Patritumab Deruxtecan (U3-1402) in Unresectable Locally Advanced or Metastatic Breast Cancer
Status:
Recruiting
Trial end date:
2026-06-11
Target enrollment:
Participant gender:
Summary
This study aims to evaluate the efficacy and safety of U3-1402 in participants with advanced
breast cancer (ABC) and high expression of human epidermal growth factor Receptor 3 (HER3)
defined as 75 percent or more of tumor cell expressing HER3 (seen at 10x objective).
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 100 participants are planned to be included 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.
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.