placebo matching lapatinib will be given as three separate doses (8 tablets/dose) given 12 hours apart over a 2 day period

The number of participants with 12-lead Holter ECG findings of normal (NL), abnormal not clinically significant (Abn NCS), and abnormal clinically significant (Abn CS) are reported. Abnormal ECG findings or change in ECG morphological patterns were based on the ECG interpretations provided by the ECG core lab. Three replicate 12-lead Holter ECGs were collected at -30, -15, and 0 minutes prior to the administration of study treatment on Days 1 (Baseline for placebo) and 3 (Baseline for lapatinib) and pre-dose and 1, 2, 3, 4, 6, 8, 10,12, and 24 hours post dose on Days 2 and 4. The three readings at each time point were averaged prior to any analysis. Baseline is the pre-dose ECGs (triplicate) taken on Day 1 for placebo and on Day 3 for lapatinib.

Abnormal ECG findings or change in ECG morphological patterns were based on the ECG interpretations provided by the ECG core lab. Three replicate Holter ECGs were collected at 30, 15, and 0 minutes prior to the administration of study treatment on Days 1 (Baseline for placebo) and 3 (Baseline for lapatinib) and pre-dose and 1, 2, 3, 4, 6, 8, 10, and 24 hours post dose on Days 2 and 4. The three readings at each time point were averaged prior to any analysis. Baseline is the pre-dose ECGs (triplicate) taken on Day 1 for placebo and Day 3 for lapatinib. The number of participants with the worst-case post-Baseline 12-lead Holter ECG findings with significant ST, T wave, and U wave abnormalities were analyzed.

An AE is defined as any untoward medical occurrence in a participant temporally associated with the use of a medicinal product, whether or not considered related to the 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 or is a congenital anomaly/birth defect, or is an important medical eventsthat jeopardizes the participant or may require medical or surgical intervention to prevent one of the other outcomes listed in the above definition, new primary cancers, liver events, cardiac dysfunction, pneumonitis, and laboratory abnormalities.

Blood samples were collected for the measurement of albumin and hemoglobin at Baseline; Days 5 and 8-11. Baseline is defined as the most recent, non-missing value from a central laboratory prior to or on the first study treatment dose date.

Blood samples were collected for the measurement of ALP, ALT, and AST at Baseline; Days 5 and 8-11. Baseline is defined as the most recent, non-missing value from a central laboratory prior to or on the first study treatment dose date.

Blood samples were collected for the measurement of direct bilirubin, total bilirubin, and creatinine at Baseline; Days 5 and 8-11; Baseline is defined as the most recent, non-missing value from a central laboratory prior to or on the first study treatment dose date.

Blood samples were collected for the measurement of calcium, chloride, CO2, potassium, sodium, magnesium and urea at Baseline; at Days 5 and 8-11. Baseline is defined as the most recent, non-missing value from a central laboratory prior to or on the first study treatment dose date.

Blood samples were collected for the measurement of total neutrophils (ANC), platelets, and leukocyte count at Baseline; Days 5 and 8-11. Baseline was defined as the most recent, non-missing value from a central laboratory prior to or on the first study treatment dose date.

Blood pressure measurements included SBP and DBP and were obtained at Baseline; on Day 2 (at pre-dose, 4, 8, 12 and 24 hours post dose), and on Day 4 (at pre-dose, 4, 8, 12 and 24 hours post dose). Baseline is defined as the most recent, non-missing value prior to or on the first study treatment dose date. Change from Baseline was calculated as the post-Baseline value minus the Baseline value.

Heart rate were measured at Baseline; on Day 2 (at pre-dose, 4, 8, 12 and 24 hours post dose), and on Day 4 (at pre-dose, 4, 8, 12 and 24 hours post dose. Baseline is defined as the most recent, non-missing value prior to or on the first study treatment dose date. Change from Baseline was calculated as the post-Baseline value minus the Baseline value.

The number of participants with the 12-lead ECG findings normal (NL), abnormal not clinically significant (Abn NCS), and abnormal clinically significant (Abn CS) are reported. Clinical significance was based on the medical and scientific judgement of the investigator or qualified designee. A single safety 12-lead ECG was performed using a standard 12-lead ECG machine at Baseline; on Day 1 (at pre-dose); on Day 2 (at pre-dose, 4, 8, 12 and 24 hours post-last- dose); on Day 4 (at pre-dose, 4, 8, 12 and 24 hours post-last-dose); at the End of Study visit (Day 8-11); and at the post-treatment Follow-up visit (if applicable).

AUC is defined as the area under the lapatinib concentration-time curve as a measure of drug exposure. AUC(0-t) and AUC(0-24) were determined from the plasma concentration-time data using the linear trapezoidal rule for increased concentrations and the logarithmic trapezoidal rule for decreased concentrations. For PK analysis, one blood sample was collected on Day 1 for placebo Baseline. The 24 hour blood sample on Day 2 also served for lapatinib Baseline. Pre-dose blood samples were collected 30 minutes prior to the administration of study medication on Day 2 (placebo) and Day 4 (lapatinib). Serial blood samples were collected on Day 2 (for placebo) and on Day 4 (for lapatinib) at the following post-last-dose time points 1, 2, 3, 4, 6, 8, 10, 12, and 24 hours.

The first occurrence of Cmax and C24 was determined directly from the raw concentration-time data. For PK analysis, one blood sample was collected on Day 1 for placebo Baseline. The 24 hour blood sample on Day 2 also served for lapatinib Baseline. Pre-dose blood samples were collected 30 minutes prior to the administration of study medication on Day 2 (placebo) and Day 4 (lapatinib). Serial blood samples were collected on Day 2 (for placebo) and on Day 4 (for lapatinib) at the following post-last-dose time points 1, 2, 3, 4, 6, 8, 10, 12, and 24 hours.

For each participant, the time at which Cmax was observed (tmax) was determined directly from the raw concentration-time data. For each participant, the time prior to the first quantifiable (non-zero) concentration (tlag) was determined directly from the raw concentration-time data. Since all participants received 2 doses of study medication prior to the collection of the first (pre-dose) blood sample on Day 4, tlag was expected to be zero. For PK analysis, one blood sample was collected on Day 1 for placebo Baseline. The 24 hour blood sample on Day 2 also served for lapatinib Baseline. Pre-dose blood samples were collected 30 minutes prior to the administration of study medication on Day 2 (placebo) and Day 4 (lapatinib). Serial blood samples were collected on Day 2 (for placebo) and on Day 4 (for lapatinib) at the following post-last-dose time points 1, 2, 3, 4, 6, 8, 10, 12, and 24 hours.

A Holter monitor is an ambulatory portable device for continuously monitoring the cardiovascular system. Change from Baseline in QT interval, QTc interval, QTcB interval, QTcI interval, RR interval, PR interval, and QRS duration at each time point for lapatinib was assessed in comparison with time-matched placebo. Three replicate ECGs were collected at 30, 15, and 0 minutes prior to the administration of study treatment on Days 1 and 3 and pre-dose and 1, 2, 3, 4, 6, 8, 10, and 24 hours post dose on Days 2 and 4. The three readings at each time point were averaged prior to any analysis. Baseline is the average of the pre-dose ECGs (triplicate) taken on Day 1 for placebo and Day 3 for lapatinib. Change from Baseline was calculated by subtracting the Baseline values from individual post-Baseline values for each time point.

Evaluable Population. Only participants available at the specified time point (represented as n=X, X in the category title) were analyzed.

The number of participants with 12-lead Holter ECG findings of normal (NL), abnormal not clinically significant (Abn NCS), and abnormal clinically significant (Abn CS) are reported. Abnormal ECG findings or change in ECG morphological patterns were based on the ECG interpretations provided by the ECG core lab. Three replicate 12-lead Holter ECGs were collected at -30, -15, and 0 minutes prior to the administration of study treatment on Days 1 (Baseline for placebo) and 3 (Baseline for lapatinib) and pre-dose and 1, 2, 3, 4, 6, 8, 10,12, and 24 hours post dose on Days 2 and 4. The three readings at each time point were averaged prior to any analysis. Baseline is the pre-dose ECGs (triplicate) taken on Day 1 for placebo and on Day 3 for lapatinib.

Evaluable Population. Only participants available at the specified time point (represented as n=X, X in the category title) were analyzed.

Abnormal ECG findings or change in ECG morphological patterns were based on the ECG interpretations provided by the ECG core lab. Three replicate Holter ECGs were collected at 30, 15, and 0 minutes prior to the administration of study treatment on Days 1 (Baseline for placebo) and 3 (Baseline for lapatinib) and pre-dose and 1, 2, 3, 4, 6, 8, 10, and 24 hours post dose on Days 2 and 4. The three readings at each time point were averaged prior to any analysis. Baseline is the pre-dose ECGs (triplicate) taken on Day 1 for placebo and Day 3 for lapatinib. The number of participants with the worst-case post-Baseline 12-lead Holter ECG findings with significant ST, T wave, and U wave abnormalities were analyzed.

Pharmacodynamic (PD) Population: all participants from the All Treated Subjects Population (ATS) who completed the ECG acquisition via Holter monitoring of at least one time point on Days 1, 2, 3 and 4.

An AE is defined as any untoward medical occurrence in a participant temporally associated with the use of a medicinal product, whether or not considered related to the 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 or is a congenital anomaly/birth defect, or is an important medical eventsthat jeopardizes the participant or may require medical or surgical intervention to prevent one of the other outcomes listed in the above definition, new primary cancers, liver events, cardiac dysfunction, pneumonitis, and laboratory abnormalities.

ATS Population

Blood samples were collected for the measurement of albumin and hemoglobin at Baseline; Days 5 and 8-11. Baseline is defined as the most recent, non-missing value from a central laboratory prior to or on the first study treatment dose date.

ATS Population. Only participants available at the specified time point (represented as n=X in the category title) were analyzed.

Blood samples were collected for the measurement of ALP, ALT, and AST at Baseline; Days 5 and 8-11. Baseline is defined as the most recent, non-missing value from a central laboratory prior to or on the first study treatment dose date.

ATS Population. Only participants available at the specified time point (represented as n=X in the category title) were analyzed.

Blood samples were collected for the measurement of direct bilirubin, total bilirubin, and creatinine at Baseline; Days 5 and 8-11; Baseline is defined as the most recent, non-missing value from a central laboratory prior to or on the first study treatment dose date.

ATS Population. Only participants available at the specified time point (represented as n=X in the category title) were analyzed.

Blood samples were collected for the measurement of calcium, chloride, CO2, potassium, sodium, magnesium and urea at Baseline; at Days 5 and 8-11. Baseline is defined as the most recent, non-missing value from a central laboratory prior to or on the first study treatment dose date.

ATS Population. Only participants available at the specified time point (represented as n=X in the category title) were analyzed.

Blood samples were collected for the measurement of total neutrophils (ANC), platelets, and leukocyte count at Baseline; Days 5 and 8-11. Baseline was defined as the most recent, non-missing value from a central laboratory prior to or on the first study treatment dose date.

ATS Population. Only participants available at the specified time point (represented as n=X in the category title) were analyzed.

Blood pressure measurements included SBP and DBP and were obtained at Baseline; on Day 2 (at pre-dose, 4, 8, 12 and 24 hours post dose), and on Day 4 (at pre-dose, 4, 8, 12 and 24 hours post dose). Baseline is defined as the most recent, non-missing value prior to or on the first study treatment dose date. Change from Baseline was calculated as the post-Baseline value minus the Baseline value.

ATS Population. Only participants available at the specified time point (represented as n=X in the category title) were analyzed.

Heart rate were measured at Baseline; on Day 2 (at pre-dose, 4, 8, 12 and 24 hours post dose), and on Day 4 (at pre-dose, 4, 8, 12 and 24 hours post dose. Baseline is defined as the most recent, non-missing value prior to or on the first study treatment dose date. Change from Baseline was calculated as the post-Baseline value minus the Baseline value.

ATS Population. Only participants available at the specified time point (represented as n=X in the category title) were analyzed.

The number of participants with the 12-lead ECG findings normal (NL), abnormal not clinically significant (Abn NCS), and abnormal clinically significant (Abn CS) are reported. Clinical significance was based on the medical and scientific judgement of the investigator or qualified designee. A single safety 12-lead ECG was performed using a standard 12-lead ECG machine at Baseline; on Day 1 (at pre-dose); on Day 2 (at pre-dose, 4, 8, 12 and 24 hours post-last- dose); on Day 4 (at pre-dose, 4, 8, 12 and 24 hours post-last-dose); at the End of Study visit (Day 8-11); and at the post-treatment Follow-up visit (if applicable).

ATS Population. Only participants available at the specified time point (represented as n=X in the category title) were analyzed.

AUC is defined as the area under the lapatinib concentration-time curve as a measure of drug exposure. AUC(0-t) and AUC(0-24) were determined from the plasma concentration-time data using the linear trapezoidal rule for increased concentrations and the logarithmic trapezoidal rule for decreased concentrations. For PK analysis, one blood sample was collected on Day 1 for placebo Baseline. The 24 hour blood sample on Day 2 also served for lapatinib Baseline. Pre-dose blood samples were collected 30 minutes prior to the administration of study medication on Day 2 (placebo) and Day 4 (lapatinib). Serial blood samples were collected on Day 2 (for placebo) and on Day 4 (for lapatinib) at the following post-last-dose time points 1, 2, 3, 4, 6, 8, 10, 12, and 24 hours.

Pharmacokinetic (PK) Population: all participants in the ATS Population for whom at least one PK sample was obtained and analyzed. Only participants available at the specified time point (represented as n=X in the category title) were analyzed.

The first occurrence of Cmax and C24 was determined directly from the raw concentration-time data. For PK analysis, one blood sample was collected on Day 1 for placebo Baseline. The 24 hour blood sample on Day 2 also served for lapatinib Baseline. Pre-dose blood samples were collected 30 minutes prior to the administration of study medication on Day 2 (placebo) and Day 4 (lapatinib). Serial blood samples were collected on Day 2 (for placebo) and on Day 4 (for lapatinib) at the following post-last-dose time points 1, 2, 3, 4, 6, 8, 10, 12, and 24 hours.

PK Population

For each participant, the time at which Cmax was observed (tmax) was determined directly from the raw concentration-time data. For each participant, the time prior to the first quantifiable (non-zero) concentration (tlag) was determined directly from the raw concentration-time data. Since all participants received 2 doses of study medication prior to the collection of the first (pre-dose) blood sample on Day 4, tlag was expected to be zero. For PK analysis, one blood sample was collected on Day 1 for placebo Baseline. The 24 hour blood sample on Day 2 also served for lapatinib Baseline. Pre-dose blood samples were collected 30 minutes prior to the administration of study medication on Day 2 (placebo) and Day 4 (lapatinib). Serial blood samples were collected on Day 2 (for placebo) and on Day 4 (for lapatinib) at the following post-last-dose time points 1, 2, 3, 4, 6, 8, 10, 12, and 24 hours.

PK Population

Participants received three doses of lapatinib 2000 mg (250 mg x 8 tablets/dose) in the morning and evening on Day 3 and in the morning on Day 4.