The primary purpose of this study is to assess the effectiveness of zanzalintinib compared to everolimus in participants with previously treated, unresectable, locally advanced or metastatic neuroendocrine tumors.

Substudy 03C is part of a larger research study that is testing experimental treatments for renal cell carcinoma (RCC). The larger study is the umbrella study (U03).

The goal of substudy 03C is to evaluate the safety and efficacy of experimental combinations of investigational agents in participants with clear cell renal cell carcinoma (ccRCC) who have recurrent disease during or after anti-programmed cell death 1/programmed cell death ligand 1 (PD-\[L\]1) adjuvant therapy.

This substudy will have two phases: a safety lead-in phase and an efficacy phase. The safety lead-in phase will be used to demonstrate a tolerable safety profile for the combination of investigational agents. There will be no hypothesis testing in this study