EU/3/16/1687: Orphan designation for the treatment of Guillain-Barré syndrome

Guillain-Barré syndrome is a condition of the nervous system that usually develops after a minor infection, such as a cold, in previously healthy individuals. It occurs when the antibodies produced by the immune system (the body's natural defence system) to target the infection turn against the nerve cells and attack them, leading to muscle weakness or paralysis. The weakness usually starts in the legs, then progresses over several days to affect the arms and facial muscles, leading to drooling, difficulty swallowing and breathing.

Guillain-Barré syndrome is a long-term debilitating and life-threatening condition due to breathing difficulties, nerve damage in arms and legs and organ dysfunction.

At the time of designation, Guillain-Barré syndrome affected approximately 0.2 in 10,000 people in the European Union (EU). This was equivalent to a total of around 10,000 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 513,700,000 (Eurostat 2016).

At the time of designation, the main treatments for Guillain-Barré syndrome were aimed at relieving the symptoms and reducing the duration of the disease. They consisted of immunoglobulins and plasma exchange, a procedure used to remove antibodies that are attacking the nerves by replacing the patient's plasma (the liquid part of the blood) with plasma from a donor.

The sponsor has provided sufficient information to show that this medicine might be of significant benefit for patients with Guillain-Barré syndrome, because early laboratory data show a reduction of symptoms with the medicine, which may improve recovery. This assumption will need to be confirmed at the time of marketing authorisation, in order to maintain the orphan status.

This medicine consists of a protein obtained from a blood-feeding tick, Ornithodoros moubata, which the tick uses to suppress the immune response of its host so as to go undetected. The protein works by blocking part of the immune system known as the complement system, which consists of a series of proteins that can enhance the actions of antibodies and immune cells. When given to patients with Guillain-Barré syndrome, the protein is expected to block the patient's complement system, thereby weakening the immune system and reducing the inflammation and nerve damage linked to attacks by immune cells.

The effects of the medicine have been evaluated in experimental models.

At the time of submission of the application for orphan designation, a clinical trial with the medicine in patients with Guillain-Barré syndrome was planned.

At the time of submission, the medicine was not authorised anywhere in the EU for Guillain-Barré syndrome or designated as an orphan medicinal product elsewhere for this condition.

In accordance with Regulation (EC) No 141/2000 of 16 December 1999, the COMP adopted a positive opinion on 19 May 2016 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.