If found to be eligible to take part in this study, they will be assigned to a dose level of utomilumab based on when they join study. Up to 3 dose levels of utomilumab will be tested. The first group of participants will receive the lowest dose level. Each new group will receive a higher dose than the group before it, if no intolerable side effects were seen. This will continue until the highest tolerable dose of utomilumab is found.