An interventional study of cResponse Ex Vivo Organ Culture (EVOC) Drug Sensitivity Assay in Metastatic Breast Cancer and Hormon Receptor Positive Breast Cancer, sponsored by Tel-Aviv Sourasky Medical Center. Recruiting at 1 site in Israel. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-26.
Sponsored by Tel-Aviv Sourasky Medical Center · Not applicable, Interventional, and Treatment
This study evaluates whether testing fresh tumor samples outside the body can help guide treatment selection for patients with hormone receptor-positive, HER2-negative metastatic breast cancer that has progressed during endocrine therapy.
A biopsy sample from each participant will be tested using an ex vivo organ culture (EVOC) platform, which preserves the tumor tissue and allows researchers to assess its response to different anticancer treatments. The results will be used to help select the participant's next systemic treatment.
The main objective is to evaluate the proportion of patients whose cancer responds to treatment selected using this approach. The study will also assess how long the cancer remains controlled, overall survival, and the relationship between laboratory test results and clinical outcomes.
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.
12,820 studies on the registry are indexed under Breast Neoplasms; 2,920 are open to participants now.
This study's planned enrollment of 39 is below the median of 72 across 9,494 interventional studies indexed under Breast Neoplasms.
Browse Breast Neoplasms studies →Tel-Aviv Sourasky Medical Center is the lead sponsor of 553 studies on the registry; 50 are open to participants now.
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Exclusion Criteria:
Participants with endocrine-resistant metastatic breast cancer will undergo tumor biopsy and functional drug sensitivity testing using the cResponse ex vivo organ culture (EVOC) platform. The next systemic anticancer treatment will be selected based on the assay results, with preference for the highest-scoring clinically available treatment.
Diagnostic Test: cResponse Ex Vivo Organ Culture (EVOC) Drug Sensitivity Assay
Fresh tumor tissue obtained by biopsy will undergo functional drug sensitivity testing using the cResponse ex vivo organ culture (EVOC) platform. Tumor samples will be exposed to a panel of anticancer agents, and treatment-specific response scores will be generated. The assay results will guide selection of the next available systemic anticancer treatment.
Objective Response Rate (ORR)
The proportion of evaluable participants achieving a complete response (CR) or partial response (PR) according to RECIST version 1.1 following systemic anticancer treatment selected using the cResponse ex vivo organ culture (EVOC) drug sensitivity assay. The response rate will be calculated among participants with an assay result indicating sensitivity to at least one tested treatment, as specified in the study protocol. Tumor response will be assessed approximately every 8 weeks until disease progression or treatment discontinuation.
Time frame: From initiation of assay-guided treatment through study completion, an estimated average of 1 year.
Progression-Free Survival (PFS)
Progression-free survival (PFS) is defined as the time from initiation of assay-guided systemic anticancer treatment to the first documented disease progression according to RECIST version 1.1 or death from any cause, whichever occurs first. Disease progression will be assessed approximately every 8 weeks. Participants without documented progression or death will be censored at the date of their last adequate disease assessment.
Time frame: From initiation of assay-guided treatment through study completion, an estimated average of 1 year.
Overall Survival (OS)
Overall survival (OS) is defined as the time from initiation of assay-guided systemic anticancer treatment to death from any cause. Participants who are alive at the time of analysis will be censored at the date they were last known to be alive.
Time frame: From initiation of assay-guided treatment until death from any cause or end of follow-up, up to 24 months.
Clinical Benefit Rate (CBR)
Clinical benefit rate (CBR) is defined as the proportion of evaluable participants achieving complete response (CR), partial response (PR), or stable disease (SD) of the protocol-defined minimum duration, according to RECIST version 1.1, following assay-guided systemic anticancer treatment. Tumor response will be assessed approximately every 8 weeks until disease progression or treatment discontinuation.
Time frame: From initiation of assay-guided treatment through study completion, an estimated average of 1 year.
Correlation Between cResponse Drug Sensitivity Score and Clinical Tumor Response
Correlation between the quantitative drug sensitivity score (range: 1-100; unitless, with higher scores indicating greater predicted drug sensitivity), generated by the cResponse ex vivo organ culture (EVOC) assay using a proprietary algorithm, and observed clinical tumor response to the selected treatment, assessed according to RECIST version 1.1. Clinical response will be categorized as complete response (CR), partial response (PR), stable disease (SD), or progressive disease (PD). The correlation will be quantified using Spearman's rank correlation coefficient (range: -1 to +1; unitless).
Time frame: From assay testing through study completion, an estimated average of 1 year.
Second Progression-Free Survival (PFS2)
Second progression-free survival (PFS2) is defined as the time from initiation of assay-guided systemic anticancer treatment to the second documented disease progression, occurring during or after subsequent anticancer treatment, or death from any cause, whichever occurs first. Participants without a documented PFS2 event will be censored at the date of their last adequate disease assessment, according to the study protocol.
Time frame: From initiation of assay-guided treatment through study completion, an estimated average of 2 years.
Plan to share: No — Individual participant data will not be made publicly available. Study data will be maintained in accordance with institutional policies, participant confidentiality requirements, and applicable ethical and regulatory approvals. Aggregate study results may be published or presented in scientific publications and conferences.
No publications or documents are linked to this record.
Started Jun 2024 (actual). Primary completion is estimated for Dec 2028, 54 months after the start.
Of 2,272 non-industry interventional studies with no phase under Breast Neoplasms, half reached primary completion within 34 months of starting (the median), counting those still running; a quarter within 16 and three quarters within 69. This study's planned 54 months is above that.
Counting every sponsor, half of 2,345 studies reached it within 34 months; a quarter within 16 and three quarters within 69.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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