Patients with Fabry disease can suffer from nerve pain. It is assumed that the pain is caused by deposits of fatty substances in the nerve fibers. These deposits are caused by an enzyme deficiency (α-galactosidase A). Typically, the pain occurs in childhood and adolescence and disappears after a few years, probably due to the final destruction of the affected nerve fibers. Current pain therapy is inadequate, as patients often do not respond well to conventional painkillers.
- The investigational drug, Sativex®, is a drug approved in Switzerland for the treatment of spasticity in multiple sclerosis. We expect that pain conduction in the nerve cells will be altered after treatment with Sativex® and that the sensation of pain can be reduced. The dosage and method of use are in accordance with the recommendation of the Swiss Drug Compendium.
- For the duration of the study, the patient's previous pain therapy will be continued.
- The study will be conducted at the University Hospital Zurich and the Inselspital in Bern and is expected to last 18 months. A total of 22 patients will take part in the study.
The study is:
- Prospective, i.e. a study planned for the future in which a predetermined hypothesis is to be tested.
- Placebo-controlled = drug without active medical ingredient, placebo
- Randomized = The allocation of study participants to a treatment group is random; Sativex® or placebo.
- Double-blind = both you and the study doctor do not know which treatment is being used.
- Crossover = If you participate, you will be randomly divided into two groups: Group A receives the test drug first, while Group B receives the placebo. In the second phase of the study, group A now receives the placebo and group B the investigational drug.
- The probability that you will be treated with the investigational product is 100%. You will receive the investigational drug either in the first or second phase of the study. The allocation key can be viewed at any time in an emergency.
Aim of the study
In this publication, we refer to our research project as a study. If you take part in this study, you are a study participant.
Before an investigational substance/drug is used to treat a disease, it must be scientifically tested on study participants. We therefore want to investigate whether/how effective the investigational product/drug Sativex® is in Fabry disease. The investigational product/medication contains the active ingredients: tetrahydrocannabinol (THC) and cannabidiol (CBD), has been approved in Switzerland since 2013 and has the following properties: Sativex® is primarily used to treat moderate to severe spasticity in patients with multiple sclerosis. Sativex® is not yet approved for the treatment of chronic pain. We expect that taking Sativex® will reduce pain conduction in the nerves and the associated pain.
Who can take part?
Patients with Fabry disease who are over 18 years old and have had pain for three months.
Procedure
If you have decided to participate in the study, you will take part in a total of 9 visits. Visits 1-4-8 take place at the University Hospital Zurich and last two hours. Visits 2-3-5-6-7-9 take place at home and last half an hour. Here is a flow chart and a detailed tabular description of the visits:
Titration phase I and II (dose increase):
Within two weeks, the dose of the test drug/placebo is gradually increased from 0 to max. 12 sprays per day.
Treatment phase I and II:
The maximum dose of the test drug/placebo is administered for 4 weeks.
Washout phase I and II (dose reduction):
Within two weeks, the dose of the investigational drug/placebo is gradually reduced from max. 12 sprays/day reduced to 0.
Compensation
If you participate in this study, you will not receive any compensation.
Original study name
Effect of cannabinoids on pain in Fabry disease patients: A prospectie, randomized, double-blind, placebo-controlled, crossover, multicenter study
BASEC number
2021-00734
Sponsors
Swiss National Fund for the Promotion of Scientific Research