OCEAN is a prospective, single-arm, interventional pilot study evaluating the feasibility and clinical utility of treatment selection guided by ex vivo drug sensitivity testing in patients with endocrine-resistant, hormone receptor-positive, HER2-negative or HER2-low metastatic breast cancer.
Fresh tumor tissue obtained through biopsy will be processed using an ex vivo organ culture (EVOC) platform. Tumor samples will be maintained in culture and exposed to a panel of anticancer agents to assess treatment-specific responses. Drug sensitivity results will be used to guide the selection of the next systemic anticancer treatment.
Participants will receive the selected treatment and undergo clinical and radiological assessments according to the study protocol.
The primary endpoint is objective response rate, defined as the proportion of participants achieving a complete or partial response. Secondary endpoints include progression-free survival, overall survival, clinical benefit rate, and the association between ex vivo drug sensitivity and clinical treatment outcomes.
The study aims to investigate whether functional testing of fresh tumor samples can support more individualized treatment selection after progression on endocrine therapy.
The study uses a Simon's two-stage design with an interim analysis after enrollment of the first 19 participants. Based on the prespecified response criteria, the study may stop after the first stage or proceed to enroll an additional 20 participants, for a maximum total enrollment of 39 participants.
