Abstract OT3-18-01: Detect III/IV study trial - The multicenter study program in patients with HER2-negative MBC and circulating tumor cells

Background: The collaborative DETECT study program represents a large program on metastatic breast cancer (MBC) worldwide. The main objective of the DETECT trial is to evaluate the efficacy of individualized breast cancer treatment based on the presence and phenotype setting of circulating tumor cells (CTCs). Thus, the DETECT study program is one of the first clinical trials translating the role of CTC enumeration/phenotyping directly into treatment intervention within different breast cancer subtypes. Trial design: The DETECT-III trial is a multicenter, randomized, phase III study comparing standard therapy alone versus standard therapy plus lapatinib in patients with initially HER2-negative MBC and HER2-positive CTCs. Patients with HER2-negative MBC and only HER2-negative CTCs can be included within the DETECT-IV trial, a prospective, multicenter, open-label, phase II study including patients with HER2-negative MBC. Within the DETECT-IV study setting postmenopausal patients with hormone-receptor positive MBC are treated with the CDK 4/6 inhibitor ribociclib and endocrine therapy, while women with triple negative MBC or a hormone-receptor positive tumor and indication for chemotherapy will receive eribulin. Specific aims: The DETECT study program offers various up-to-date treatment options, generating a wealth of clinical data including long-term follow-up data, evaluated in the controlled setting of a single large clinical trial program. The primary endpoint of the DETECT III trial is the comparison of efficacy as assessed using CTC clearance rate between patients receiving standard anticancer therapy with lapatinib and patients receiving standard anticancer therapy alone. The secondary objective of this trial is to assess the level of compliance to study procedures comparing the efficacy of lapatinib between given treatment groups. The primary objectives of the DETECT- IV trial are to evaluate CTC clearance rate for the ribociclib cohort and progression-free survival (defined as time interval from date of recruitment until progressive disease) for the eribulin cohort. The main focal point of the extensive collaborative translational oncology research projects is to apply innovative biomarkers and assays focusing on molecular characteristics of CTCs. This “biological status” of CTCs may provide new information about their potential function in terms of a repeatedly performed liquid biopsy to assess the patients’ response to therapy. Citation Format: Sabrina Krause, Thomas WP Friedl, Peter A Fasching, Andreas Schneeweiss, Volkmar Muller, Sabine Riethdorf, Klaus Pantel, Florin-Andrei Taran, Arkadius Polasik, Marie Tzschaschel, Amelie de Gregorio, Franziska Meier-Stiegen, Jens Huober, Wolfgang Janni, Tanja Fehm. Detect III/IV study trial - The multicenter study program in patients with HER2-negative MBC and circulating tumor cells [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr OT3-18-01.