Eligibility Criteria:
Inclusion Criteria:
1. Provision of signed and dated, written informed consent prior to any study specific procedures.
2. Agree to use the methods of contraception
3. Healthy male Japanese participants aged 18 to 50 years (inclusive) with suitable veins for cannulation or repeated venipuncture. A Japanese participant is defined as having both parents and 4 grandparents who are ethnically Japanese. This includes second and third generation Japanese whose parents or grandparents are living in a country other than Japan.
4. Have a body mass index (BMI) between 18 and 30 kg/m2 inclusive and weigh at least 50 kg and no more than 100 kg inclusive.
5. Provision of signed, written and dated informed consent for optional genetic/biomarker research. If a participant decline to participate in the genetic and/or biomarker component of the study, there will be no penalty or loss of benefit to the participant. The participant will not be excluded from other aspects of the study described in this protocol.
Exclusion Criteria:
1. History of any clinically important disease or disorder which, in the opinion of the Investigator, may either put the participant at risk because of participation in the study, or influence the results or the participant'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. Any clinically important illness, medical/surgical procedure or trauma within 4 weeks of the first administration of IMP.
4\. Any clinically important abnormalities in clinical chemistry, hematology or urinalysis results at the Screening Visit and/or admission.
4.1. Serum potassium \> 5.0 mmol/L 4.2. Hemoglobin A1c (HbA1c) \> 5.7% 5. Any positive result on Screening for serum hepatitis B surface antigen (HBsAg), hepatitis C antibody and human immunodeficiency virus (HIV).
6\. Abnormal vital signs, after 10 minutes supine rest at the Screening Visit and/or admission 7. Any clinically important abnormalities in rhythm, conduction or morphology of the resting electrocardiography (ECG) and any clinically important abnormalities in the 12 Lead ECG as judged by the Investigator that may interfere with the interpretation of QTc interval changes, including abnormal ST-T-wave morphology, particularly in the protocol defined primary lead or LV hypertrophy at the Screening Visit and/or admission.
8\. Known or suspected history of drug abuse in the last 12 months before the Screening Visit as judged by the Investigator.
9\. Current smokers or those who have smoked or used nicotine products (including e-cigarettes) within the previous 3 months.
10\. History of alcohol abuse in the last 12 months before the Screening Visit or current excessive intake of alcohol as judged by the Investigator.
11\. Positive screen for drugs of abuse, alcohol or cotinine (nicotine) at Screening or admission.
12\. History of severe allergy/hypersensitivity or ongoing clinically important allergy/hypersensitivity, as judged by the Investigator or history of hypersensitivity to drugs with a similar chemical structure or class to AZD9977.
13\. Excessive intake of caffeine-containing drinks or food (e.g., coffee, tea, chocolate,) as judged by the Investigator.
14\. Use of drugs with enzyme inducing properties such as St John's Wort within 3 weeks prior to the first administration of IMP.
15\. Use of any prescribed or nonprescribed medication including antacids, analgesics (other than paracetamol/acetaminophen), herbal remedies, mega-dose 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.
16\. Plasma donation within 1 month of the Screening Visit or any blood donation/blood loss \> 500 mL during the 3 months prior to the Screening Visit.
17\. 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. Participants consented and screened, but not randomized in this study or a previous Phase I study, are not excluded.
18\. Participants who have previously received AZD9977. 19. Involvement of any Astra Zeneca or Clinical Unit employee or their close relatives.
20\. Judgment by the Investigator that the participant should not participate in the study if they have any ongoing or recent (i.e., during the Screening Period) minor medical complaints that may interfere with the interpretation of study data or are considered unlikely to comply with study procedures, restrictions and requirements.
21\. Vulnerable participants, e.g., kept in detention, protected adults under guardianship, trusteeship, or committed to an institution by governmental or juridical order.
In addition, any of the following is regarded as a criterion for exclusion from the genetic research:
22\. Previous bone marrow transplant. 23. Non-leukocyte depleted whole blood transfusion within 120 days of the date of the genetic sample collection.