A Phase 3 clinical trial evaluating Trastuzumab Deruxtecan (Enhertu) for non-luminal A, ER-positive/HER2-low metastatic breast cancer was officially withdrawn as of 2026-01-01. The trial, NCT06585969, had no participant enrollment prior to its withdrawal.
Background
Trastuzumab Deruxtecan is an antibody-drug conjugate. The withdrawn trial aimed to investigate its use in patients with metastatic breast cancer that is ER-positive and HER2-low, specifically in non-luminal A subtypes such as Luminal B, HER2-enriched, and Basal-like breast cancers. Metastatic breast cancer represents an advanced stage of the disease where cancer cells have spread to distant parts of the body.
Trial design
The trial, identified as DBCG R25 (NCT06585969), was designed as a Phase 3, randomized study. It intended to compare Trastuzumab Deruxtecan (t-dxd) against standard of care, which included ribociclib with et and abemaciclib with et. The study's objective was to evaluate the effect on progression-free survival (PFS) in the first-line setting for patients with non-Luminal A, ER-positive/HER2-negative metastatic breast cancer. However, the trial was withdrawn prior to enrolling any participants, with an enrollment count of 0.
What this means
The withdrawal of this Phase 3 trial for Trastuzumab Deruxtecan means that the planned comparison against CDK4/6 inhibitors in non-luminal A, ER-positive/HER2-low metastatic breast cancer will not proceed as originally intended. With no participants enrolled, no data on progression-free survival or other outcomes from this specific study will become available. This outcome indicates a change in the development pathway or strategy for Trastuzumab Deruxtecan in this particular patient population and treatment line.
Source
The information regarding the withdrawal of trial NCT06585969 was obtained from ClinicalTrials.gov, a public database of clinical studies. The update, including the trial's withdrawn status and primary completion date, was recorded on 2026-01-01 on clinicaltrials.gov.