New oral test could replace painful insulin injections for hormone diagnosis

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: Suspected AGHD Subjects (Groups A, B, and C): * Age ≥ 18 years and ≤ 65 years, male or female. * Suspected AGHD, meeting at least one of the following criteria: * Congenital structural/gene defects in the hypothalamus or pituitary gland, or * History of surgery or radiotherapy in the hypothalamic or pituitary region, or * Adult traumatic brain injury (TBI) or central nervous system (CNS) infection, or * Confirmed deficiency of at least one pituitary hormone other than growth hormone (GH), or * Idiopathic childhood-onset GHD. * IGF-1 SDS \< 0. * Willing and able to comply with the study procedures and voluntarily sign the informed consent form. Matched Healthy Control Subjects (Group D): * Age ≥ 18 years and ≤ 65 years, male or female. * Matching criteria with Group A (subjects with highly suspected AGHD): 1. Sex; 2. Age; 3. BMI; 4. (If feasible) Estrogen use and administration route (oral, transdermal) in females: Exclusion Criteria: * Known or suspected hypersensitivity to growth hormone secretagogues (GHS) or their excipients or known allergy to insulin or its excipients. * Clinically significant conditions newly diagnosed within 6 months before screening, making the subject unsuitable for ITT: 1. Chronic congestive heart failure (New York Heart Association (NYHA) Class III or higher); 2. Other significant cardiovascular/cerebrovascular diseases, e.g., uncontrolled severe hypertension, severe arrhythmia, stroke or transient ischemic attack (TIA), or confirmed coronary artery disease; 3. Traumatic brain injury (TBI). * Short-acting GH therapy within 30 days before screening. * Long-acting GH therapy within 90 days before screening. * GH stimulation test performed within 7 days before the first dose. * Abnormal thyroid function during screening, or any adjustment to thyroid hormone replacement therapy dosage prior to the first study dose. * Abnormal gonadal function during screening, or any adjustment to testosterone/estrogen replacement therapy dosage prior to the first study dose. * Abnormal adrenal function during screening, or any adjustment to glucocorticoid replacement therapy dosage prior to the first study dose. * Type 1 diabetes diagnosed before screening, or uncontrolled Type 2 diabetes * Body mass index (BMI) ≥40.0 kg/m². * Major surgery (e.g., coronary bypass, hepatectomy/nephrectomy, gynecologic surgery) within 6 months before screening. * Acute neurological, digestive, respiratory, circulatory, endocrine, or hematologic diseases within 3 months before screening, judged by the investigator to potentially affect drug absorption, distribution, metabolism, excretion (ADME), or safety evaluation. * History or current diagnosis of malignancy (any type) before screening. * Electrocardiogram (ECG) findings during screening indicating QTc interval \>450 ms, or history of corrected QT interval (QTc) prolongation, or other clinically significant ECG abnormalities, or use of medications known to prolong QTc interval. * Sellar region MRI scan during screening showing untreated intracranial tumor growth. * History of clinically symptomatic psychiatric disorders persisting at screening. * History of Parkinson's disease or epilepsy persisting at screening. * Females with positive blood human chorionic gonadotropin (hCG) during screening, or lactating females, or females planning pregnancy from screening through follow-up completion. * Liver function abnormalities during screening * Use of medications directly affecting pituitary GH secretion or somatostatin-releasing drugs within a period \>5 half-lives before first study dose. * Use of strong cytochrome P450 family 3 subfamily A member 4/5 (CYP3A4/5) inhibitors or inducers. * Participation in any other drug or medical device clinical trial within 1 month prior to screening, or screening occurring within 5 half-lives of the investigational drug (whichever is longer). * Unwillingness to use protocol-specified contraception methods * Other conditions deemed by the investigator to make the subject unsuitable for participation in this clinical trial.