A Study to Evaluate the Amount of Drug That Becomes Available to the Blood Circulation When Inhaled by a Nebulizer and Dry Powder Inhaler in Healthy Subjects.

1. History of any clinically significant disease or disorder which, in the opinion of the PI, may either put the subject at risk because of participation in the study, or influence the results or the subject's ability to participate in the study.

2. History or presence of gastrointestinal, hepatic or renal disease, or any other condition known to interfere with absorption, distribution, metabolism, or excretion of drugs.

3. History of Gilbert's syndrome, history of cholecystectomy or gall stone.

4. History of tuberculosis, any other significant lung diseases like surgeries, asthma, chronic obstructive pulmonary disease.

5. Upper respiratory tract infections (excluding otitis media) within 14 days of the first study day, or lower respiratory tract infection within 3 months prior to Screening.

6. Any clinically significant illness, medical/surgical procedure, or trauma within 4 weeks of the first administration of IMP.

7. Any clinically significant abnormalities in clinical chemistry, haematology, or urinalysis results, at screening and first admission to the study unit (first treatment period) as judged by the PI.

8. Any clinically significant abnormal findings in vital signs at screening and first admission to the study unit (first treatment period), as judged by the PI, and defined as:

* Systolic BP \<90 mmHg or ≥140 mmHg and diastolic BP \<50 mmHg or ≥90 mmHg

* Heart rate \<50 bpm or \>90 bpm

9. Any clinically significant abnormalities on 12-lead ECG at screening and first admission to the study unit (first treatment period), as judged by the PI, and defined as:

* Sick sinus syndrome

* Arrhythmia

* Prolonged QT interval corrected using Fridericia's formula \> 450 ms

10. Any positive result at screening for serum hepatitis B surface antigen (HBsAg), hepatitis C virus (HCV) antibody or human immunodeficiency virus (HIV) results.

11. Has received another new chemical entity (defined as a compound which has not been approved for marketing) within 3 months of the first administration of IMP in this study. The period of exclusion begins 3 months after the final dose or 1 month after the last visit whichever is the longest. Note: subjects consented and screened, but not randomised in this study or other clinical studies, are not excluded.

12. Plasma donation within 1 month of screening or any blood donation/loss more than 500 mL during the 3 months prior to screening.

13. History of severe allergy/hypersensitivity or ongoing allergy/hypersensitivity to AZD7594 or formulation excipients, as judged by the PI or history of hypersensitivity to drugs with a similar chemical structure or class to AZD7594.

Note: subjects with hay fever are allowed to participate, unless hay fever is active

14. Current smokers or those who have smoked or used nicotine products (including e-cigarettes; \>10 pack-year) within the 6 months prior to screening.

15. Known or suspected history of alcohol or drug abuse or excessive intake of alcohol as judged by the PI or positive screen for drugs of abuse, cotinine, and/or alcohol at screening or on each admission to the clinical unit.

16. Use of drugs with enzyme-inducing properties within 3 weeks prior to the first administration of IMP or herbal preparations/medications including, but not limited to, St. John's wort, kava, ephedra (ma huang), gingko biloba, dehydroepiandrosterone, yohimbe, saw palmetto, and ginseng. Subjects should stop using these herbal medications 14 days prior to the first administration of IMP.

17. Use of any prescribed or non-prescribed medication including antacids, analgesics (other than paracetamol/acetaminophen), herbal remedies, megadose vitamins (intake of 20 to 600 times the recommended daily dose) and minerals during the 2 weeks prior to the first administration of IMP or longer if the medication has a long half-life.

Note: Hormonal replacement therapy (HRT) and systemic contraceptives are allowed for females.

18. Subjects not able to perform a technically acceptable spirometry and/or not able to use the DPI correctly or not able to tolerate the pre-defined inhalation/nebulization.

19. Subjects with a pregnant partner.

20. Involvement of any AstraZeneca, PAREXEL or study site employee or their close relatives.

21. Subjects who have previously received AZD7594.

22. Vulnerable subjects, eg, kept in detention, protected adults under guardianship, trusteeship, or committed to an institution by governmental or juridical order.

What this study is about