PHESGO Maintenance After T-DXd Induction for HER2+ Breast Cancer

This study, called DEMETHER, is for people with HER2-positive (a type of breast cancer that tests positive for a protein called human epidermal growth factor receptor 2) unresectable locally recurrent or metastatic breast cancer. It's looking at how well two medicines, Trastuzumab deruxtecan (T-DXd) and Phesgo, work together. You would first receive T-DXd, followed by Phesgo as a maintenance treatment. Researchers want to see how long people live without their cancer getting worse (1-year PFS rate) and how long they live overall (3-year OS rate). The study is looking for about 165 participants who are at least 18 years old and have HER2-positive breast cancer.

Study design
This is an international, multicenter, open-label, single-arm Phase II clinical trial planning to enroll 165 participants.
What's involved
You would receive T-DXd treatment for 6 cycles, followed by Phesgo treatment. Treatment continues until disease progression, death, discontinuation, or up to 3 years after T-DXd starts.
Compensation
Not stated in the trial record.
Follow-up
After stopping treatment, you will have a safety visit about 28 days later. Researchers will also track your overall survival for an average of 36 months.

AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.

NCT06172127

PHESGO Maintenance After T-DXd Short Induction for HER2+ Unresectable Locally Recurrent or Metastatic Breast Cancer

Active, Not Recruiting
PHASE2Ages 18+InterventionalTreatment
MedSIR
~165 participants
Updated 2026-04-29 on ClinicalTrials.gov
What's tested:Trastuzumab deruxtecanPhesgo 1,200 MG / 600 MG / 30,000 UNT Per 15 ML InjectionPhesgo 600 MG / 600 MG / 20,000 UNT in 10 mL Injection

At a glance

Recruiting sites
0 of 36 listed sites are recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
1-year PFS rate
Measured over Baseline up to 12 months
+1 more outcome measured
HER2-positive Breast Cancer
36 sites across 7 states
Spain22
Germany4
Italy4
France3
Massachusetts1
New York1
Sevilla1
  • Javier Cortés, MD, PhD · PRINCIPAL_INVESTIGATOR · Institute of Breast Cancer, Quirón Group, Barcelona (Spain)
  • Antonio Llombart-Cussac, MD · PRINCIPAL_INVESTIGATOR · Arnau de Vilanova Hospital, Valencia (Spain)
  • José M Pérez-García, MD · PRINCIPAL_INVESTIGATOR · International Breast Cancer Center (Spain)

This trial hasn't published a contact. View it on ClinicalTrials.gov

  • 1-year PFS rateBaseline up to 12 months

    To determine the rate of patients with absence of disease progression or death from any cause at 1 year after the treatment initiation with T-DXd followed by PHESGO, as determined locally by the investigator using RECIST v.1.1

  • 3-year OS rateThrough study completion, an average of 36 months

    To determine the rate of patients alive at 3 years after treatment initiation with T-DXd followed by PHESGO.