Busilvex is a concentrate to be made up into a solution for infusion (drip into a vein). It contains the active substance busulfan.
|Table of Contents|
|What is it used for?|
|How is it used?|
|How does it work?|
|How has it been studied?|
|What benefits has it shown during the studies?|
|What is the risk associated?|
|Why has it been approved?|
Busilvex is used in adults and children as a ?conditioning? (preparative) treatment before transplantation of haematopoietic progenitor cells (the cells that make blood cells). This type of transplant is used in patients who need to replace their blood-making cells, because they have a blood disorder (such as a rare type of anaemia) or a cancer of the blood. Busilvex treatment is followed by treatment with another medicine (cyclophosphamide in adults, and cyclophosphamide or melphalan in children).
Because of the number of patients in the European Union (EU) that undergo this type of conditioning and transplant is low, busulfan was designated as an ?orphan medicine? (a medicine used in rare diseases) on 29 December 2000.
The medicine can only be obtained with a prescription.
Busilvex should be used by a doctor who has experience in treatments given before transplantation. The recommended dose of Busilvex in adults is 0.8 mg per kilogram body weight. In children up to 17 years of age, the recommended dose of Busilvex is based on the weight of the child and varies between 0.8 and 1.2 mg/kg. Busilvex is given as a central intravenous infusion (drip into a central vein in the chest). Each infusion lasts for two hours and it is given to the patient every six hours on four consecutive days before treatment with cyclophosphamide or melphalan and the transplant. Before receiving Busilvex, patients are given anticonvulsive medicines (to prevent seizures) and anti-emetic medicines (to prevent vomiting).
The active substance in Busilvex, busulfan, belongs to a group of medicines called ?alkylating agents?. These substances are ?cytotoxic?. This means that they kill cells, especially cells that develop rapidly, such as cancer or progenitor (or ?stem?) cells (cells that make other types of cell). Busulfan is used before transplantation to destroy abnormal cells and the patient?s existing haematopoietic progenitor cells. This is called ?myeloablation?. Cyclophosphamide or melphalan is then used to suppress the immune system, so that the body?s natural defences are decreased. This helps the transplanted cells to ?engraft? (when they start to grow and produce normal blood cells).
The effects of Busilvex were first tested in experimental models before being studied in humans. The applicant also presented data from the scientific literature.
Busilvex has been studied in patients, mainly with blood cancer, who needed transplantation of haematopoietic progenitor cells. There were two main studies involving 103 adults and one involving 55 children. The main measures of effectiveness were the number of patients with myeloablation (with reduced counts of white blood cells and platelets) and ?engraftment? (the time for the white blood cells to return to higher levels).
All adults and children achieved myeloablation. On average, engraftment was reached in 10 days in adults and 11 days in children with ?autotransplantation? (when the patient receives their own cells, harvested and stored before the transplant). Engraftment was obtained in 13 days in adults and 21 days in children with ?allotransplantation? (when the patient receives cells from a donor).
Apart from the decrease in blood cell counts, which this is the intended effect of the medicine, the most serious side effects of Busilvex are infection, liver disorders including blocking of a liver vein, graft versus host disease (when the transplanted cells attack the body) and respiratory (lung) disorders. For the full list of all side effects reported with Busilvex, see the Package Leaflet.
Busilvex should not be used in people who may be hypersensitive (allergic) to busulfan or any of the other ingredients. It must not be used in women who are pregnant. Breast-feeding should be stopped when treatment with Busilvex is started. Busilvex can affect fertility in both sexes. Because of this, female patients should not become pregnant during treatment and for up to six months afterwards, and male patients are advised not to father a child during and for up to six months after treatment with Busilvex.
Caution is needed when Busilvex is used at the same time as other medicines, such as itraconazole (used to treat some infections), ketobemidone (used to treat pain) and paracetamol. See the Package Leaflet for full details.
The Committee for Medicinal Products for Human Use (CHMP) concluded that the effectiveness of Busilvex had been shown, and that it provides an alternative to busulfan tablets, which have disadvantages such as the large number of tablets that need to be taken. The Committee decided that Busilvex?s benefits are greater than its risks as conditioning treatment prior to haematopoietic progenitor cell transplantation. The Committee recommended that Busilvex be given marketing authorisation.