An AE is any untoward medical occurrence in a clinical investigation participant, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product. 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, is a congenital anomaly/ birth effect, other situations and is associated with liver injury or impaired liver function. The analysis was performed on Safety analysis Population which comprised of all participants exposed to at least 1 application of study medication.

The investigator assessed application site tolerability focusing on the treated non-lesional skin surrounding the plaques at each visit using the 5-point tolerability assessment scale ranging from 0 (no intolerance) to 4 (very severe intolerance). Number of participants in the corresponding score at Day 1, 15, 29 and 57 has been presented.

Urine samples were collected from participants to evaluate urinalysis parameters including glucose, protein, erythrocytes and ketones. Number of participants with negative or normal urinalysis results at Day 15, Day 29 and Day 57 are presented. Last observation values collected prior to the first application of study treatment were considered as Baseline values.

The pH scale measures how acidic or basic a substance is. The pH scale ranges from 0 to 14. A pH of 7 is neutral. A pH less than 7 is acidic. A pH greater than 7 is basic. Urine samples were collected from participants and urine pH levels were assessed at Baseline, Day 15, Day 29 and Day 57. Last observation values collected prior to the first application of study treatment were considered as Baseline values. Change from Baseline was calculated as post-Baseline visit values minus Baseline value.

Urine samples were collected from participants and specific gravity levels were assessed at Baseline, Day 15, Day 29 and Day 57. Last observation values collected prior to the first application of study treatment were considered as Baseline values. Change from Baseline was calculated as post-Baseline visit values minus Baseline value.

Blood samples were collected from participants to evaluate clinical chemistry parameters including BUN, glucose, potassium, sodium and calcium. Change from Baseline in clinical chemistry parameters at Day 15, Day 29 and Day 57 are presented. Last observation values collected prior to the first application of study treatment were considered as Baseline values. Change from Baseline was calculated as post-Baseline visit values minus Baseline value.

Blood samples were collected from participants to evaluate clinical chemistry parameters including creatinine, total and direct bilirubin. Change from Baseline in clinical chemistry parameters at Day 15, Day 29 and Day 57 are presented. Last observation values collected prior to the first application of study treatment were considered as Baseline values. Change from Baseline was calculated as post-Baseline visit values minus Baseline value.

Blood samples were collected from participants to evaluate clinical chemistry parameters including AST, ALT and alkaline phosphatase. Change from Baseline in clinical chemistry parameters at Day 15, Day 29 and Day 57 are presented. Last observation values collected prior to the first application of study treatment were considered as Baseline values. Change from Baseline was calculated as post-Baseline visit values minus Baseline value.

Blood samples were collected from participants to evaluate clinical chemistry parameters including protein and albumin. Change from Baseline in clinical chemistry parameters at Day 15, Day 29 and Day 57 are presented. Last observation values collected prior to the first application of study treatment were considered as Baseline values. Change from Baseline was calculated as post-Baseline visit values minus Baseline value.

Blood samples were collected from participants to evaluate clinical hematology parameters including platelets, leukocytes, neutrophils, lymphocytes, monocytes, eosinophils and basophils. Change from Baseline in clinical hematology parameters at Day 15, Day 29 and Day 57 are presented. Last observation values collected prior to the first application of study treatment were considered as Baseline values. Change from Baseline was calculated as post-Baseline visit values minus Baseline value.

Blood samples were collected from participants to evaluate clinical hematology parameters including erythrocytes. Change from Baseline in clinical hematology parameters at Day 15, Day 29 and Day 57 are presented. Last observation values collected prior to the first application of study treatment were considered as Baseline values. Change from Baseline was calculated as post-Baseline visit values minus Baseline value.

Blood samples were collected from participants to evaluate clinical hematology parameters including hemoglobin. Change from Baseline in clinical hematology parameters at Day 15, Day 29 and Day 57 are presented. Last observation values collected prior to the first application of study treatment were considered as Baseline values. Change from Baseline was calculated as post-Baseline visit values minus Baseline value.

Blood samples were collected from participants to evaluate clinical hematology parameters including hematocrit. Change from Baseline in clinical hematology parameters at Day 15, Day 29 and Day 57 are presented. Last observation values collected prior to the first application of study treatment were considered as Baseline values. Change from Baseline was calculated as post-Baseline visit values minus Baseline value.

Blood samples were collected from participants to evaluate clinical hematology parameters including MCV. Change from Baseline in clinical hematology parameters at Day 15, Day 29 and Day 57 are presented. Last observation values collected prior to the first application of study treatment were considered as Baseline values. Change from Baseline was calculated as post-Baseline visit values minus Baseline value.

Blood samples were collected from participants to evaluate clinical hematology parameters including MCH. Change from Baseline in clinical hematology parameters at Day 15, Day 29 and Day 57 are presented. Last observation values collected prior to the first application of study treatment were considered as Baseline values. Change from Baseline was calculated as post-Baseline visit values minus Baseline value.

Vital sign measurements including SBP and DBP were taken in a seated or supine position after 5-minutes of rest. Last observation values collected prior to the first application of study treatment were considered as Baseline values. Change from Baseline was calculated as post-Baseline visit values minus Baseline value.

Vital sign measurements including pulse rate were taken in a seated or supine position after 5-minutes of rest. Last observation values collected prior to the first application of study treatment were considered as Baseline values. Change from Baseline was calculated as post-Baseline visit values minus Baseline value.

Single measurements of 12-lead ECG were obtained using an ECG machine to measure RR heart rate. Last observation values collected prior to the first application of study treatment were considered as Baseline values. Change from Baseline was calculated as post-Baseline visit values minus Baseline value

Single measurements of 12-lead ECG were obtained using an ECG machine to measure PR interval, QRS duration, QT interval, QTcB and RR interval. Last observation values collected prior to the first application of study treatment were considered as Baseline values. Change from Baseline was calculated as post-Baseline visit values minus Baseline value

Blood samples were collected at indicated time points for pharmacokinetic (PK) analysis of GSK2981278. Non-quantifiable values in a profile occurring before the first measurable concentration were assigned a value of zero concentration. Single non-quantifiable values occurring between measurable concentrations in a profile were omitted. The analysis was performed on PK analysis Population which comprised of participants with at least one sample collected and analyzed for plasma drug concentration. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

An AE is any untoward medical occurrence in a clinical investigation participant, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product. 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, is a congenital anomaly/ birth effect, other situations and is associated with liver injury or impaired liver function. The analysis was performed on Safety analysis set Population which comprised of all participants exposed to at least 1 application of study medication. This analysis was planned but not performed for Part B as the study was terminated during Part A.

The investigator planned to assess application site tolerability focusing on the treated non-lesional skin surrounding the plaques at each visit using the 5-point tolerability assessment scale ranging from 0 (no intolerance) to 4 (very severe intolerance). Number of participants with Application site tolerability assessment score were planned to be analyzed. This analysis was planned but not performed for Part B as the study was terminated during Part A.

Blood samples were planned to be collected for evaluation of clinical chemistry parameters. Last observation values collected prior to the first application of study treatment were considered as Baseline values. Change from Baseline was calculated as by subtracting post-Baseline visit values minus Baseline value. This analysis was planned but not performed for Part B as the study was terminated during Part A.

Blood samples were planned to be collected for the analysis of hematology parameters. Last observation values collected prior to the first application of study treatment were considered as Baseline values. Change from Baseline was calculated as post-Baseline visit values minus Baseline value. This analysis was planned but not performed for Part B as the study was terminated during Part A.

Vital sign measurement includes SBP, DBP, temperature, pulse rate. This analysis was planned but not performed for Part B as the study was terminated during Part A.

Single measurements of 12-lead ECGs were planned to be obtained using an ECG machine. This analysis was planned but not performed for Part B as the study was terminated during Part A.

The TPSS is the measure of clinical effect of GSK2981278. TPSS Total score was calculated by adding the individual scores of erythema, scaling, and induration (plaque thickness), assessed by the investigator on a 5-point scale ranging from 0=none to 4=very marked. This analysis was planned but not performed for Part B as the study was terminated during Part A.

The PGA is a clinical tool for assessing the current state/severity of a participant's psoriasis. It is a static 5-point morphological assessment of overall disease severity, as determined by the investigator, using the clinical characteristics of erythema, plaque thickness, and scaling as guidelines. The 5-point scale ranges from 0=clear to 4=severe. Last observation values collected prior to the first application of study treatment were considered as Baseline values. Change from Baseline was calculated as by subtracting post-Baseline visit values minus Baseline value. Percent change from Baseline was calculated by dividing change from baseline value by Baseline value and multiplying it by 100. This analysis was planned but not performed for Part B as the study was terminated during Part A.

The PASI is a standard tool for assessing the severity of psoriasis that considers the overall severity of erythema, thickness, and scale, and the extent of body surface area (BSA) affected with psoriasis. The 3 clinical signs are each graded on a 5-point scale (0=none to 4=severe) and the percent BSA affected is scored on a 7-point scale (0= 0% skin with psoriasis to 6=\>=90% skin with psoriasis). The individual scores are multiplied by a weighted factor for each body region; the sum of these scores gives the overall PASI score. Higher scores indicate more severe disease. Last observation values collected were considered as Baseline values. Change from Baseline was calculated as post-Baseline visit values minus Baseline value. Percent change from Baseline was calculated by dividing change from baseline value by Baseline value and multiplying it by 100. This analysis was planned but not performed for Part B as the study was terminated during Part A.