DLco is a measure of the ability of a gas to transfer from alveoli across the alveolar epithelium and capillary endothelium to the red blood cells. Changes in DLco reflect the alveolar-capillary membrane conductance. Acute pulmonary congestion causes a reduction in DLco. In participants with heart failure, decrease in DLco serves as a predictor of disease progression. An impairment in the diffusing capacity of the lung may be related to symptoms and exercise intolerance associated with heart failure. DLco was measured just prior to and after the 3- minute step test on Days -1, and 7 and just prior to and after an intravenous saline infusion on Day 5. Day -1 was Baseline and change from Baseline was calculated from Day -1 pre-exercise of the respective period, except when calculating the post-infusion change from Baseline, where the pre-infusion value was used as Baseline. Data of DLco (milliliter per millimeter of mercury per minute [mL/mmHg/min]) for Mayo site is presented.

Analysis Population comprised of participants in the 'All Subjects' population having Baseline and post-Baseline assessments of the endpoint of interest for both periods. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

DLco is a measure of the ability of a gas to transfer from the alveoli across the alveolar epithelium and the capillary endothelium to the red blood cells. Changes in DLco reflect the alveolar-capillary membrane conductance. Acute pulmonary congestion cause a reduction in DLco. In participants with heart failure, decrease in DLco serves as a predictor of disease progression. An impairment in the diffusing capacity of the lung may be related to the symptoms and exercise intolerance associated with heart failure. DLco was measured just prior to and after the 3- minute step test on Days -1, and 7 and just prior to and after an intravenous saline infusion on Day 5. Day -1 was Baseline and change from Baseline was calculated from Day -1 Pre-Exercise of the respective period, except when calculating the post-infusion change from Baseline, where the pre-infusion value was used as the Baseline. Statistical analysis was not performed as the sample size was too small

Analysis Population. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

DLno is a measure of the ability of a gas to transfer from the alveoli across the alveolar epithelium and the capillary endothelium to the red blood cells. Changes in DLco reflect the alveolar-capillary DM. Since nitric oxide has a greater affinity for hemoglobin, transfer of gas mainly limits the diffusion of nitric oxide across the alveolar capillary membrane. Day -1 was Baseline and change from Baseline was calculated from Day -1 pre-exercise of the respective period, except when calculating the post-infusion change from Baseline, where the pre-infusion value was used as Baseline. The data is presented only for participants from the Mayo Clinic as the data was not collected at Hennepin.

Analysis Population. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

Vc is defined as volume of blood within the capillaries. Day -1 was Baseline and change from Baseline was calculated from Day -1 pre-exercise of the respective period, except when calculating the post-infusion change from Baseline, where the pre-infusion value was used as the Baseline. The data is presented only for participants from the Mayo Clinic as the data was not collected at Hennepin.

Analysis Population. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

DLco is a measure of the ability of a gas to transfer from the alveoli across the alveolar epithelium and the capillary endothelium to the red blood cells. Changes in DLco reflect the alveolar-capillary membrane conductance. Acute pulmonary congestion causes a reduction in DLco. In participants with heart failure, decrease in DLco serves as a predictor of disease progression. DLco was measured just prior to and after the 3- minute step test on Days -1, and 7 and just prior to and after an intravenous saline infusion on Day 5. Day -1 was Baseline and change from Baseline was calculated from Day -1 pre-exercise of the respective period, except when calculating the post-infusion change from Baseline, where the pre-infusion value was used as the Baseline. Data for DLco following exercise and following an intravenous saline infusion is presented for Mayo site.

Analysis Population.

DLco is a measure of the ability of a gas to transfer from the alveoli across the alveolar epithelium and the capillary endothelium to the red blood cells. Changes in DLco reflect the alveolar-capillary membrane conductance. Acute pulmonary congestion cause a reduction in DLco. In participants with heart failure, decrease in DLco serves as a predictor of disease progression. DLco was measured just prior to and after the 3- minute step test on Days -1, and 7 and just prior to and after an intravenous saline infusion on Day 5. Day -1 was Baseline and change from Baseline was calculated from Day -1 pre-Exercise of the respective period, except when calculating the post-infusion change from Baseline, where the pre-infusion value was used as the Baseline. Data for DLco following exercise and following an intravenous saline infusion is presented for Hennepin site is presented.

Analysis Population. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

Participants were asked to participate in a submaximal exercise test that consisted of 3 parts: a 2-minute (min) resting Baseline, a 3-min step exercise and a 1-min recovery period. Throughout the test, breathing pattern, gas exchange, and heart rate were monitored using a simplified gas analysis system. Respiratory exchange ratio and the Borg Rating of Perceived Exertion measures were utilized to ensure participants perform progressive exercise while maintaining a submaximal level throughout the exercise period. Minute ventilation, breath frequency, tidal volume, oxygen consumption, carbon dioxide (CO2) production, Respiratory exchange ratio (RER) and end tidal CO2 were obtained from the breath-by-breath gas measurements. The VE/VCO2 slope and other variables were derived from this data. Day -1 was Baseline and change from Baseline was calculated by subtracting the Baseline value from value at specified time point.

Analysis Population

FEV1 was defined as the volume of air that can be forced out in one second after taking a deep breath. FVC is the total amount of air exhaled during the lung function test. FEF is the the flow (or speed) of air coming out of the lung during the middle portion of a forced expiration. FEF 25-75, FEF50 and FEF75 is defined as a reduction in forced expiratory flow at 25 to 75 percent of the pulmonary volume. Results presented combines data across all sites. Day -1 was Baseline and change from Baseline was calculated by subtracting the Baseline value from value at specified time point.

Analysis Population. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

FRC is the volume of air present in the lungs at the end of passive expiration. FRC was planned to be measured by body plethysmography. Analysis was planned but not performed. FRC parameter was not collected because other measures which were collected served as reasonable surrogates.

Analysis Population. Analysis was planned but not performed. FRC parameter was not collected because other measures which were collected served as reasonable surrogates.

EELV corresponds to FRC in the presence of positive end expiration pressure (PEEP). Analysis was planned but not performed. EELV parameter was not collected because other measures which were collected served as reasonable surrogates.

Analysis Population. Analysis was planned but not performed. EELV parameter was not collected because other measures which were collected served as reasonable surrogates.

Dyspnea was assessed using a standardized, validated 5-point Likert scale. Participants were asked to check the box next to the statement that most accurately described their current state of breathlessness or shortness of breath. Scale consisted of 5 points : 1- Not short of breath, 2- Mildly short of breath, 3- Moderately short of breath, 4- Severely short of breath and 5- Very severely short of breath. Participants rated their current state of breathlessness on this 5 point scale. Day -1 was Baseline and change from Baseline was calculated by subtracting the Baseline value from value at specified time point .

Analysis Population. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

Continuous remote monitoring was performed during each 7-day study period utilizing the Preventice BodyGuardian Remote Monitoring System. Participants were instructed to wear the sensor throughout each study period. Respiratory monitoring data was collected in different body positions like standing, leaning, lying and unknown. Data is presented only for participants from Mayo clinic.

All Subjects population comprised of all randomized participants who received at least one dose of study medication. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

SBP and DBP were measured in a semi-supine position after 5 minutes rest at Baseline and up to 7 days of each treatment period. Day -1 was Baseline and change from Baseline was calculated by subtracting the Baseline value from specified time point value.

All Subjects Population. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

Heart rate was measured in a semi-supine position after 5 minutes rest at Baseline and up to 7 days of each treatment period. Day -1 was Baseline and change from Baseline was calculated by subtracting the Baseline value from value at specified time point.

All Subjects population. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

Respiration rate was measured in a semi-supine position after 5 minutes rest at Baseline and up to 7 days of each treatment period. Day -1 was Baseline and change from Baseline was calculated by subtracting the Baseline value from value at specified time point.

All Subjects population. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

Body temperature was measured in a semi-supine position after 5 minutes rest at Baseline and up to 7 days of each treatment period. Day -1 was Baseline and change from Baseline was calculated by subtracting the Baseline value from value at specified time point.

All Subjects population. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

Percent oxygen in blood was measured using pulse oximetry in a semi-supine position after 5 minutes rest at Baseline and up to 7 days of each treatment period. Day -1 was Baseline and change from Baseline was calculated by subtracting the Baseline value from value at specified time point.

All Subjects population. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

Triplicate 12-lead ECG was obtained using an automated ECG machine at Baseline (Day-1) and single ECG measurements (M) were taken on Day 4 and Day 7. Data for number of participants with abnormal-clinically significant (CS) and abnormal-not clinically significant (NCS) ECG data is presented.

All Subjects Population. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

Blood samples were collected to analyze the chemistry parameters including ALT, ALP, AST, creatine kinase and GGT. Change from Baseline is presented for these parameters. Day -1 was Baseline and change from Baseline was calculated by subtracting the Baseline value from value at specified time point.

All Subjects Population. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

Blood samples were collected to analyze the chemistry parameters including albumin and total protein. Change from Baseline is presented for these parameters. Day -1 was Baseline and change from Baseline was calculated by subtracting the Baseline value from value at specified time point.

All Subjects Population. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

Blood samples were collected to analyze the chemistry parameters including Calcium, Chloride, Glucose, Potassium, Sodium, Urea/BUN. Change from Baseline is presented for these parameters. Day -1 was Baseline and change from Baseline was calculated by subtracting the Baseline value from specified time point value.

All Subjects Population. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

Blood samples were collected to analyze the chemistry parameters including Creatinine, Direct Bilirubin, Total Bilirubin and Uric acid. Change from Baseline was presented for these parameters. Day -1 was Baseline and change from Baseline was calculated by subtracting the baseline value from specified time point value.

All Subjects Population. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

Blood samples were collected to analyze the digoxin levels. Change from Baseline is presented for these parameters. Day -1 was Baseline and change from Baseline was calculated by subtracting the baseline value from specified time point value. NA indicates data not available. Standard deviation could not be calculated as a single participant was analyzed.

All Subjects Population. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

Blood samples were collected to analyze the troponin I level and type I collagen cross-linked C-telopeptide (T1CCT). Change from Baseline was presented for these parameters. Day -1 was Baseline and change from Baseline was calculated by subtracting the Baseline value from value at specified time point.

All Subjects Population. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

Blood samples were collected to analyze the Chemistry parameter N-terminal pro-Brain Natriuretic Peptide. Change from Baseline is presented for these parameters. Day -1 was Baseline and change from Baseline is calculated by subtracting the baseline value from specified time point value.

All Subjects Population. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

Blood samples were collected to analyze the Hematology parameters including Basophils, Eosinophils, Lymphocytes, Monocytes, Platelet count, White Blood Cell (WBC) count, Total Neutrophils. Change from Baseline is presented for these parameters. Day -1 was Baseline and change from Baseline was calculated by subtracting the Baseline value from specified time point value.

All Subjects Population. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

Blood samples were collected to analyze the Hematology parameter Hematocrit. Change from Baseline is presented for this parameter. Day -1 was Baseline and change from Baseline was calculated by subtracting the Baseline value from specified time point value.

All Subjects Population. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

Blood samples were collected to analyze Hemoglobin. Change from Baseline is presented for this parameter. Day -1 was Baseline and change from Baseline was calculated by subtracting the Baseline value from specified time point value.

All Subjects Population. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

Blood samples were collected to analyze Mean Corpuscle Volume. Change from Baseline is presented for this parameter. Day -1 was Baseline and change from Baseline was calculated by subtracting the Baseline value from specified time point value.

All Subjects Population. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

Blood samples were collected to analyze the Hematology parameters including RBC and Reticulocytes. Change from Baseline is presented for these parameters. Day -1 was Baseline and change from Baseline was calculated by subtracting the Baseline value from specified time point value.

All Subjects Population. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

Blood samples were collected to analyze Mean Corpuscle Hemoglobin concentration . Change from Baseline is presented for this parameter. Day -1 was Baseline and change from Baseline was calculated by subtracting the Baseline value from specified time point value. NA indicates data was not available. Standard deviation could not be calculated as a single participant was analyzed at the specified time point

All Subjects Population. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

Blood samples were collected to analyze Mean Corpuscle Hemoglobin. Change from Baseline was presented for this parameter. Day -1 was Baseline and change from Baseline was calculated by subtracting the baseline value from specified time point value. NA indicates data was not available. Standard deviation could not be calculated as a single participant was analyzed at the specified time point

All Subjects Population. 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. Any untoward event resulting in death, life threatening, requires hospitalization or prolongation of existing hospitalization, results in disability/incapacity, congenital anomaly/birth defect, any other situation according to medical or scientific judgment or all events of possible drug-induced liver injury with hyperbilirubinemia were categorized as SAE. Number of participants with AE and SAE are reported.

All Subjects Population.

The SF-36 is a participant self-rated questionnaire that is a general measure of perceived health status comprising 36 questions, which yields an 8-scale health profile. The vitality sub-score assesses energy and fatigue, and ranges from 0 (worst) - 100 (best). Day -1 was Baseline and change from Baseline was calculated by subtracting the Baseline value from specified time point value.

Analysis Population. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

AUC(0-t), AUC(0-tau) and AUCall for GSK2798745 were determined based on intensive Pharmacokinetic (PK) sampling at the following time points: Pre-dose, 0.5, 1, 1.5, 2, 3, 5, 8 and 12 hours on Day 1, pre-dose and at 12 hours post dose on Day 2, pre-dose on Days 3 to 6, Pre-dose, 0.5, 1, 1.5, 2, 3, 5 and 10 hours on Day 7 and at 24 and 48 hours. PK parameter population included all participants in the PK Concentration Population for whom valid and evaluable pharmacokinetic parameters were derived

PK Parameter Population. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

Blood samples for PK analysis were collected at pre-dose, 0.5, 1, 1.5, 2, 3, 5, 8 and 12 hours on Day 1, pre-dose and at 12 hours post dose on Day 2, pre-dose on Days 3 to 6, Pre-dose, 0.5, 1, 1.5, 2, 3, 5 and 10 hours on Day 7 and at 24 and 48 hours on Days 8 and 9. Cmax was defined as maximum observed plasma concentration of drug.

PK Parameter. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

Blood samples for PK analysis were collected at pre-dose, 0.5, 1, 1.5, 2, 3, 5, 8 and 12 hours on Day 1, pre-dose and at 12 hours post dose on Day 2, pre-dose on Days 3 to 6, Pre-dose, 0.5, 1, 1.5, 2, 3, 5 and 10 hours on Day 7 and at 24 and 48 hours on Days 8 and 9. Tmax was defined as time to maximum observed plasma concentration of drug.

PK Parameter population. Only those participants with data available at the specified data points were analyzed (represented by n= X in the category titles).

Blood samples for PK analysis were planned to be collected at pre-dose, 0.5, 1, 1.5, 2, 3, 5, 8 and 12 hours on Day 1, pre-dose and at 12 hours post dose on Day 2, pre-dose on Days 3 to 6, Pre-dose, 0.5, 1, 1.5, 2, 3, 5 and 10 hours on Day 7 and at 24 and 48 hours on Days 8 and 9. T½ was defined as Elimination half life of drug. Data is not available for t1/2. The analysis was planned but not performed. PK sampling scheme was not adequate enough to reliably estimate the t1/2 of GSK2798745.

PK Parameter Population. Data is not available for t1/2. The analysis was planned but not performed. PK sampling scheme was not adequate enough to reliably estimate the t1/2 of GSK2798745.