A Phase 1 Study of BLKR201 in Healthy Adult Participants

The goal of this clinical trial is to learn if BLKR201 is safe in healthy adults. Researchers will also learn how the body absorbs and processes BLKR201 and how food may affect it. The main questions this study aims to answer are: * Is BLKR201 safe and well tolerated when taken as a single dose or for several days in a row? * How does BLKR201 move through and leave the body? * Does taking BLKR201 with food change how the body absorbs it? Researchers will compare BLKR201 to a placebo (a look-alike tablet that contains no drug) in most parts of the study to see how the drug affects participants. Participants will: * Take BLKR201 or a placebo by mouth * Stay at a clinical research unit for several days during dosing * Give blood and urine samples * Have heart tests, vital signs, and lab tests * Report any side effects In one part of the study, a small group of participants will receive BLKR201 only (no placebo). These participants will also have a sample of spinal fluid collected to measure how much BLKR201 reaches the fluid around the brain and spinal cord.