The sponsor is developing a pediatric minitablet formulation as part of the overall pharmaceutical development strategy. In vitro dissolution and physiological-based bio-pharmaceutics modelling and simulation have been used to guide the development of the mini-tablet formulation to match the PK exposure of the adult capsule formulation. The study aims to investigate the relative bioavailability of the 50mg minitablet compared to the adult obefazimod 50 mg capsule in adult healthy volunteers.

This is a single center, open-label, two-part study in healthy male and female participants.

Part 1 of this study aims to investigate the PK properties of single dose of obefazimod 50 mg minitablet formulation and to identify a dose that provides systemic exposures (Cmax and AUC) comparable to that of the adult clinical obefazimod 50 mg capsule formulation.

In part 2, the minitablet formulation will be administered with a soft food vehicle (applesauce, yogurt or chocolate pudding or water) to investigate the relative bioavailability of the 50mg minitablet mixed with water or soft foods compared to the adult obefazimod 50 mg capsule administered with no vehicle.

Inclusion Criteria:

• Aged 18 to 55 years inclusive at the time of signing informed consent
• Must agree to adhere to the contraception requirements.
• Healthy male or non-pregnant, non-lactating female participants according to the assessment of the investigator, as based on a complete medical history including a physical examination, vital signs, 12-lead ECG and laboratory safety tests without any clinically significant abnormalities
• Body mass index (BMI) of 18.0 to 32.0 kg/m2 as measured at screening
• Weight ≥50 kg at screening Inclusion criteria.

Exclusion Criteria:

• Presence or history of clinically significant allergy requiring treatment, as judged by the investigator.
• History of clinically significant cardiovascular, renal, hepatic, dermatological, respiratory or GI disease, neurological or psychiatric disorder, as judged by the investigator
• Participants with a history of cholecystectomy or gall stones
• Participants with chronic or recurrent infection
• Participants who have tested positive for tuberculosis
• Participants with a history of shingles within the last two months
• History of opportunistic infection while not on immunosuppressive therapy
• Part 2 only: Participant has a medical condition that may adversely affect taste or smell activity including but not limited to mouth ulcers, significant gum disease, and respiratory and/or sinus infection or cold
• Part 2 only: Participant does not agree to the consumption of, or has any known allergies to any of the food vehicles used in this study (applesauce, chocolate pudding, yogurt)
• Participants who have received any IMP (Investigational Medicinal Product) in a clinical research study within the 90 days prior to Day 1, or less than 5 elimination half-lives prior to Day 1, whichever is longer
• Participants who have previously been administered IMP in this study
• Donation of blood or plasma within the previous 3 months or loss of greater than 400 mL of blood
• Participants who are taking, or have taken, any prescribed or over-the-counter drug, hormone replacement therapy (HRT) or herbal remedies (other than up to 4 g of paracetamol per day and hormonal contraception) in the 14 days or 5 elimination half-lives, whichever is longer, before first IMP administration (see Section 11.4). Exceptions may apply, as determined by the investigator
• Having any vaccination or planned vaccination within 28 days before Day 1. Participants who received live vaccine within 3 months prior to screening and/or who are planning to receive such a vaccine during the study duration.
• History of any drug or alcohol abuse in the past 2 years
• Regular alcohol consumption in males >21 units per week and in females >14 units per week (1 unit = ½ pint beer, or a 25 mL shot of 40% spirit, 1.5 to 2 units = 125 mL glass of wine, depending on type)
• Current smokers and those who have smoked within the last 12 months
• Current users of e-cigarettes and nicotine replacement products and those who have used these products within the last 12 months
• Confirmed positive drugs of abuse test result at screening or admission