• The trial consists of 2 parts. You can only participate in one part.
• The new compound may potentially be used for the treatment of multiple sclerosis. Multiple sclerosis is a long-term disease that currently has no cure. Multiple sclerosis damages the protective layer around nerve cells (called myelin) in the brain and spinal cord. The nerve damage is caused by inflammation. Damage to nerves can cause numbness, weakness, difficulty walking, and vision changes, among other things. Only a few medications are available and able to slow down the worsening of the disease. The aim of this study is to see how certain compounds that are already on the market can influence each other when they are used together with the new compound.
• In part A, you will receive the study compound as tablet by mouth and the approved compound as capsules by mouth.
• In part B, you will receive the study compound and the approved compound as tablets via the mouth.

The active ingredient in the study compound has been administered to about 2700 healthy people and patients. The patients had diseases including multiple sclerosis, liver disease, inflammatory bowel disease, or COVID‑19. The compound has also been studied extensively in the laboratory and in animals. Treatment with the new compound may cause side effects or discomforts. The most frequently reported side effect in healthy people who received the compound was a headache. Other potential risks include effects on liver function, which may lead to yellowing of the skin. You may also experience other, yet unknown, side effects. Prior to the medical screening, you will receive written information about the trial, which also describes the possible side effects. This information will also be discussed with you at the start of the medical screening. You can then ask questions to the screening physician or nurse. Once everything is clear to you, you can decide to give written consent to participate in the trial. The medical screening will only take place after you have given written consent to participate in the trial. We want to emphasize that even after giving written consent, participation in any clinical trial is voluntary. You can decide at any time not to participate or to stop the medical screening or the trial. You do not need to provide a reason for why you no longer wish to participate.

• You are a healthy male or female.
• You are at least 18 and at most 65 years old.
• Your weight is at least 50 kg and your Body Mass Index (BMI) is at least 18.0 and at most 30.0 kg/m2. 
• You do not smoke (you have not smoked in the 60 days before the start of the trial) and you do not use any products that contain nicotine.

• As a female you can only participate if you are not pregnant, not breast feeding and meet one of the following conditions:
  • You have been using hormonal contraception for at least 1 month prior to the start of the trial (for example the contraceptive pill or an intra-uterine device containing hormones) in combination with a condom;
  • You use a copper intra-uterine device in combination with a condom;
  • You have passed the menopause (no periods for at least 12 months);
  • You have been sterilized or your male partner has been sterilized;
  • You are not sexually active according to your lifestyle;
  • You are only sexually active with a partner of the same sex.
• As a male you can only participate if you meet one of the following conditions:
  • You are using a condom during intercourse with your fertile female partner;
  • You have been sterilized or your female partner has been sterilized or has passed the menopause (no periods for at least 12 months);
  • You are not sexually active according to your lifestyle;
  • You are only sexually active with a partner of the same sex.

Note:

• You cannot participate in the trial if you have participated in another clinical trial in the 30 days prior to the first compound administration in this clinical trial (counting from the follow-up visit). This may be longer for certain trials, so please contact us for more information.
• To determine if you are suitable to participate in this trial, you will undergo a medical screening. Depending on availability, this can be performed in Groningen or in Utrecht.

Part A: the trial consists of 1 period during which you will stay in the research facility in Groningen (location van Swietenlaan 6) for 17 days (16 nights). The follow-up is by telephone and will take place 5 – 9 days after your departure from the research facility.

Part B: the trial consists of 2 periods in which you will stay in the research facility in Groningen (location van Swietenlaan 6) for 7 days (6 nights) in the first period and 6 days (5 nights) in the second period. Between the periods, you will take the study compound at home, and you will return to the research facility once for a short visit. The follow-up is by telephone and will take place 5 – 9 days after your departure from the research facility after the second period.

Note: You must be available for all dates to be able to participate in this clinical trial.