The MTD evaluation was based on the dose-limiting toxicity (DLT) evaluable population. DLT is defined as any Grade 3 or higher treatment-related toxicity that occurred during the DLT evaluation period (defined as the time from the first dose of MEDI0639 to 21 days after the first dose), except for National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE) Grade 3 hypertension that could be controlled within 96 hours; Grade 3 symptomatic hypertension of greater than (\>) 180 millimetre of mercury (mm Hg) systolic or \>120 mm Hg diastolic or asymptomatic hypertension of \>200 mm Hg systolic or \>120 mm Hg diastolic was considered a DLT.

An adverse event (AE) is any unfavourable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a study drug, whether or not considered related to the study drug. Treatment-emergent AEs (TEAEs) were events present at baseline that worsened in intensity after administration of study drug or events absent at baseline that emerged after administration of study drug, for the period extending to 90 days after the last dose of study drug. The AEs were summarized using Medical Dictionary for Regulatory Activities (MedDRA) version 18.1.

A serious AE (SAE) is any AE that results in death (refers to an event, which risk of death at the time of the event; it does not refer to an event that may have led to death), is immediately life threatening, require (or prolong) inpatient hospitalization, results in persistent or significant disability/incapacity, is a congenital anomaly or birth defect, or is an important medical event that may jeopardize the participant or may require medical intervention to prevent one of the outcomes listed above. Treatment-emergent SAEs defined as SAEs present at baseline that worsened in intensity after administration of study drug or SAEs absent at baseline that emerged after administration of study drug. The SAEs were summarized using MedDRA version 18.1.

Laboratory evaluations of blood and urine samples were performed, including hematology (white blood cell \[WBC\] count with differential, red blood cell \[RBC\] count, hematocrit, hemoglobin, platelet count, mean corpuscular volume \[MCV\], and mean corpuscular hemoglobin concentration \[MCHC\]); serum chemistry (calcium, chloride, magnesium, potassium, sodium, bicarbonate, aspartate transaminase \[AST\], alanine transaminase \[ALT\], alkaline phosphatase, total bilirubin, liver function test, gamma glutamyl transferase \[GGT\], lactate dehydrogenase, uric acid, creatinine, blood urea nitrogen \[BUN\], glucose, albumin, total protein, triglycerides, cholesterol, and troponin); and routine urinalysis. The TEAEs related to laboratory evaluations in participants were reported.

Vital signs (temperature, blood pressure, pulse rate, and respiratory rate) were performed at baseline and throughout the study. The TEAEs related to vital signs in participants were reported.

ECG parameters included QT interval and corrected QT (QTc) interval. Electrocardiogram (ECG) parameters were assessed at baseline as well as throughout the study. All 12-lead ECGs performed during the study were obtained in triplicate. The TEAEs related to ECG evaluations in participants were reported.

Echocardiogram parameters included left ventricular ejection fraction (LVEF) and pulmonary arterial pressure (PAP). The TEAEs related to echocardiogram evaluations in participants were reported.