NCT04965766

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

Phase 2, Open Label Study of Patritumab Deruxtecan (U3-1402), an Anti-HER3-Antibody Drug Conjugate (ADC), in Patients With Advanced Breast Cancer, With Biomarker Analyses to Characterize Response to Therapy

• Status: Recruiting
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 139 (estimated)
• Sponsor: Gustave Roussy, Cancer Campus, Grand Paris · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

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.

Conditions

• Metastatic Breast Cancer
• Advanced Breast Cancer

Interventions

Type	Name	Description
DRUG	U3-1402	U3-1402 is uniquely designed to target HER3-a receptor that contributes to treatment resistance and poor prognosis in hormone receptor-positive, HER2-negative (HR+/HER2-) breast cancer patients. This drug is distinct from other interventions due to its composition as an antibody-drug conjugate (ADC): a monoclonal antibody against HER3 conjugated to a topoisomerase I inhibitor, which specifically targets HER3-overexpressing tumor cells. The drug is delivered via a cleavable linker that allows for controlled release of the chemotherapeutic agent within the cancer cells, minimizing systemic side effects.

Timeline

• Start date: 2021-05-11
• Primary completion: 2027-04-11
• Completion: 2030-04-11
• First posted: 2021-07-16
• Last updated: 2025-12-23

Locations

11 sites across 1 country: France