What this phase means
Phase 3: this treatment already looked useful in smaller studies. Now it is tested in a large group, often against standard care or a dummy treatment, to see if it should be approved.
Phase labels are FDA/ICH categories applied to the registry Phase field. They are not a finding that this study succeeded.
What the registry says happens
If you join, the listed intervention(s) are Trastuzumab deruxtecan, Trastuzumab, or Pertuzumab. The registry lists allocation as na. This study will evaluate a structured sequential treatment strategy starting with T-DXd + pertuzumab upfront therapy, followed by an optimized maintenance therapy with dual HER2+blockade + CDK4/6i + ET and the opportunity to retreat with T-DXd once patients progress under maintenance aimed to maximizing disease control, optimizing tolerability, and preserving T-DXd as a future therapeutic option, while ensuring participant safety and regulatory compliance in participants with HER2+/HR+ advanced/metastatic breast cancer.
They plan to enroll about 200 people at 5 sites. Taking part typically means taking a study drug (or dummy pill) plus check-ins.
Official title (unrewritten)
A Global, Interventional, Open-label Trial of T-DXd-based Therapy Followed by Palbociclib, Endocrine Therapy and Dual HER2 Blockade in First-line HER2+/ HR+ Advanced or Metastatic Breast Cancer and Retreatment With T-DXd (DB-Guide)
Interventions: Trastuzumab deruxtecan, Trastuzumab, Pertuzumab, Endocrine Therapy, Palbociclib
Primary outcome (registry wording): Progression-free Survival (PFS) Rate at 24 Months