Developmental delays
- Microcephaly (overly large head)
- Hydrocephalus (excess fluid around the brain)
- Vision loss
- Skeletal irregularities
- Inguinal hernia
- Chronic diarrhea
- Abdominal distention
- Frequent respiratory infections
