Residual Disease

This is a Phase II, interventional, prospective, single-arm, multi-center study that will enroll patients with stage II/III triple negative breast cancer (TNBC) who have residual cancer burden (RCB) II/III after conventional neoadjuvant chemo-immunotherapy followed by surgery. Technological advances in ctDNA assays have improved both the sensitivity and reliability of molecular residual disease (MRD) detection to enable real-time measurement with clinical-grade assays. The primary objective of this study will be to evaluate ctDNA-based MRD status in high-risk, early-stage TNBC patients by defining the proportion of TNBC patients with MRD-only recurrence (ctDNA positive without radiographically measurable recurrence) during post-surgery surveillance. The secondary objectives will evaluate the safety, preliminary efficacy, and survival outcomes of using Dato-DXd in participants with MRD-only TNBC. Dato-DXd is an investigational antibody-drug conjugate (monoclonal antibody specific for TROP2 and a topoisomerase I (Topo-1) inhibitor) that has demonstrated promising efficacy in TNBC patients with a manageable safety profile.

There are two parts to this study. It is a phase 1b followed by a randomized phase 2 study to assess whether adding 3 years of adjuvant tetrathiomolybdate (TM) to standard 6 months treatment of adjuvant capecitabine and pembrolizumab in high risk for relapse triple negative breast cancer. In the phase 1b part of the study, TM is added to adjuvant capecitabine and pembrolizumab in high risk for relapse triple negative breast cancer (RCB 2, 3, risk for relapse \>60% at 5 years) after completion of neoadjuvant chemo-immunotherapy and surgery to establish the safety of the combination. This will be followed by a randomized phase 2 clinical trial of adjuvant TM and capecitabine vs capecitabine alone. If pembrolizumab was administered in the neoadjuvant setting, it may be continued in the adjuvant setting per investigator discretion.