Pembrolizumab and Lenvatinib in Clear Cell Ovarian Cancer

Inclusion Criteria: * Participants must have histologically or cytologically confirmed recurrent or persistent clear cell carcinoma of the ovary (CCOC) (≥50% clear cell histology). * Participants must have measurable disease, defined as at least one lesion that can be accurately measured per RECIST v1.1 criteria. Lesions situated in a previously irradiated area are considered measurable if progression has been demonstrated in such lesions. * Participants must have received at least one prior platinum-based chemotherapeutic regimen for primary management of disease. * Prior bevacizumab is allowed. * Prior use of immune checkpoint inhibitors (e.g. anti-PD-1, anti-PD-L1, anti-CTLA-4) is allowed for up to 30% of participants. * Unlimited prior lines for the treatment of recurrent or persistent disease are allowed. * Age ≥18 years. Because no dosing or adverse event data are currently available on the use of the combination of pembrolizumab/lenvatinib in participants \<18 years of age, children are excluded from this study. * ECOG performance status of 0 or 1 (Karnofsky performance scale ≥70%). * Participants must have adequate organ and marrow function as defined below: * absolute neutrophil count ≥1,500/μcL * hemoglobin ≥ 9g/dL (without use of erythropoietin; without packed RBC transfusion within preceding 2 weeks) * platelet count ≥100,000/μcL * total bilirubin ≤ institutional upper limit of normal (ULN) (in the absence of liver metastases) or ≤ 1.5 × institutional UL…