Trial of an Alternative Cabozantinib Dosing Schedule in Metastatic Renal Cell Carcinoma and Neuroendocrine Tumors

Inclusion Criteria * Cohorts A and B: Histologically or cytologically confirmed advanced RCC with any clear cell or non-clear cell component. 100% sarcomatoid is permissible. * Cohorts A and B: Patient may have had any number of prior therapies for Cohort A, but for Cohort B patients must not have received any systemic therapy in the metastatic setting * Patients who have received prior (neo)adjuvant immunotherapy with pembrolizumab or similar are eligible for Cohort B IF they completed the adjuvant therapy \> 12 months from start of trial therapy * Treatment naïve patients may be treated in Cohort A if deemed not candidates for nivolumab or if felt single agent cabozantinib most appropriate by the treating clinician * Cohort C: Well differentiated NET, grades 1-3 (any primary site) who have progressed on or are not eligible for somatostatin analogs per treating physician discretion * Cohort C: Disease progression within prior 12 months * Cohort C: Prior or concurrent treatment with somatostatin analogue allowed but no limit on lines of therapy (stable dose of somatostatin for 2 months) All Cohorts: * At least one measurable lesion as defined by RECIST version 1.1 * No evidence of pre-existing uncontrolled hypertension as assessed by investigator. Patients may undergo adjustments or additions to their antihypertensive regimen before or during screening to achieve optimal BP control. * Age \> 18 years. * ECOG performance status 0 - 2 * Patients must have normal organ …