What this phase means
Phase 2: researchers already know a roughly safe dose (from phase 1). This stage asks whether the treatment actually helps the condition, and watches side effects more closely.
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 Patritumab deruxtecan, Trastuzumab, or Trastuzumab Biosimilar. The registry lists allocation as randomized. Researchers want to learn if patritumab deruxtecan (MK-1022) can treat certain breast cancers.
They plan to enroll about 181 people at 18 sites. Taking part typically means an infusion or injection of a biologic plus check-ins.
Official title (unrewritten)
HERTHENA-Breast-01: A Phase 1b/2, Multicenter, Open-label, Dose-Finding Study to Evaluate the Safety and Antitumor Activity of Patritumab Deruxtecan in Participants With HER2 Positive Unresectable Locally Advanced Breast Cancer or Metastatic Breast Cancer
Interventions: Patritumab deruxtecan, Trastuzumab, Trastuzumab Biosimilar, Pertuzumab, Tucatinib
Primary outcome (registry wording): Part 1: Number of Participants Experiencing Dose-Limiting Toxicity (DLT)