Pembrolizumab and Lenvatinib for Platinum- Sensitive Recurrent Ovarian Cancer

This will be a phase-2, open-label, single-arm, single-center study to assess the effect of pembrolizumab and Lenvatinib combination therapy on platinum-sensitive recurrent ovarian cancer (ROC) patients. Female patients 18 years of age or older with histologically-confirmed epithelial ovarian cancer (EOC) - excluding low grade tumors and mucinous histology - and documented disease recurrence following primary or interval debulking surgery and 1-2 prior lines of chemotherapy (including a frontline platinum-based regimen) and a platinum-free interval greater than 6 months will be eligible to enroll in the study. Twenty-four patients will be included in the study. The study diagram is shown in Figure 1 and the schedule of assessments (SoA) is shown in Section 6.0. After signing the informed consent, eligible subjects according to the inclusion and exclusion criteria will receive oral Lenvatinib 20 mg once daily (QD) plus intravenous (IV) pembrolizumab 200 mg every three weeks (Q3W) until evident progressive disease by CT (RECIST), or unacceptable toxicity, or until completion of 35 treatment cycles with pembrolizumab. Disease status will be evaluated radiologically by computed tomography (CT) every 9 weeks, in comparison to pretreatment CT, until progression. In case of study withdrawal due to other reasons, radiological evaluation will be maintained every 9 weeks until disease progression or patient's withdrawal of consent or a new anticancer regimen is given. Patients with contrast media allergy will undergo chest CT without contrast medium as well as abdominal and pelvic magnetic resonance imaging (MRI). Toxicity will be graded by the National Cancer Institute Common Terminology Criteria for Adverse Events Ver. 5.0 (NCI-CTCAE). Dose reductions and modification of Lenvatinib will be performed according to the indications in Section 5.2.3. Pembrolizumab dose will not be reduced but the dose can be delayed for up to 9 weeks in case of toxicity which requires steroid. treatment and steroids withdrawal (refer to Section 5.2.2 on pembrolizumab dose interruptions). Refer to section 5.2.4 for dose modifications for overlapping toxicities. Health-related quality of life will also be evaluated. Collateral research will focus on potential biomarkers of response to treatment and on micro- and macro-environmental changes occurring during the course of treatment. To that end, tumor biopsies, stool and vaginal swabs and blood (plasma, serum and peripheral blood mononuclear cells (PBMC)) samples will be collected at Screening and during the study. Analyses will be performed to determine pre- and post-treatment changes as well as differences between responders to treatment and non-responders. Participants who stop study treatment after receiving 35 administrations of pembrolizumab for reasons other than disease progression or intolerability, or participants who attain a complete response (CR) and stop study treatment may be eligible for up to 1 year of treatment with pembrolizumab (17 cycles) ± Lenvatinib upon experiencing disease progression (Second Course Phase). Participants who complete treatment with pembrolizumab after 35 cycles (approximately 2 years) or CR will continue to receive Lenvatinib alone until disease progression, development of unacceptable toxicity, or withdrawal of consent.