This is a multicenter, randomized, double-blind, placebo-controlled phase II study designed to explore the efficacy and safety of different doses of SAL0140 in primary aldosteronism.

Participants diagnosed with primary aldosteronism were randomly assigned to the low-dose group, high-dose group or placebo group for a double-blind treatment period. Participants subsequently entered an open-label period to assess long-term efficacy and safety.

Inclusion Criteria:

1. Aged ≥18 years , regardless of gender.
2. Diagnosed with primary aldosteronism (PA).
3. Mean seated office systolic blood pressure (msSBP) ≥145 mmHg.
4. Receiving stable background antihypertensive therapy.
5. Serum potassium tested at local laboratory ≥3.0 mmol/L and <5.0 mmol/L.
6. Morning serum cortisol >3 μg/dL.
7. Voluntarily participate in the trial and provide written informed consent. Agree to comply with trial contraception and reproductive restrictions.

Exclusion Criteria:

1. Mean seated office systolic blood pressure (msSBP) ≥180 mmHg and/or mean seated office diastolic blood pressure (msDBP) ≥110 mmHg.
2. History or diagnosis of malignant hypertension, hypertensive emergency, hypertensive crisis or hypertensive encephalopathy.
3. History or diagnostic evidence of other secondary hypertension.
4. Prior surgical resection for adrenal adenoma.
5. Medication compliance <80% or >120%.
6. PA complicated with acute coronary syndrome, myocardial infarction, percutaneous coronary intervention or stroke.
7. Receiving treatment with potassium-binding agents.
8. Any clinically significant abnormal laboratory findings that, in the Investigator's opinion, may interfere with the evaluation of efficacy and/or safety endpoints of the study.
9. Subjects with severe hepatobiliary diseases.
10. Positive test for human immunodeficiency virus antibody (HIV), hepatitis C antibody (HCV), treponema pallidum antibody (TP), or positive hepatitis B surface antigen (HBsAg).
11. Type 1 diabetes mellitus or poorly controlled type 2 diabetes mellitus.
12. Morbid obesity.
13. Receiving blood transfusion for anemia.
14. History of adrenal insufficiency.
15. History of solid organ or bone marrow transplantation.
16. Prior exposure to rituximab or cytotoxic chemotherapeutic agents.
17. Recent use of strong CYP3A inhibitors or CYP3A inducers.
18. Concomitant use of antihypertensive drugs, or other chemical drugs, biological products, traditional Chinese medicines or natural products deemed inappropriate by the Investigator.
19. Active malignancy or past medical history of malignant tumor.
20. Patients on hemodialysis or strict salt-restricted diet.
21. Gastrointestinal disorders or prior gastrointestinal surgery that may affect drug absorption or excretion.
22. Known or suspected hypersensitivity to aldosterone synthase inhibitors; known contraindication or hypersensitivity to any background concomitant medications.
23. History of substance abuse or chronic alcohol abuse.
24. Female subjects who are pregnant, breastfeeding, or with positive pregnancy test result.
25. Recent blood donation or major blood loss (>400 mL), or clinically diagnosed hypovolemia.
26. Participation in any interventional clinical trial with investigational product within 3 months prior to screening (or within 5 half-lives of the investigational product, whichever is longer); or enrollment in any medical device clinical trial with implanted/used study device.
27. Night shift work within 3 days prior to study visit and within 3 days before ambulatory blood pressure monitoring.
28. Presence of clinically significant, unstable or uncontrolled concomitant diseases as assessed by the Investigator at screening.
29. Any other conditions judged by the Investigator to render the subject unsuitable for trial participation and likely to confound efficacy and/or safety assessment.