• The study compound is being developed for the treatment of Alzheimer's disease. Alzheimer's disease is a brain disorder that slowly causes memory loss, confusion, and changes in behavior.
• In this clinical trial, we are investigating how the study compound is processed and eliminated by the body and how well it is tolerated when it is used by healthy participants.
• The study compound or placebo will be administered as a tablet (by mouth). A placebo is a compound without an active ingredient.
• The trial consists out of several parts. In part C you receive the study compound or placebo once daily for 10 days.
• In all parts: cerebrospinal fluid will be collected from you at 2 different times during the stay through a lumbar puncture. This involves inserting a thin needle between two vertebrae in the lower back. This procedure is not entirely without risk. Collecting this fluid is important because it provides an indication of the amount of the study compound in the brain and its possible effects after each dose of the study compound. The lumbar puncture will be performed by an experienced specialist. The specialist will use numbing medication to minimize any pain or discomfort from the needle.

All (possible) medicines can cause side effects. Because the compound has not yet been administered to humans, there are currently no known side effects in humans. In rare cases (<0.1%), serious side effects can occur during the first administration of new compounds to humans. The compound has already been extensively tested in the laboratory and on animals. Prior to the medical screening, you will receive written information about the trial, which also describes the possible side effects based on these animal tests. 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. 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 60 and no more than 75 years old.
• Your Body Mass Index (BMI) is at least 18.0 and at most 32.0 kg/m². 
• Both non-smokers and light smokers (maximum of 5 cigarettes per day) are allowed to participate in this clinical trial. 24 hours before entry to the research facility and during your stay in our research facility you are not allowed to smoke.
   
• As a female you can only participate if you meet one of the following conditions:
  • You have passed the menopause (no periods for at least 12 months);
  • You have been sterilized.
• As a male you can only participate if you meet one of the following conditions:
  • You are using a condom in combination with an additional contraception method used by your female partner;
  • You have been sterilized or your female partner is 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 of the previous study). For some study compounds this can be 90 days. This will be discussed during your telephone screening.
• 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 C: The trial consists of 1 period during which you will stay in the research facility in Groningen for 18 days (17 nights). The follow-up visit will take place 6 to 10 days after your departure from the research facility.

Note: You must be available for all dates to be able to participate in this clinical trial. The location in Groningen is Van Swietenlaan 6.