The goal of this clinical trial is to learn if intervention can treat sarcopenia in the elderly. Researchers will compare IN-207907 120 mg, 240 mg, 360 mg and placebo to see if SPPB score improves.

Inclusion Criteria:

• Subjects aged ≥ 65 years (for female subjects, those who are medically unable to become pregnant)
• Subjects diagnosed with sarcopenia in accordance with the Korean Working Group on Sarcopenia (KWGS) guidelines
• Subjects with a body weight of ≥ 35 kg and a body mass index (BMI) of ≥ 15 kg/m² and < 30 kg/m²
• Subjects with a nutritional status screening score of ≥ 8 as assessed by the Mini Nutritional Assessment (MNA) questionnaire

Exclusion Criteria:

• Subjects with a history of diseases or surgical procedures that may affect physical activity or function
• Subjects with underlying muscle disorders, including myopathy or muscular atrophy
• Subjects with neuromuscular or neurological disorders
• Subjects with uncontrolled diabetes mellitus, severe renal impairment, uncontrolled thyroid disorders, vitamin D deficiency, severe hepatic impairment, severe cardiac disease, uncontrolled hypertension, respiratory disorders
• Subjects with clinically significant findings on a 12-lead electrocardiogram (ECG)
• Subjects who are positive for active hepatitis B, active hepatitis C, syphilis, or human immunodeficiency virus
• Subjects with a history of malignancy within 5 years
• Subjects who have received systemic immunosuppressants or immunostimulants
• Subjects who have undergone treatment with plasmapheresis within 8 weeks
• Subjects who have received treatment with medications prohibited in this clinical trial within 4 weeks
• Subjects with hemoglobin levels < 10 g/dL
• Subjects who have undergone surgery requiring general anesthesia within 4 weeks
• Subjects who are unable to walk or are physically inactive
• Subjects who are participating in or planning to participate in a separate high-intensity program for increasing muscle mass or strength during the clinical trial period
• Subjects with severe psychiatric disorders such as major depression, schizophrenia, alcoholism, or drug dependence
• Subjects with a score of < 24 on the Korean version of the Mini Mental State Examination (MMSE-K)
• Subjects with known allergies or hypersensitivity to the investigational product or its excipients