PERCEPTION: Phase II investigational study of pembrolizumab combination with chemotherapy in platinum-sensitive recurrent low-grade serous ovarian cancer— A NOGGO trial.

Abstract

TPS5613 Background: Low-grade serous ovarian cancer (LGSOC) represents a minority within the group of invasive epithelial ovarian malignancies. Recent analyses showed a very limited responsiveness to chemotherapy in LGSOC. Since bevacizumab many years ago, none other agents have been approved in LGSOC. There is a high demand of new therapy combinations with modern substances to improve the response rate and prognosis in this group of patients. Immune check-point inhibitors provide a new possibility which showed to be effective in different malignant diseases as well as in selected ovarian cancer patients. In this study, the standard chemotherapy is going to be combined with pembrolizumab in recurrent LGSOC cases with therapy free interval (TFI) over 6 months after last platinum-based chemotherapy. To the authors knowledge no comparable studies have been performed or planned. If our trial should show pembrolizumab effectivity in LGSOC, it would be a signal and impulse for future clinical studies in this rare disease. Methods: PERCEPTION/NOGGO-ov44 (NCT04575961) clinical trial is a multi-center, single-arm phase 2 study to evaluate pembrolizumab therapy concomitant to platinum-based chemotherapy (carboplatin plus pegylated liposomal doxorubicin, carboplatin plus gemcitabine or carboplatin monotherapy) and as maintenance in recurrent low-grade serous ovarian cancer cases. LGSOC patients with progression or recurrence at least six months after most previous platinum-containing therapy and in good general performance (ECOG 0 or 1) are eligible to participate in this clinical trial. The primary objective is the 12 months progression free survival (PFS) rate. Secondary end-points include overall survival, response rate (RR), PFS and RR according to Ki67 expression levels, time to first subsequent therapy (TFST) and its response, safety and quality of life. The trial is planned according to Simon’s two-stage design with total sample size up to 33 patients. The null hypothesis is PFS-rate after 12 months of 20%. In the first phase 18 patients will be enrolled and if at least 5 patients show PFS after 12 months the study is going to be continued with an additional 15 patients. The trial is claimed successful, if at least 11 patients show PFS after 12 months. Assuming a true PFS-rate of 40%, this trial has 5% type I error rate and 80% power. Clinical trial information: NCT04575961.