The purpose of this study is to evaluate the safety and effectiveness of the drug trametinib given alone and in combination with GSK2141795 in patients with advanced uveal melanoma (a cancer of the eye) that cannot be cured by surgery. Trametinib is approved for treating advanced melanoma; it has been assessed thoroughly in patients with melanoma of the skin, but it has not been evaluated as well in uveal melanoma. Trametinib works by blocking a protein involved in cancer growth called MEK.
GSK2141795 is an investigational drug designed to inhibit cancer growth by blocking the activity of a protein called AKT. Patients will be randomly assigned to receive trametinib alone or trametinib plus GSK2141795. Both drugs are taken orally (by mouth).