Tocilizumab in Children With ACP

This study will be conducted in two phases. The first phase (phase 0) will be looking at patients with new or recurrent/ progressed craniopharyngioma tumors. These patients will be given one dose of tocilizumab before they have SOC surgery of their tumor. The objective of this phase is to see if drug reaches the tumor. If phase 0 is favorable and shows that drug is penetrating the tumor, the second phase of the study (feasibility phase) will open. Both phases will remain open concurrently and patients will be able to enroll on the Phase 0 then "roll over" and enroll on the feasibility phase. During the feasibility phase patients will be administered tocilizumab every two weeks for up to 13 cycles (approximately 1 year). Patients will be followed for up to 5 years in the feasibility phase.