Study of ABS-201 Evaluating Single and Multiple Ascending Doses in Adults With and Without Androgenetic Alopecia

Inclusion Criteria (Major): * Participants must be overtly healthy, as determined by medical evaluation, which includes a review of medical and surgical history, physical examination, and a 12-lead ECG. * Must have normal ranges for hematology, clinical chemistry, coagulation tests, and urine analysis parameters * Participants, male and female, must be willing to avoid pregnancy for the duration of the trial. * Participants must be capable of giving signed informed consent * Participants must have no signs or symptoms of active or latent tuberculosis (TB), Additional Inclusion criteria for patients with AGA: * Diagnosis of AGA with a Norwood-Hamilton Scale III vertex to V pattern. * Willing to clip target hair area for analysis and avoid scalp pigmentation products. * Willingness to maintain approximately the same hair length at each study visit Exclusion Criteria (Major): * History or presence of cancer, except for basal cell carcinoma or cervical dysplasia successfully treated with no recurrence for ≥90 days before screening. * History of liver disease, Gilbert's syndrome, or abnormal liver function tests (e.g., ALT, AST, or bilirubin \> ULN) at screening * Systolic blood pressure ≤90 or ≥140 mmHg, diastolic BP ≤40 or ≥90 mmHg, pulse rate \<40 or \>100 bpm * Positive test for HIV, hepatitis B (HBV), or hepatitis C (HCV). * Recent blood donation * Any clinically significant psychiatric disorder * Pregnant or breastfeeding females or those planning pregnancy during the study. * History of postpartum depression, perimenopausal mood instability, or estrogen withdrawal syndrome Additional Exclusion criteria for participants with AGA undergoing hair assessments: • Prior use of hair loss treatments: 1. Topical minoxidil within 3 months before screening. 2. Oral minoxidil other hair growth stimulators within 6 months before screening. 3. Finasteride within 6 months before screening 4. Dutasteride within 12 months before screening. * Use of GLP-1 receptor agonists (e.g., semaglutide, liraglutide, dulaglutide, exenatide, tirzepatide, or similar agents) within 3 months prior to screening * History of hair transplantation or other major scalp procedures or planned procedures during the study. * Use of hair extensions, wigs, hairpieces, weaves, or any other artificial hair enhancement methods within 30 days prior to screening and throughout the study. * History of clinically significant dermatologic disease of the scalp that could interfere with hair assessments or target area imaging