Blood samples were collected from participants for measurement of Hgb values. The Baseline value was the latest pre-dose assessment. Change from Baseline at Week 4 was calculated by subtracting Baseline value from the post-dose visit value. The analysis was performed on All Treated Subjects Population which comprised of all participants who received at least one dose of GSK1278863.

Blood samples were collected from participants for measurement of Hgb values. The Baseline value was the latest pre-dose assessment. Change from Baseline at Week 4 was calculated by subtracting Baseline value from the post-dose visit value. The change in Hgb at Week 4 was classified into different categories (i.e., \<=-2.0, \>-2.0 to -1.0, \>-1.0 to 0, \>0 to 1.0, \>1.0 to 2.0, and \>2 g/dL), and the number of participants in each category were summarized.

Blood samples were collected from participants for measurement of Hgb values. Baseline is the average of Hgb measured at Week -2 and Day 1 visits. Change from Baseline at Day 29 was defined as post dose value at Day 29 minus Baseline value. The analysis was performed on intent-to-treat (ITT) Population which comprised of all randomized participants who received at least one dose of study treatment, had a Baseline and at least one corresponding on treatment assessment, including Hgb.

Baseline was defined as the value on Day 1. CFB was calculated by subtracting the baseline value from the post-dose value at Week 4. To model the dose-response relationship a four-parameter Emax model was used. E0 is the expected Hgb change from Baseline for a participant receiving placebo and experiencing the average Hgb Baseline observed in the study. Emax is the expected Hgb change from Baseline for a participant receiving the highest dose above which no further increase in response can be achieved. ED50 is the dose that attains the intermediate response. Gamma is the slope parameter. Minimal Effective Dose (MED) is defined as the smallest dose that achieves a placebo-corrected change of 0.5 g/dL over Week 4. Target dose (TD) is defined as the dose that achieves a placebo-corrected 1.0 g/dL change over Week 4. Maximum Acceptable Dose (MAD) is defined as the dose that achieves a placebo-corrected 2.0 g/dL change over Week 4.

Baseline Hgb value was the average of three Hgb values taken during screening period at Week (W) -4, W-2 and Day 1. Change from Baseline in Hgb was calculated as W4 value minus the Baseline value. To model the dose-response relationship a four-parameter Emax model was used. The dose response dataset was based on all non-missing data collected up to W4. Participants (par.) who had a Week 2 Hgb measurement, but a missing Week 4 Hgb measurement were included with a change from Baseline at Week 4 value imputed as twice the change from Baseline at Week 2. E0 is the expected Hgb change from Baseline for a par. receiving placebo and experiencing the average Hgb Baseline observed in the study. Emax is the expected Hgb change from Baseline for a par. receiving the highest dose above which no further increase in response can be achieved. ED50 is the dose that attains the intermediate response. Gamma is the slope parameter. Alpha is the coefficient of the model covariate for centred Baseline.

The original Hgb Criteria for Group 1- rhEPO naive participants with a stable baseline Hgb of 8.0-10.0 g/dL (8.0-10.0 g/dL USA site only) and for Group 2- rhEPO users with a stable baseline Hgb of 9.0-10.5 g/dL (9.0-10.5 g/dL USA site only); the Hgb target range was 9.0 to 10.5 g/dL (9.0-10.5 g/dL USA site only). The study amended Hgb Criteria for Group 1- rhEPO naive participants with a stable baseline Hgb of 8.0-11.0 g/dL and Group 2- rhEPO users with a stable baseline Hgb of 9.0-11.5 g/dL; Hgb target range - 10.0 to 11.5 g/dL. Data are presented for those participants following the original criteria ("Original") and those following the amended ("Amended") criteria. The primary objective was to characterize the ability of GSK1278863 to achieve mean Hgb response within the target range.

Modeled Hgb change from Baseline over 4 weeks of treatment. Change from Baseline is the actual value of Hgb at Week 4 minus the Baseline value. For modeled change at Week 4 participants required a Baseline and two or more non missing post-baseline values. Baseline is the average of Week -2, -1 and Day 1 values. The model included fixed effects for Baseline Hgb, treatment, and treatment by day interaction. Covariate analysis for modeled Hgb change was performed. Random effects were fitted in the intercept and the slope over time.

Modeled Hgb change from baseline over 4 weeks was derived using a random coefficient mixed effects linear regression model. The model included fixed effects for baseline Hgb, treatment and a treatment by day interaction. Random effects was fitted in the intercept and the slope over time. All data up until investigational product discontinuation was included for Hgb efficacy evaluable participants; where efficacy evaluable was defined as having a baseline and at least 2 on-treatment Hgb assessments. Baseline was the average of Week -2 , Week -1 and Day 1 visits. The change from Baseline was calculated by subtracting the Baseline value from the individual post-dose visit values.

The effect of an oral dose of GSK1278863 on the pharmacokinetics of pioglitazone will be assessed using the following PK parameters: maximum observed concentration (Cmax), area under the concentration-time curve from time zero (pre-dose) extrapolated to infinite time (AUC (0-infinity)

The effect of an oral dose of GSK1278863 on the pharmacokinetics of rosuvastatin will be assessed using the following PK parameters: Cmax and AUC (0-infinity)

The effect of trimethoprim on the pharmacokinetics of GSK1278863 and six predominant metabolites (GSK2391220 \[M2\], GSK2506104 \[M3\], GSK2487818 \[M4\], GSK2506102 \[M5\], GSK2531398 \[M6\], GSK2531401 \[M13\]) will be assessed using the following PK parameters: Cmax and AUC (0-infinity)

Plasma concentrations of GSK1278863 and its metabolites (GSK2391220 \[M2\], GSK2506104 \[M3\], GSK2487818 \[M4\], GSK2506102 \[M5\], GSK2531398 \[M6\], and GSK2531401 \[M13\]) and derived pharmacokinetic parameters including maximum observed concentration (Cmax), Time of occurrence of Cmax (tmax), Area under the concentration-time curve (AUC)

Change from baseline in QTcF interval at each time-point (average of at least three 12-lead Holter ECG replicates per time-point (Pre-dose, Day 1 \[0.25h, 0.5h, 1h, 2h, 3h, 4h, 5h, 6h, 8h, 12h, 18h\] and 24h) for 75 and 500 mg dose of GSK1278863 as compared with time-matched placebo

12-lead ECGs will be obtained at each time-point

Vital Signs includes. temperature, systolic and diastolic blood pressure (BP) and pulse

An AE is any untoward medical occurrence in a patient or clinical investigation subject, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product

Clinical Laboratory Tests includes Hematology, Clinical Chemistry and Urinalysis

Serial blood samples were collected from participants at indicated time points for Pharmacokinetic (PK) analysis of GSK1278863 and its metabolites (GSK2391220, GSK2487818, GSK2506102, GSK2531398, GSK2531403 and GSK2531401). Geometric mean and geometric coefficient of variation has been presented for all metabolites. NA indicates data is not available. Geometric coefficient of variation could not be calculated for CAPD cohort due to small number of participants. PK Population comprised of participants in the 'All Subjects' Population for whom a PK sample was obtained and analyzed.

Serial blood samples were collected from participants at indicated time points for PK analysis of GSK1278863 and its metabolites (GSK2487818 and GSK2531398). Geometric mean and geometric coefficient of variation has been presented for all metabolites. NA indicates data is not available. Geometric coefficient of variation could not be calculated for CAPD cohort due to small number of participants.

Serial blood samples were collected from participants at indicated time points for PK analysis of GSK1278863 and its metabolites (GSK2391220, GSK2487818, GSK2506102, GSK2531398, GSK2531403 and GSK2531401). Geometric mean and geometric coefficient of variation has been presented for all metabolites. NA indicates data is not available. Geometric coefficient of variation could not be calculated for CAPD cohort due to small number of participants. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

1\. To assess the relative bioavailability GSK1278863A following single-dose administration under fasting and fed (standard high fat/calorie meal) conditions