Zanidatamab shows durable and meaningful responses in HER2-positive bile duct cancer

Zanidatamab shows durable and meaningful responses in HER2-positive bile duct cancer

Zanidatamab, a bispecific HER2-targeting antibody, delivered clinically meaningful and durable responses in patients with HER2-positive bile duct cancer (BTC), according to final results from the HERIZON-BTC-01 clinical trial led by researchers at The University of Texas MD Anderson Cancer Center.

In this clinical trial, zanidatamab demonstrated an objective response rate of 41.3% and a median duration of response of 15.5 months, while patients whose tumors had the highest levels of HER2 overexpression experienced even greater benefit - a response rate of 51.6% and a median duration of response of 18.1 months.

The results of this study, led by Shubham Pant, MD, professor of gastrointestinal medical oncology and investigational cancer therapeutics, were published inJAMA Oncology. The first test results were reported for the first timeThe Lancet Oncologyin June 2023.

The observed objective response rate, prolonged response duration and consistent activity in IHC3+ tumors highlight HER2 as a valid therapeutic target in biliary tract cancer and support the emerging role of zanidatamab in the treatment paradigm.”

Shubham Pant, MD, professor of gastrointestinal medical oncology and investigational cancer therapeutics

What significance do the results of the HERIZON-BTC-01 study have?

Inoperable or metastatic bile duct cancer (BTC) is a rare, aggressive cancer and has very limited treatment options once standard therapies no longer work. These results represent the largest HER2-targeted clinical database in BTC and provide the longest follow-up reported to date.

In a cohort of 80 patients, those who responded to zanidatamab reported significant improvements in their symptoms, particularly pain levels. Many experienced a reduction or stabilization of pain compared to baseline, suggesting that the treatment not only controlled tumor growth but also helped relieve disease-related discomfort. Additionally, patients who participated in the study long enough to complete follow-up visits demonstrated greater overall symptom control.

What impact does this study have on patients with bile duct cancer?

Zanidatamab is a bispecific antibody that binds to two different sites on the HER2 receptor, allowing it to more effectively inhibit the growth of cancer cells and promote immune-mediated elimination of tumor cells compared to traditional HER2-targeted therapies.

These study results directly supported the Food and Drug Administration's (FDA) accelerated approval of zanitamab for adults with previously treated, unresectable or metastatic IHC3+ bile duct cancer. The durability and safety profile suggest that zanidatamab has strong therapeutic potential for this difficult-to-treat cancer.

This study was supported by BeOne Medicines, Jazz Pharmaceuticals and Zymeworks.

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