NEOadjuvant Dendritic cell therapy added to first line standard of care in advanced epithelial Ovarian Cancer (NEODOC): protocol of a first-in-human, exploratory, single-centre phase I/II trial in the Netherlands.

INTRODUCTION: The currently available immunotherapies have failed to meet expectations in inducing durable responses in patients with advanced epithelial ovarian cancer (EOC). The low number of somatic missense mutations in EOC necessitates highly potent neoantigen-directed approaches. To this end, we have developed a novel dendritic cell (DC) product that consists of a specialised cross-presenting subset of DC, conventional DC type 1 (cDC1). METHODS AND ANALYSIS: We will conduct the NEODOC study, an investigator-initiated first-in-human phase I/II trial. This study will assess the immunogenicity, safety and feasibility of a cDC1-based, autologous tumour lysate-loaded, DC product. 10 patients with previously untreated advanced EOC (stage IIIb-c, IVa or stage IVb if only supradiaphragmatic or inguinal lymph nodes <1 cm) requiring neoadjuvant chemotherapy will receive DC therapy alongside standard-of-care carboplatin/paclitaxel chemotherapy and interval cytoreductive surgery. The primary endpoint is immune response, and the secondary endpoints are the safety and feasibility of the treatment as well as clinical efficacy. ETHICS AND DISSEMINATION: Ethical approval for this trial was granted by the Netherlands Central Committee on Research Involving Human Subjects. The results will be disseminated through publications in international, open-access scientific journals and presentations at scientific conferences. TRIAL REGISTRATION NUMBER: NCT05773859; EUCT number 2024-512353-24-01.