A Study in Cancer Patients to Evaluate the Effect of Lapatinib on the QTc Interval

Inclusion Criteria:

* Histologically or cytologically confirmed diagnosis of: Metastatic breast cancer that over-expresses ErbB2 OR Recurrent, advanced, or metastatic solid tumor malignancy (including breast cancer that does not over-express ErbB2) that is refractory to standard therapies, for which there is no approved therapy, or for which lapatinib in combination with one of the permitted anti-cancer regimens specified in the continuation study EGF111767 may provide clinical benefit.
* A female subject must be of non-childbearing potential or willing to use acceptable contraception.
* A male subject with a female partner of childbearing potential must agree to use acceptable contraception.
* Is able to swallow and retain oral medication and does not have uncontrolled emesis.
* ECOG performance status 0 to 1.
* Adequate bone marrow function: ANC (absolute neutrophil count) \>/=1.5 x 10\^9/L, Hemoglobin \>/=9 g/dL, Platelets \>/=75 x 10\^9/L.
* Albumin \>/=3 g/dL.
* Serum bilirubin \</=1.5 x ULN.
* AST and ALT \</=3 x ULN .
* Serum Creatinine \</=1.5 mg/dL or Calculated Creatinine Clearance \>/= 50 mL/min.
* Serum potassium and magnesium levels within normal limits.
* Has a LVEF within the normal institutional range (or \>/=50%).

Exclusion Criteria:

* Any of the following ECG findings: QTcF interval \>480 msec, PR interval \>240 msec or \</=110 msec, Bradycardia defined as sinus rate \<50 beats per minute.
* Cardiac conduction abnormalities denoted by any of the following: Evidence of second-degree (type II) or third-degree atrioventricular block, Evidence of ventricular pre-excitation, Electrocardiographic evidence of complete left bundle branch block (LBBB), Intraventricular conduction delay with QRS duration \>120 msec, Atrial fibrillation, Presence of cardiac pacemaker.
* History of any one of the following cardiovascular conditions within the past 6 months: Class III or IV congestive heart failure as defined by the New York Heart Association (NYHA), cardiac angioplasty or stenting, myocardial infarction, unstable angina, symptomatic peripheral vascular disease or other clinically significant cardiac disease.
* Personal history of long-QT syndrome.
* Is pregnant or lactating.
* Has malabsorption syndrome, or has undergone a resection or bypass of the distal stomach and pylorus, or small bowel.
* Has acute or currently active/requiring anti-viral therapy hepatic or biliary disease (with the exception of subjects with Gilbert's syndrome, asymptomatic gallstones, liver metastases or stable chronic liver disease per investigator assessment).
* Has evidence of symptomatic or uncontrolled brain metastases or leptomeningeal disease. Subjects with brain metastases treated by surgery and/or radiotherapy are eligible if neurologically stable and do not require steroids or anticonvulsants for at least 28 days prior to the first dose of study drug.
* Has known immediate or delayed hypersensitivity reaction or idiosyncratic reaction to drugs chemically related to the investigational product.
* Has received anti-cancer therapy (including chemotherapy, radiation therapy, immunotherapy, biologic therapy, investigational therapy, surgery, or hormonal therapy) within 14 days prior to the first dose of study medication.
* Is receiving any prohibited medication or consuming any food or beverage within the timeframe indicated on the prohibited medication list in the protocol.