Primary Objectives:
Primary Objective: To determine the intracranial PFS of pembrolizumab plus lenvatinib in IO refractory mRCC participants with brain metastases per Response Assessment in Neuro-Oncology-Brain Metastases (RANO-BM) criteria (Appendix 1).
Hypothesis: Investigators hypothesize that pembrolizumab plus lenvatinib will provide a higher intracranial PFS in RCC participants with brain metastases when compared to historical data.
Primary Endpoint: intracranial PFS per RANO-BM criteria.
Secondary Objectives:
* To determine the intracranial ORR in participants with remaining non-irradiated brain metastases, as assessed by RANO-BM criteria.
* To determine the local control rate in participants with irradiated brain metastases at 1 year, as assessed by RANO-BM criteria.
* To determine the rate of new brain metastasis at a site different from the original brain metastases at 1 year (Distant brain failure rate), as assessed by RANO-BM criteria.
* To determine the intracranial disease control rate: complete response + partial response + stable disease (DCR: CR + PR + SD) in participants with remaining non-irradiated brain metastases, as assessed by RANO-BM.
* To determine the intracranial clinical benefit rate (CBR: CR + PR + .6 months SD) in participants with remaining non-irradiated brain metastases, as assessed by RANO-BM.
* To determine the intracranial duration of response (DOR) in participants with remaining nonirradiated brain metastases, as assessed by the RANO-BM.
* To determine the time to response (TTR) in participants with remaining non-irradiated brain metastases, as assessed by the RANO-BM.
* To evaluate the safety and tolerability, as assessed by the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) v5.0 (Appendix 9).
* To define symptomatic radiation necrosis rate defined as the rate of clinical symptomatology requiring steroid administration and/or operative intervention concomitant with advanced and routine brain imaging findings consistent with radiation necrosis.
* To determine the extracranial ORR, as assessed by the Modified Response Evaluation Criteria in Solid Tumors v1.1 (RECIST 1.1).
* To determine extracranial PFS, as assessed by the RECIST 1.1 and iRECIST.
* To determine bi-compartmental PFS, as assessed by RECIST 1.1 and iRECIST for extracranial disease and RANO-BM for intracranial disease.
* To evaluate OS.
Secondary Endpoints:
* Intracranial OR in participants with remaining non-irradiated brain metastases, as assessed by RANO-BM criteria.
* Local control rate in participants with irradiated brain metastases at 1 year, as assessed by RANO-BM criteria.
* Distant brain failure rate, the rate of new brain metastasis at a site different from the original brain metastases at 1 year, as assessed by RANO-BM criteria.
* Intracranial disease contro (CR + PR + SD) in participants with remaining non-irradiated brain metastases, as assessed by RANO-BM.
* Intracranial clinical benefit (CR + PR + .6 months SD) in participants with remaining nonirradiated brain metastases, as assessed by RANO-BM.
* Intracranial duration of response (DOR) in participants with remaining non-irradiated brain metastases, as assessed by the RANO-BM.
* Time to response (TTR) in participants with remaining non-irradiated brain metastases, as assessed by the RANO-BM.
* Safety and tolerability, as assessed by the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) v5.0.
* Symptomatic radiation necrosis rate defined as the rate of clinical symptomatology requiring steroid administration and/or operative intervention concomitant with advanced and routine brain imaging findings consistent with radiation necrosis.
* Extracranial OR, as assessed by the RECIST 1.1 and iRECIST.
* Extracranial PFS, as assessed by the RECIST 1.1 and iRECIST.
* Bi-compartmental PFS, as assessed by RECIST 1.1 and iRECIST for extracranial disease and RANO-BM for intracranial disease.
* Overall survival (OS).