How T-DM1 delivers its payload inside a HER2-positive cancer cell.

How T-DM1 works

T-DM1 (ado-trastuzumab emtansine) links the HER2-binding antibody trastuzumab to DM1, a microtubule inhibitor. The communication challenge is showing how recognition at the cell surface connects to an effect inside the cell.

1. Recognize HER2. The antibody component binds HER2 on the cell surface.
2. Enter and process. Receptor-mediated uptake brings the conjugate into the cell. Lysosomal degradation releases DM1-containing catabolites.
3. Disrupt microtubules. DM1 binds tubulin, disrupting the microtubule network and causing cell-cycle arrest and apoptotic cell death.

This sequence follows section 12.1 of the KADCYLA prescribing information. It highlights payload delivery; the label also describes antibody-mediated effects.

For a physician education program, the useful question is not simply whether the drug binds HER2. It is what must happen after binding for the payload to act. The interactive experience lets a viewer pause at those transitions; the film gives a guided explanation.

HER2 recognition to microtubule disruption

Six panels trace the antibody–drug conjugate from HER2 binding through cellular uptake and lysosomal processing to microtubule disruption and cell-cycle arrest.

Tumor response in DESTINY-Breast03

The clinical-results figure compares confirmed complete and partial responses to T-DXd and T-DM1 in DESTINY-Breast03, with the trial design, randomized treatment groups and source notes.

The companion evidence brief also summarizes progression-free and overall survival in EMILIA and DESTINY-Breast03, with selected safety findings and the dates of each analysis.

Scientific sources and representation limits

The mechanism summary below the film is based on the primary sources linked here. The source notes describe how those references relate to the visuals.

• KADCYLA prescribing information: mechanism, clinical studies and safety
• HER2–trastuzumab Fab experimental structure, PDB 1N8Z
• DESTINY-Breast03 original trial publication (Cortés et al., 2022)
• Figure sources and response-analysis context

The film follows selected delivery and cellular events. Its tissue arrangement and timing do not measure transport efficiency. DESTINY-Breast03 compares trastuzumab deruxtecan with T-DM1; the response figure is not evidence that the animated mechanism predicts an individual outcome.

How this example could support a program

A content foundation for a physician education program about antibody–drug conjugates, with learning objectives built around delivery, uptake and intracellular action. The film introduces the sequence, the interactive experience supports questions about individual steps, and the figures can carry the explanation into a medical presentation.