EU/3/09/674

Scarring post glaucoma filtration surgery is the formation of excessive scar tissue following an operation to treat glaucoma. Glaucoma is a disease where the pressure in the eye rises because of an accumulation of fluid inside the eye that cannot drain away. This affects the optic nerve (the nerve that sends signals from the eye to the brain) and can cause loss of vision.

In the operation called 'filtration surgery', a small channel is created through the sclera (the white of the eye) to allow accumulated fluid to drain away. Scarring may occur after surgery when, during healing, too much collagen (a type of protein) is deposited in the channel. This causes the channel to seal up and the pressure inside the eye to build up again.

Scarring post glaucoma filtration surgery is a serious and long-term debilitating condition because it may lead to loss of vision.

At the time of designation, the number of patients at risk of scarring post glaucoma filtration surgery was estimated to be approximately 1.4 people in 10,000 in the European Union (EU). This was equivalent to a total of around 71,000 people*, and is below the threshold for orphan designation, which is 5 people in 10,000. This is based on the information provided by the sponsor and 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 27), Norway, Iceland and Liechtenstein.
At the time of designation, this represented a population of 504,800,000 (Eurostat 2009).

At the time of designation, no satisfactory methods were authorised in the EU for the prevention of scarring post glaucoma filtration surgery. Medicines that stop the growth of cells (and are often also used to treat cancer) can be injected at the incision site to slow down the formation of scar tissue and prevent the channel sealing up.

Recombinant human serum amyloid P is expected to work in the same way as the naturally-occurring substance human serum amyloid P, which circulates in the blood and is involved in wound healing. This medicine is expected to help the wound in the eye to heal by helping to remove damaged tissue and blocking the production of excess collagen at site of injury, thereby avoiding excessive scarring.

Recombinant human serum amyloid P is to be given by injection into the eyes of patients undergoing glaucoma filtration surgery.

Recombinant human serum amyloid P is made by a method known as 'recombinant DNA technology': it is made by a cell that has received the human gene (DNA) that makes it able to produce human serum amyloid P.

The effects of recombinant human serum amyloid P have been evaluated in experimental models.

At the time of submission of the application for orphan designation, no clinical trials in patients with scarring post glaucoma filtration surgery had been started.

At the time of submission, recombinant human serum amyloid P was not authorised anywhere in the EU for the prevention of scarring post glaucoma filtration surgery 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 8 July 2009 recommending the granting of this designation.

• the seriousness of the condition;
• the existence of alternative methods of diagnosis, prevention or treatment;
• and either the rarity of the condition (affecting not more than 5 in 10,000 people in the Community) or the 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 the quality, safety and efficacy is necessary before a product can be granted a marketing authorisation.