A Study to Assess the Relative Bioavailability and Safety of Different Formulations of AZD4831 in Fasted State in Healthy Volunteers.

This study will be a randomized, open-label, 2-period, 2-treatment, single-dose, single-center, crossover study conducted at a single Clinical Unit. A total of 30 healthy male and female participants will be randomized to ensure that at least 26 participants are evaluable .

The study will comprise of:

• A Screening Period of maximum 28 days.
• Period 1: single oral dose AZD4831 Formulation A or B on Day 1.
• Period 2: single oral dose AZD4831 Formulation A or B on Day 1.
• A final Follow-up Visit after the last administration of Investigational medicinal product (IMP) (14 days [+ 3 days] post final dose).

There will be a minimum washout period of at least 14 days from the first dose of AZD4831.

Participants will receive single doses of AZD4831 (2 different formulations) on 2 occasions under fasted conditions.

Participants will be given the following treatments and randomly assigned to the treatment sequence(s): AB, BA

• Treatment 1 (Reference), AZD4831 Formulation A, oral dosage form), fasted.
• Treatment 2 (Test), AZD4831 Formulation B, oral dosage from), fasted.

Inclusion criteria

• Provision of signed and dated, written informed consent prior to any study-specific procedures.
• Male participants must adhere to the contraception methods.
• Females must have a negative pregnancy test at screening and on admission to the Clinical Unit, must not be lactating and must be of non-childbearing potential, confirmed at screening by fulfilling one of the following criteria:

• Postmenopausal defined as amenorrhea for at least 12 months or more following cessation of all exogenous hormonal treatments and Follicle-stimulating hormone (FSH) levels in the postmenopausal range.
• Documentation of irreversible surgical sterilization by hysterectomy, bilateral oophorectomy or bilateral salpingectomy but not tubal ligation.
• Have a Body mass index (BMI) between 18.5 and 30 kg/m2 (inclusive) and weigh at least 50 kg and no more than 100 kg inclusive at Screening.

Exclusion criteria

• Any clinically significant abnormalities on 12-lead Electrocardiogram (ECG) at the Screening Visit, as judged by the Investigator.
• Any clinically significant illness, medical/surgical procedure, or trauma within 4 weeks of the first administration of IMP.
• History or presence of gastrointestinal, hepatic or renal disease, or any other condition known to interfere with absorption, distribution, metabolism, or excretion of drugs.
• Known or suspected Gilbert's syndrome.
• History or ongoing allergy/hypersensitivity to drugs (including, but not limited to rash, angioedema, acute urticaria).
• Use of drugs with enzyme-inducing properties such as St John's Wort within 3 weeks before the first administration of AZD4831.
• Participants who previously received AZD4831.
• Any of the following signs or confirmation of COVID-19 infection:

• Participant has a positive SARS-CoV-2 reverse transcription-PCR test result within 2 weeks before the Screening Visit or between the Screening Visit and Randomization.
• Clinical signs and symptoms consistent with COVID-19 (eg, fever, dry cough, dyspnea, sore throat, fatigue) 2 weeks before the Screening Visit or between the Screening Visit and Randomization.
• Participant has been hospitalized with COVID-19 infection within the last 3 months.