A Study of GSM-779690T in Healthy Adult Participants

Participants must meet all of the following inclusion criteria to be eligible for enrollment:

• Healthy and aged 18-55 years.
• Current Mini Mental State Examination (MMSE) score between 27 and 30 at screening.
• Able to provide their own written informed consent.
• Good general health with no disease expected to interfere with the study.
• Able to read, speak, and understand English to ensure compliance with cognitive testing and study visit procedures.
• Must be ambulatory and be willing to remain domiciled in the clinic for the required study procedures.
• Contraception requirements:

a. Women of childbearing potential (WOCBP) must agree to use a highly effective method of birth control (confirmed by the Investigator) from enrollment, throughout the study duration, and have a negative pregnancy test result at screening. Highly effective methods of birth control (those with a failure rate of < 1% per year when used consistently and correctly) include: (i) Combined (oestrogen- and progestogen-containing) hormonal contraception associated with inhibition of ovulation: oral, intravaginal, or transdermal, (ii) Progestogen-only hormonal contraception associated with inhibition of ovulation: oral, injectable, or implantable, (iii) Intrauterine device, (iv) Intrauterine hormone-releasing system, (v) Bilateral tubal occlusion, (vi) Tubal ligation, (vii) Sexual abstinence, i.e., refraining from heterosexual intercourse, or (viii) Vasectomized sexual partner (provided that partner is the sole sexual partner of the WOCBP study participant and that the vasectomized partner has received medical assessment of the surgical success).

b. Women not of childbearing potential are defined as women who are either permanently sterilized (hysterectomy, bilateral oophorectomy, or bilateral salpingectomy) or who are postmenopausal.

c. Males with childbearing partners must be willing to practice sexual abstinence or use double-barrier protection during study treatment and until 1 week after the last dose of study treatment.

Participants who meet any of the following criteria must not be included in the study:

• A history of any current or clinically significant gastrointestinal, renal, hepatic, bronchopulmonary, neurological, psychiatric, cardiovascular, endocrinological, ophthalmologic, hematological, or allergic disease or metabolic disorder.
• Use of any concomitant medications is prohibited, other than prescribed birth control methods stable 30 days prior to Day -1.
• A history of chronic use of non-steroidal anti-inflammatory drugs (NSAIDs) or procedures that require intravenous contrast within 72 hours of study initiation.
• A history of a psychiatric disorder such as schizophrenia, bipolar disorder or major depression according to the criteria of the most current version of the Diagnostic and Statistical Manual of Mental Disorders (DSM).
• Any evidence of current suicidal ideation or any previous suicide attempt as evaluated by the Columbia-Suicide Severity Rating Scale (C-SSRS).
• Diagnosis of a neurodegenerative disease or dementia, including but not limited to Alzheimer's disease (AD), Parkinson's disease, and Huntington's disease.