Patritumab Deruxtecan (U3-1402) in Unresectable Locally Advanced or Metastatic Breast Cancer

⚠️

This is not medical advice. AI-assisted translation — inaccuracies may occur. Always verify the original and consult your oncologist before taking any steps.

About the trial

This study aims to evaluate the efficacy and safety of U3-1402 in participants with advanced breast cancer (ABC). Participants have to be hormone-receptor positive (HR+) and have to be resistant to endocrine therapy and cyclin-dependent kinases 4 and 6 (CDK4/6) inhibitors. Participants may have received multiple lines of endocrine therapy with or without targeted therapies and must have received only one line of chemotherapy for ABC. Moreover, the immune effects, the predictors of resistance and response to treatment, the effect of the chemotherapy on deoxyribonucleic acid (DNA) replication will be assessed and will help identify the subgroups that will mostly benefit from the treatment. The pharmacokinetics of the product and the anti-drug antibody (ADA) will be also evaluated. A total of 99 participants are planned to be treated in the study. Participants will receive, every three weeks, a dose of U3-1402 equivalent to 5.6 mg/kg of body weight until progression or until unacceptable toxicity. Tumor evaluation will be performed every six weeks by the mean of a computed tomography for the thorax, abdomen and pelvis (TAP CT-scan) or a magnetic resonance imaging (MRI). Brain and/or bone CT scans will be also performed throughout the study for participants with brain and/or bone metastasis. A PET scan combined with contrast enhanced CT scan can replace all the above-mentioned imaging if performed at baseline considering that the same imaging technique should be used throughout the study. The safety of the product will be assessed at each cycle, through complete clinical exams, biological tests, electrocardiograms (ECGs), cardiac echographies (ECHOs) and through the collection of ongoing toxicities or adverse events.

Original English text from ClinicalTrials.gov

Who can (and can't) join

✓ Qualifies

  • Pacjentki z zaawansowanym lub rozsianym rakiem piersi, który jest dodatni na receptory hormonalne (HR+).
  • Rak piersi, który stał się oporny na leczenie hormonalne i inhibitory CDK4/6.
  • Pacjentki, które otrzymały co najmniej jedną linię chemioterapii z powodu zaawansowanego raka piersi.
  • Pacjentki z guzem, który można łatwo pobrać do biopsji (z wyjątkiem przerzutów do kości).
  • Pacjentki z guzem, który można zmierzyć na badaniach obrazowych.
  • Pacjentki w dobrym stanie ogólnym (ECOG 0-1) i z przewidywaną długością życia powyżej 12 tygodni.
  • Kobiety w wieku rozrodczym muszą stosować skuteczną antykoncepcję.

✗ Disqualifies

  • Pacjentki z HER2-ujemnym rakiem piersi, który nie jest oporny na leczenie.
  • Pacjentki, które otrzymały więcej niż jedną linię chemioterapii z powodu zaawansowanego raka piersi.
  • Pacjentki z guzem niemożliwym do zbadania lub zmierzenia.
  • Pacjentki z poważnymi chorobami serca, wątroby lub nerek.
  • Kobiety w ciąży lub karmiące piersią.

Simplified criteria — AI translation

Trial details

Minimum age
18 Years
Last updated (source)
December 23, 2025
Sex
No restrictions

Therapies / drugs in trial

Locations (11)

Centre Georges François Leclerc

Dijon, France

CHU de Limoges

Limoges, France

Centre Léon Bérard

Lyon, France

Institut Paoli Calmettes

Marseille, France

Institut Régional du Cancer de Montpellier

Montpellier, France

Centre Antoine Lacassagne

Nice, France

Institut Curie

Paris, France

Hôpital Tenon

Paris, France

Institut de Cancérologie de l'Ouest

Saint-Herblain, France

Institut Claudius Regaud

Toulouse, France

Gustave Roussy

Villejuif, France

Trial contact

Contact information from ClinicalTrials.gov. Contact in English.

Share this trial

Data from ClinicalTrials.gov. AI-assisted translation, last sync: 7/1/2026.

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