PURPOSE 
The purpose of this study is to investigate a new form of treatment of Gaucher’s disease called "gene 
therapy". We will obtain blood cells from you which contain a small number of cells called "stem cells". 
These stem cells make all the different blood cells such as red blood cells, white blood cells and 
platelets. White blood cells are the cells of the blood which are most effective in fighting infections. 
Platelets are important to prevent potentially life-threatening bleeding. One type of the white cells 
made by the stem cells are called "macrophages". The macrophages of patients with Gaucher’s disease 
are the cells which store up the body lipid (a kind of fat) because they lack the GC enzyme. We will 
insert the normal gene for the missing GC enzyme into your stem cells. If we are successful, the stem 
cells which contain the GC gene will then produce blood cells which also contain the GC gene including 
macrophages. We expect that these new macrophages which contain the gene for the GC enzyme will 
then no longer accumulate lipid but that the GC enzyme now present in these cells will break down this 
fatty material. This should lead to improvement of problems typical for Gaucher’s disease like 
enlargement of liver and spleen as well as bone problems. There is no guarantee that this procedure 
will be successful. 
PROCEDURES 
Twenty days before infusion of your genetically altered blood cells, approximately 20 ml of marrow 
blood (4 teaspoons) will be drawn. These cells will be used to establish a layer of cells in culture flasks 
which will later feed your blood stem cells while the GC gene is inserted in them. Ten days after 
marrow aspiration, you will receive a catheter (small plastic tube) inserted in one of your large veins 
which makes it easier to collect your blood cells later. On the same day, you will also start receiving 
treatment with a growth factor (a substance which stimulates the growth of marrow and peripheral 
blood mother cells which can make red cells, white cells and platelets) called G-CSF. This factor will be 
given daily for four consecutive days. It will be injected underneath your skin. After four days, your 
peripheral blood cells contain an increased number of mother cells or stem cells. At this time, your 
blood cells will be collected on two consecutive days by connecting your catheter to a machine which 
separates white blood cells (leukopheresis). The stem cells are then purified from the white cells in the 
laboratory. Subsequently your blood cells will be treated in the laboratory for 5 days with a virus, which 
is engineered to carry the GC gene into your blood stem cells. Once the GC gene is in your stem cells, 
they will pass the GC gene on to all their daughter cells including the macrophages. The macrophages 
will then be able to break down the fatty material called lipid because they are now able to make the 
GC enzyme. The virus which carries the GC gene into your stem cells has been altered such that it 
cannot grow or spread in your body. 
After having inserted the GC gene into your blood cells, we will give your treated cells back into your 
body by infusing them into your vein through your catheter. The infusion will take place in the hospital 
where you will stay for one night, and you will be monitored closely for side effects during and after the 
infusion. Following the infusion you will be seen as an outpatient every month. We will obtain about 
30 ml of blood (6 teaspoons) and test your blood cells whether they contain the GC gene and whether 
the gene is producing GC enzyme. We will repeat the whole procedure of collecting your blood cells 
and transferring the GC gene into them two more times. 
Since this gene therapy procedure represents a new treatment for patients with Gaucher’s disease, it is 
important for us to observe you for at least five years so that we can evaluate the further course of your 
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