# Zanidatamab zovodotin

Source: https://onco.cc/drugs/zanidatamab-zovodotin/  
OnCo record `zanidatamab-zovodotin` (Treatment). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Zanidatamab zovodotin joined the two-armed HER2 antibody zanidatamab to a cell-killing payload. It was tested in early trials in HER2-expressing cancers; the plain antibody went on to approval, the conjugate did not progress beyond phase 1.

## Summary

Zanidatamab zovodotin (ZW49) was Zymeworks' antibody-drug conjugate built on zanidatamab, the biparatopic HER2 antibody now approved as Ziihera. Binding two HER2 epitopes was intended to make the receptor cluster and internalise faster, delivering more of the auristatin payload into HER2-expressing tumour cells, including those with lower HER2 expression.

It was given intravenously in a phase 1 dose-escalation study across HER2-expressing solid tumours, including breast and gastro-oesophageal cancers. The programme was not advanced into registrational trials; it is named on the HER2-positive breast cancer page as one of the next-generation and biparatopic HER2 conjugates that followed trastuzumab deruxtecan.

## Fields

- Kind: Treatment
- Status: phase-1
- Last checked: 2026-09-17
- Also known as: ZW49
- Tags: subtype-drugs-wave
- Code: ZW49
- Modality: Biparatopic HER2 antibody-drug conjugate
- Mechanism: The biparatopic antibody zanidatamab, which binds two different HER2 domains at once, carried an auristatin payload; the dual binding clusters HER2 and drives the conjugate into the cell where the payload is released.

## Connected records

- drugs: [Trastuzumab deruxtecan](https://onco.cc/drugs/trastuzumab-deruxtecan/), [Zanidatamab](https://onco.cc/drugs/zanidatamab/)
- cancers: [HER2-positive breast cancer](https://onco.cc/cancers/breast-her2-positive/)
- technologies: [Antibody-drug conjugate (ADC)](https://onco.cc/technologies/adc/)
- targets: [HER2](https://onco.cc/targets/her2/)
- companies: [Zymeworks](https://onco.cc/companies/zymeworks/)

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JSON: https://onco.cc/api/v1/entities/zanidatamab-zovodotin.json