EU/3/04/214: Orphan designation for the treatment of acute myeloid leukaemia

Acute myeloid leukaemia is a disease in which cancer cells are found in the blood and the bone marrow. The bone marrow is the spongy tissue inside the large bones in the body. Normally, the bone marrow makes cells called “blasts” that mature into several different types of blood cells that have specific functions in the body. These include red cells, white cells and platelets. Red blood cells carry oxygen and other materials to all tissues of the body. White blood cells fight infection. Platelets make the blood clot. When leukaemia develops, the bone marrow produces large numbers of abnormal blood cells. There are several types of leukaemias. In myeloid leukaemia blasts that are developing into white blood cells called granulocytes are affected. The blasts do not mature and become too many. These blast cells are then found in the blood and also accumulate in the bone marrow. Leukaemia can be acute (when it develops quickly with many blasts). Acute myeloid leukaemia is life-threatening.

At the time of designation, acute myeloid leukaemia affected approximately 0.7 in 10,000 people in the European Union (EU). This was equivalent to a total of around 32,000 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 25), Norway, Iceland and Liechtenstein.
At the time of designation, this represented a population of 464,200,000 (Eurostat 2004).

Treatment for leukaemia is complex and depends on a number of factors including the type of leukaemia, the extent of the disease and whether the leukaemia has been treated before. It also depends on the age, the symptoms, and the general health of the patient. The primary treatment of acute myeloid leukaemia is chemotherapy (using drugs to kill cancer cells). Several products were authorised for the condition in the Community at the time of submission of the application for orphan drug designation. Midostaurin might be of potential significant benefit for the treatment of acute myeloid leukaemia, because it may act in a different way than other medicines and it might add to the effect of the current standard treatment. The assumption will have to be confirmed at the time of marketing authorisation. This will be necessary to maintain the orphan status.

Enzymes are proteins produced by the human body that speed up the conversion of certain substances into other substances. Midostaurin inhibits an enzyme, the so-called fms-like tyrosine kinase 3 (FLT3). It has been found that this enzyme plays an important role in the survival and self-renewal of the blast cells, but not anymore after the maturation of these cells. FLT3 has been identified in >80% of the myeloid leukaemia blast cells. Midostaurin might, by inhibition of this FLT3 enzyme activity, help in slowing down or stopping the further growth of the leukaemia cells and might help in the destruction of these cells carrying FLT3.

The effects of midostaurin were evaluated in experimental models. At the time of submission of the application for orphan designation, clinical trials in patients with acute myeloid leukaemia were ongoing.

Midostaurin was not marketed anywhere worldwide for acute myeloid leukaemia or designated as orphan medicinal product elsewhere for this condition, at the time of submission.

In accordance with Regulation (EC) No 141/2000 of 16 December 1999, the COMP adopted a positive opinion on 16 June 2004 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.