Additional Study Information: The purpose of this study is to find answers to the following research questions: 1. What is the highest dose of TTX-030 that can be given to subjects when given as an intravenous (IV through a needle into your vein) over a 30 minute period once every 3 weeks (for Arms 1-3) or once every 2 weeks (for Arm 4)? 2. What are the side effects of TTX-030 when given alone or in combination with either of the commercially approved agents? 3. How much TTX-030 is in the blood at specific times after dosing and how does the body get rid of the TTX-030? TTX-030 is a drug that impacts a pathway on the surface of cells called the adenosine pathway, by inhibiting a receptor called CD39. Cancer cells use this pathway as an important way to suppress the bodys immune system response and create and maintain a positive tumor environment. TTX-030 changes the pathway and promotes your bodys anti-tumor immune system response. TTX-030 has slowed the growth and/or shrank several types of cancers in animals. It is hoped that by taking TTX-030 the growth of your tumor will be slowed or will shrink, but TTX-030 has never been tested in humans. Although animal studies suggest that it may be helpful in humans, its effectiveness is not known. Cancers may include: bladder cancer, breast cancer, lung cancer, stomach cancer, colon cancer, rectal cancer, head and neck cancer, oral cancer, liver cancer, and melanoma.