EU/3/10/804

On 26 November 2010, orphan designation (EU/3/10/804) was granted by the European Commission to Dr Hans Moebius, United Kingdom, for methylthioninium for the treatment of progressive supranuclear palsy.

The sponsorship was transferred to Prof. Claude Wischik, United Kingdom, in February 2012.

For a list of the administrative updates to this public summary of opinion, please refer to the PDF document below.

What is progressive supranuclear palsy?

Progressive supranuclear palsy (PSP), which is also known as Steele-Richardson-Olszewski syndrome, is a rare disease that involves the gradual deterioration of parts of the brain. Symptoms include loss of balance with unexplained falls, stiffness, difficulty moving the eyes, particularly up and down, personality changes and dementia (loss of intellectual function). The disease usually starts in people aged over 40 years and gradually gets worse over a number of years.

Patients with PSP have abnormal tangles of a protein called ‘tau’ in their brain, which are thought to cause the gradual deterioration of brain tissue seen in these patients.

PSP is a debilitating and life-threatening disease that leads to a progressive inability to move and poor prospects of long-term survival.

What is the estimated number of patients affected by progressive supranuclear palsy?

At the time of designation, PSP affected approximately 0.6 in 10,000 people in the European Union (EU). This was equivalent to a total of around 30,000 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 the knowledge of the Committee for Orphan Medicinal Products (COMP).

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*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 506,300,000 (Eurostat 2010).

What treatments are available?

At the time of designation, no satisfactory methods were authorised in the EU for the treatment of PSP. Because of their tendency to fall, patients were often offered walking aids, as well as special glasses to help them to look down. Physiotherapy was used to keep the joints flexible. Medicines developed to treat Parkinson’s disease were used in some PSP patients, but their effect was usually temporary.

How is this medicine expected to work?

Methylthioninium is expected to work by dissolving the abnormal tangles of tau proteins in the brain of patients who have progressive supranuclear palsy, thereby slowing down or reversing the symptoms of the disease.

What is the stage of development of this medicine?

The effects of methylthioninium have been evaluated in experimental models.

At the time of submission of the application for orphan designation, no clinical trials with methylthioninium in patients with PSP had been started.

At the time of submission, methylthioninium was used or authorised in several countries for the treatment of other diseases including urinary-tract infection, drug-induced methaemoglobinaemia, ifosfamide encephalopathy and refractory shock syndromes.

At the time of submission, methylthioninium was not authorised anywhere in the EU for PSP 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 9 September 2010 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 European Union) 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.