Relative Bioavailability and Effect of Food and Esomeprazole on the Pharmacokinetics of PRN1008 in Healthy Volunteers.

INTERVENTION: This will be a single center, four‐period, open‐label, complete crossover (meaning subjects will receive all treatments) study to investigate: * The single dose pharmacokinetics of PRN1008 when administered as a liquid formulation compared to a tablet formulation under fasted conditions (no food for at least 8 hours prior to dosing, water permissible until 1 hour pre‐dose). * The effect of a meal on the single dose pharmacokinetics of PRN1008 when administered as a tablet formulation. * The effect of prior administration of a Proton Pump Inhibitor on the single dose pharmacokinetics of PRN1008 when administered as a tablet formulation. Participants will be screened for participation within 28 days before dosing. Participants will be admitted to the study unit the day before dosing (Day ‐1), then dosed in the mornings of Days 1, 3, 5 and 10, and will remain in the clinic up to Day 11, after collection of the final PK sample. All participants will complete all four Periods of the study Participants will be randomized to order of treatment (1, 2 & 3) for the first three Periods. All participants will receive Treatment 4 as the final treatment. Therefore, the final Period will be identical for all participants. Treatments are as listed below. Doses will be administered approximately 48 hours apart for the first three treatments: Treatment 1 Immediately prior to and following a single oral 300 mg dose of PRN1008 liquid formulation, blood samples will be obtained over a period of 24 hours for determination of the PRN1008 PK profile. Participants will be in a fasted state (i.e an overnight fast ‐no food‐of at least 8 hours, water permissible until 1 hr pre‐dose).Food will be restricted until 4 hours after dosing. Treatment 2 Immediately prior to and following a single oral 300 mg dose of PRN1008 tablet formulation, blood samples will be obtained over a period of 24 hours for determination of the PRN1008 PK profile. Participants will be in a fasted state (i.e an overnight fast ‐no food‐of at least 8 hours, water permissible until 1 hr pre‐dose).Food will be restricted until 4 hours after dosing. Treatment 3 Immediately prior to and following a single oral 300 mg dose of PRN1008 tablet formulation, blood samples will be obtained over a period of 24 hours for determination of the PRN1008 PK profile. Participants will be in a fed state (following an overnight fast of at least 8 hours, and water restricted for 1 hour before food administration, participants will receive a standardized moderate fat meal (breakfast). The meal will be started 30 minutes prior to dosing and ingested within 30 minutes.Further food will be restricted until 4 hours after dosing. Treatment 4 Following collection of the final PK sample from Period 3, participants will begin dosing esomeprazole 40 mg once daily (oral capsule) in the morning, on Days 6 – 10. On Day 10, immediately prior to and following a single oral 300 mg dose of PRN1008 tablet formulation, blood samples will be obtained over a period of 24 hours for determination of the PRN1008 PK profile. The Day 10 PRN1008 dose will be administered in a fasted state (i.e an overnight fast ‐no food‐of at least 8 hours, water permissible until 1 hr pre‐dose). Food will be restricted until 4 hours after dosing. All doses are administered and monitored by study staff to ensure compliance. There are 6 possible sequences in which the listed treatments will be completed: * 1234 * 1324 * 2134 * 2314 * 3124 * 3214 Following discharge from the study unit, subjects will return for a follow‐up assessment one week (plus or minus 2 days) after final study drug administration. The total duration for participants will be up to approximately 47 days. CONDITION: Inflammatory Bowel Disease Rheumatoid Arthritis Systemic Lupus Erythematosus PRIMARY OUTCOME: Impact of food on the PK of PRN1008 (AUC, Cmax) when administered as a tablet as determined by plasma assay. ; Relative oral bioavailability (AUC, Cmax) of PRN1008 when administered as a tablet (test formulation) compared to a liquid (reference formulation) as determined by plasma assay. ; Single dose PK of PRN1008, including plasma Cmax, Tmax, AUC and plasma half‐life. SECONDARY OUTCOME: Additional Primary outcome: ; Impact of prior administration of esomeprazole on the PK of PRN1008 (AUC, Cmax) as determined by plasma assay. ; ; Safety and tolerability, including the assessment of physical examinations, ECGs, vital signs, clinical laboratory results and adverse events. INCLUSION CRITERIA: * Healthy adult male or non‐pregnant non‐lactating females, 18 to 75 years of age (inclusive) at the time of screening * Body mass index (BMI) greater than or equal to 18 and less than or equal to 35 (kg/m2) (inclusive) and a minimum body weight of 45 kg. * Able to participate and comply with all study procedures and restrictions, and willing to provide written informed consent to participate in the study. * A female subject of childbearing potential with a negative pregnancy test agrees to abstinence or use of condoms plus one other acceptable form of contraception; i.e. intrauterine device, hormonal contraception, or a female diaphragm, until 4 weeks after dosing with study drug OR has only same‐sex partners, when this is her preferred and usual lifestyle * Male subjects with female partners of childbearing potential must agree to use condoms for the duration of the study and until 4 weeks after dosing with the study drug *Negative urine drug