EU/3/17/1856: Orphan designation for the treatment of neuromyelitis optica spectrum disorders

Neuromyelitis optica spectrum disorders are inflammatory disorders that mainly affect the optic (eye) nerve and the spinal cord. They can lead to reduction or loss of vision, loss of sensation, loss of bladder control, weakness and paralysis of the arms and legs.

The disorders occur more frequently in women than in men. They are thought to be caused by the immune system (the body's natural defences) mistakenly producing antibodies that attack the nerve cells.

Neuromyelitis optica spectrum disorders are debilitating and life threatening due to damage to the nervous system function.

At the time of designation, neuromyelitis optica spectrum disorders affected approximately 0.4 in 10,000 people in the European Union (EU). This was equivalent to a total of around 21,000 people*, and is below the ceiling for orphan designation, which is 5 people in 10,000. This is based on the information provided by the sponsor and the knowledge of the Committee for Orphan Medicinal Products (COMP).

*Disclaimer: For the purpose of the designation, the number of patients affected by the condition is estimated and assessed on the basis of data from the European Union (EU 28), Norway, Iceland and Liechtenstein. This represents a population of 515,700,000 (Eurostat 2017).

At the time of designation, no satisfactory methods were authorised in the EU for the treatment of neuromyelitis optica spectrum disorders. Treatments were aimed at reducing inflammation. They included medicines such as corticosteroids and immunosuppressants, as well as plasmapheresis (also called plasma exchange, a procedure to remove antibodies from the liquid part of the blood).

Inebilizumab is a monoclonal antibody (a type of protein) that attaches to a type of immune cell called CD19+ B cells and causes their death. CD19+ B cells produce antibodies responsible for attacking the nerves in neuromyelitis optica spectrum disorders. By reducing the numbers of B cells, the medicine is expected to prevent damage to nerve cells and reduce the symptoms of the condition.

The effects of inebilizumab have been evaluated in experimental models.

At the time of submission of the application for orphan designation, clinical trials with inebilizumab in patients with neuromyelitis optica spectrum disorders were ongoing.

At the time of submission, inebilizumab was not authorised anywhere in the EU for neuromyelitis optica spectrum disorders. Orphan designation of inebilizumab had been granted in the United States for this condition.

In accordance with Regulation (EC) No 141/2000 of 16 December 1999, the COMP adopted a positive opinion on 16 February 2017 recommending the granting of this designation.

• the seriousness of the condition;
• the existence of alternative methods of diagnosis, prevention or treatment;
• either the rarity of the condition (affecting not more than 5 in 10,000 people in the EU) or insufficient returns on investment.

Designated orphan medicinal products are products that are still under investigation and are considered for orphan designation on the basis of potential activity. An orphan designation is not a marketing authorisation. As a consequence, demonstration of quality, safety and efficacy is necessary before a product can be granted a marketing authorisation.