Dose-Escalation Study of GSK2126458

This study is a Phase I, first-time-in-human dose escalation study in subjects with refractory solid tumors or lymphoma. The primary objective of this study is to determine the recommended Phase II dose of GSK2126458 based on safety and tolerability, pharmacokinetics, pharmacodynamics and preliminary evidence of clinical activity. Secondary objectives are to characterize the pharmacokinetics of GSK2126458; and to explore relationships between GSK2126458 pharmacokinetics, pharmacodynamics, response prediction biomarkers and clinical endpoints. Subjects with solid tumors or lymphoma will initially receive oral GSK2126458 daily for 28 consecutive days in each 28 day cycle. Subjects may be dosed once or twice a day or may be dosed on an intermittent schedule depending on the safety, pharmacokinetic and pharmacodynamic results that become available as the study progresses. The starting dose will be 0.1 mg once a day. Expansion of some cohorts will be conducted to test tumor pharmacodynamics, further explore the toxicity profile and to look for preliminary evidence of activity in subjects with tumors with PIK3CA mutations. The recommended Phase II dose will be the lowest dose explored (at or below MTD) that maintains biologic activity with an acceptable tolerability profile.