If you are found to be eligible to take part in this study, you will receive nivolumab by vein over about 1 hour on Days 1 and 15 of each cycle. After Cycle 6, you may receive nivolumab 1 time each month. After you have been on study for about 1 year, you may receive the study drug 1 time every 3 months. If during this time, the disease appears to get worse, you may go back to receiving the study drug on Days 1 and 15 of each cycle. The study doctor will discuss this with you.