An AE is defined as any untoward medical occurrence in a participant or clinical investigation participant, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of a medicinal product. An SAE is defined as any untoward medical occurrence that, at any dose, results in death, is life threatening, requires hospitalization or prolongation of existing hospitalization, results in disability/incapacity, is a congenital anomaly/birth defect, may jeopardize the participant or require medical or surgical intervention to prevent one of the other outcomes listed in the definition above, or is an event of possible drug-induced liver injury. There were no SAEs reported in this study.

Supine vital signs SBP and DBP were recorded whilst the participant was in a supine position (participant lying flat with maximum one pillow) having rested in that position for at least 10 minutes before each reading. Measurements were performed at 90 minutes, 3 hours, 24 hours and 72 hours post-dose. Baseline was defined as assessment performed pre-dose at Day 0. Change from Baseline was calculated by subtracting the Baseline value from the individual post-randomization values at the time of assessment.

Supine vital signs (heart rate) was recorded whilst the participant was in a supine position (participant lying flat with maximum one pillow) having rested in that position for at least 10 minutes before each reading. Measurements were performed at 90 minutes, 3 hours, 24 hours and 72 hours post-dose. Baseline was defined as assessment performed pre-dose at Day 0. Change from Baseline was calculated by subtracting the Baseline value from the individual post-randomization values at the time of assessment.

Full 12-lead ECGs were recorded using an ECG machine that automatically calculated the pulse rate and measured PR, RR, QRS, QT, QTc(b) intervals (Bazett's correction was applied to QTc measurements). Measurements were carried out at pre-dose, 1 hour and 3 hours on Day 1. ECG findings were characterized as abnormal-not clinically significant (A-NCS) and abnormal-clinically significant (A-CS). Data has been presented for A-NCS findings on Day 1.

Clinical chemistry parameters included albumin, alkaline phosphatase, alanine amino transferase, indirect bilirubin, calcium, chloride, creatinine, gamma glutamyl transferase, glucose, potassium, lactate dehydrogenase, triglycerides. Measurements were carried out at pre-dose, 24 hours, 48 hours and 72 hours. Data for number of participants with values outside clinical concern range defined as high and low have been presented.

Hematology parameters included eosinophils, hemoglobin, hematocrit, lymphocytes, mean corpuscle hemoglobin, mean corpuscle volume, platelet count, reticulocytes, white blood cell count (WBC). Measurements were carried out at pre-dose, 24 hours and 72 hours. Data for number of participants with values outside clinical concern range defined as high and low have been presented.

Approximately 10-20 mL mid-stream urine was collected into a sterile container and was screened by dipstick for: occult blood, proteins, ketones, glucose, red blood cells (RBC) and WBC. Sediment microscopy was performed only if any of the Multi-stick tests were abnormal. In such cases, microscopy was performed for: WBC, RBC, hyaline casts, granular casts, cellular casts. Data for number of participants with abnormal urinalysis results for positive parameters as assessed by dipstick and microscopic analysis have been presented.

Blood samples were taken for extraction of whole blood mRNA (2 x 2.5mL PAXgene tubes). The samples were taken at the time-points pre-dose, 45 minutes, 90 minutes and 3 hours. Messenger RNA levels for various markers was measured. These markers included Prednisolone markers: DDIT4, DUSP1, FKBP5, GILZ, IL1R2, TXNIP, ZNF145 and p38 markers: COX2, IFI30, IL1b, IL6, IL8, TNF. An aliquot of mRNA was stored for later analysis of other genes associated with the pathogenesis of RA and in the mode of action of the compounds administered.