Additional Study Information: The purpose of this research study is to learn about the safety and effectiveness of the study drug, PF-06650808, when given as a single agent and to find the best dose for treating cancer. Prior to this study, PF-06650808 has never been given to people. PF-06650808 is known as an antibody drug conjugate. A toxic agent is chemically linked to an antibody. The antibody selectively binds to a protein, in this case NOTCH3, found on certain cancer cells. This allows delivery of a toxic agent directly to cancer cells, slowing their growth and causing them to die. It also minimizes the exposure of normal tissues to the toxic agent. Research has shown that NOTCH3 is present on a variety of human cancers. PF-06650808 is a new investigational drug being studied to treat patients with cancer. This research study will be the first time more than one dose of PF-06650808 will be given to people.