EU/3/16/1725

On 29 August 2016, orphan designation (EU/3/16/1725) was granted by the European Commission to Akari Therapeutics Plc, United Kingdom, for recombinant protein derived from the saliva of the Ornithodoros moubata tick (also known as coversin or rEV576) for the treatment of paroxysmal nocturnal haemoglobinuria.

What is paroxysmal nocturnal haemoglobinuria?

Paroxysmal nocturnal haemoglobinuria (PNH) is a condition in which there is excessive breakdown of red blood cells, leading to the release into the urine of a large amount of haemoglobin (the pigment contained in the cells). Because of the red colour of haemoglobin, the passing of red urine, particularly in the mornings, is usually the most obvious sign of the disease. Patients may also experience problems related to blood clotting.

The condition is due to the lack of certain proteins on the surface of the red blood cells which normally protect them from being destroyed by the immune system (the body’s natural defences).

PNH is a long-term debilitating and life-threatening condition due to its complications including abdominal pain, infection and kidney problems, and problems due to bleeding and blood clots.

What is the estimated number of patients affected by the condition?

At the time of designation, PNH 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).

What treatments are available?

At the time of designation, the medicine Soliris (eculizumab) was authorised in the EU for the treatment of PNH. Bone marrow transplantation to replace the defective cells was another therapy available to patients, however this treatment is available to only a small proportion of patients since a suitable donor is required. Other methods such as blood transfusions and treatment to prevent clotting with blood-thinning compounds were used in some patients to improve symptoms.

The sponsor has provided sufficient information to show that the medicine might be of significant benefit for patients with PNH because initial studies suggest that it can be used in patients for whom Soliris does not work. This assumption will need to be confirmed at the time of marketing authorisation, in order to maintain the orphan status.

How is this medicine expected to work?

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. In patients with PNH, the complement proteins are overactive and cause damage to the patients’ own blood cells. By blocking the complement system, the medicine is expected to prevent complement proteins from damaging the blood cells, thereby helping to relieve the symptoms of the disease.

What is the stage of development of this medicine?

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 PNH was planned.

At the time of submission, the medicine was not authorised anywhere in the EU for PNH 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 13 July 2016 recommending the granting of this designation.

Opinions on orphan medicinal product designations are based on the following three criteria:

• 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.

The Committee for Orphan Medicinal Products reviews the orphan designation of a product if it is approved for marketing authorisation.