Zanidatamab
Zanidatamab is a bispecific HER2-directed antibody used to treat HER2-positive cancers. It binds to two different sites on the HER2 receptor, causing receptor internalization and reduction on tumor cell surfaces, while also engaging the immune system to attack cancer cells. This targeted therapy is primarily used in patients with advanced or metastatic HER2-positive biliary tract cancer and gastric cancer.
A targeted bispecific antibody that attacks HER2-positive cancer cells by binding to two sites on the HER2 receptor and triggering immune responses.
This medication carries a boxed (black box) warning — the strongest type of FDA warning. Review the full prescribing information before use.
Key facts at a glance
- ATC
- L01FD07
- RxNorm
- 2698198
- Generic
- Zanidatamab
- Class
- atc-l01
- Brands
- Ziihera
- Availability
- rx
- Lactation
- unknown
- Routes
- —
- Forms
- injection
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Treatment of adult patients with previously treated, unresectable, locally advanced or metastatic HER2-positive biliary tract cancer. Also being studied for other HER2-positive solid tumors including gastric and colorectal cancers.
Zanidatamab is a bispecific antibody that simultaneously binds to two distinct extracellular domains of the HER2 receptor. This dual binding leads to HER2 receptor internalization and downregulation on tumor cells, inhibiting tumor cell growth. The antibody also engages immune effector functions including complement-dependent cytotoxicity to destroy cancer cells.
Administered via intravenous infusion. Common side effects include diarrhea, infusion-related reactions, and fatigue. Cardiac monitoring may be required during treatment. Must be prescribed by a qualified oncologist experienced in cancer therapy.
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed July 26, 2026. · Read our editorial policy