Abstract 5917: A novel ROR1 antibody with high specificity and sensitivity for predictive biomarker detection in various tumor types

Abstract ROR1, a receptor tyrosine kinase-like orphan receptor, is a key mediator of non-canonical Wnt signaling and plays a critical role in cancer progression. ROR1 is selectively and highly expressed in various solid tumors and hematological malignancies while absent in normal adult tissues, making it a promising target for cancer therapy. Despite this potential, the lack of effective tools has hindered sensitive detection of ROR1 in patient tumor samples by IHC. To address this, we have developed a recombinant rabbit monoclonal antibody in-house, demonstrating superior sensitivity and specificity across multiple methodologies compared to existing antibodies. Additionally, we have established standardized interpretation criteria and performed an extensive epidemiological survey across ROR1-associated cancer types, reporting the following detection rates: 45% in pancreatic cancer (n=40), 39% in ovarian cancer (n=150), 48% in lung adenocarcinoma (n=140), 15% in endometrial cancer (n=97), 18% in triple-negative breast cancer (n=110), 23% in mesothelioma (n=47), and 10% in esophageal squamous carcinoma (n=70). These results validate this antibody as a reliable tool for clinical biomarker detection, potentially advancing ROR1-targeted cancer treatment. Citation Format: Xin Zhang, Qianqian Lian, Qian Qian, Dan Lu, Yanling Liu, Ying Tong, Qingyang Gu. A novel ROR1 antibody with high specificity and sensitivity for predictive biomarker detection in various tumor types [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 5917.