Testing a new antibody treatment against advanced breast cancer

Plain-English translation of NCT06846437 on ClinicalTrials.gov ↗ · Source last updated March 2025 · Translation generated July 2026 · How we translate trials

Phase 3 — Testing in thousands of people, comparing the treatment against what doctors currently use. This is the last big step before approval.

What is this trial?

This trial is testing whether a new medication called works better and is safer than an existing treatment (trastuzumab emtansine) for people with advanced breast cancer. Both medications are antibody-based drugs designed to target cancer cells that have a specific protein called HER2. You would receive one of these two treatments every 3 weeks as an intravenous infusion (through a vein).

Many people with HER2-positive advanced breast cancer eventually stop responding to standard treatments like trastuzumab. This trial exists to see if this new medication can help patients whose cancer has grown or returned despite previous therapy.

Do you qualify?

You likely qualify if…

you are 18 years or older
you have been diagnosed with advanced (locally advanced or metastatic) breast cancer that cannot be surgically removed
your cancer tests positive for the HER2 protein
you have previously received trastuzumab (or a similar biosimilar) and a chemotherapy called taxane, and your cancer has progressed
you have adequate organ and bone marrow function and are well enough to tolerate treatment (ECOG score 0–1)
you are expected to survive for at least 3 months

You likely don't qualify if…

you have previously received other antibody-based drugs similar to this one (especially those containing DM1)
you have had another cancer diagnosis within the past 3 years
you have untreated or unstable brain or spinal cord metastases (cancer spread to the brain or spine)
you have a history of heart failure or significantly reduced heart function during previous HER2-targeted therapy
you have received other cancer treatments (chemotherapy, immunotherapy, or other targeted drugs) within the past 2–4 weeks

What participation looks like

You will be randomly assigned to receive either or the standard treatment (trastuzumab emtansine). You will visit the clinic every 3 weeks to receive your medication as an intravenous infusion. You will continue treatment as long as your cancer is controlled and you are tolerating the medication well. The trial staff will monitor you regularly with blood tests and scans to watch for how well the treatment is working and to check for any side effects.

AI-generated summary from trial data · Jul 18, 2026 · Not medical advice

Trial locations(1 site)

China

Fudan University Shanghai Cancer Center, Shanghai