The goal of this clinical trial is to learn if ABS-201 (a new medication) is safe and tolerable when used to improve hair growth in men and women. The trial will start with healthy volunteers and if safe, will treat participants with certain types of hair loss.

The main questions it aims to answer are:

What medical problems, if any, do participants experience when taking a single dose or many doses of ABS-201? How does the medication, ABS-201, compare to placebo (a look alike substance that does not contain any medication).

Participants who qualify for the trial will receive either ABS-201 or a placebo, and visit the study clinic for scheduled checkups and tests for approximately 1 year.

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
• Must have a body mass index (BMI) of 18 to 32 kg/m2, inclusive, at screening, with a total body weight >60 kg.
• 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
• Additional Inclusion Criteria for postmenopausal women with AGA: Diagnosis of AGA with a Ludwig Scale I-3, I-4, II-1, II-2 pattern, with a documented history of AGA for ≥12 months and no rapid progression (e.g., sudden shedding, acute diffuse thinning, or scarring alopecia) in the 6 months prior to screening.

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

Biological males and biological females

The IPD sharing plan is not yet developed. The study team will consider data sharing at a later date.