Phase 1 Trial to Evaluate the Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of TRT-448 in Healthy Adult Subjects

Inclusion Criteria: * Medically healthy , as determined by pre-study medical history, and without clinically significant abnormalities * Adult males and females, 18 to 55 years of age (inclusive) at screening * Body mass index (BMI) between 18 and 32 kg/m2 (inclusive) with body weight: ≥ 70 kg for the SAD 1 cohort; ≥ 50 kg for all other cohorts * Willing and able to comply with all study assessments and adhere to the protocol schedule and restrictions Exclusion Criteria: * History of anaphylaxis or other significant allergy which would interfere with the volunteer's ability to participate in the study, including severe Types I-IV hypersensitivity reactions, cytokine release syndrome, or allergic reactions to multiple drugs * History or presence of cardiovascular, pulmonary, hepatic, renal, hematological, gastrointestinal cholecystectomy, irritable bowel syndrome, inflammatory bowel disease, etc.), esophageal, endocrine, immunologic, autoimmune and/or inflammatory disease, dermatologic, psychiatric, or neurological disease/disorder * History of surgery or hospitalization within 3 months prior to screening, or surgery planned during the study. * Any history of malignant disease in the last 10 years, including leukemia, lymphoma or any significant hematology/oncology disease. Note: Participants with curatively resected non-melanoma skin cancers \>2 years prior to screening or curatively excised cervical carcinoma in situ \> 5 years prior to screening are not excluded. * Presence of clinically relevant immunosuppression from, but not limited to, immunodeficiency conditions such as common variable hypogammaglobulinemia. * History of risk factors for torsade de pointes (including a family history of long QT syndrome or sudden cardiac death or screening QTcF \> 450 msec in males or \> 470 msec in female) or a known arrhythmia (Note: asymptomatic first-degree heart block is not exclusionary). * Presence or having sequelae of gastrointestinal, liver (including Gilbert's syndrome), kidney, gallbladder, or other conditions known to interfere with the absorption, distribution, metabolism, or excretion of drugs. * Liver function test results elevated more than 1.3-fold above the upper limit of normal (ULN) for gamma glutamyl transferase (GGT), bilirubin (total), alkaline phosphatase (ALP), aspartate aminotransferase (AST) or alanine aminotransferase (ALT). * Estimated glomerular filtration rate (eGFR) \< 80 mL/min/1.73m2 using the 2021 CKD-EPI creatinine equation. * Positive test results for human immunodeficiency virus (HIV), hepatitis B surface antigen (HBsAg) or hepatitis C virus (HCV) antibodies at the screening visit.