The U.S. Food and Drug Administration (FDA) has expanded the label for Roche's Pathway anti-HER2/neu (4B5) Rabbit Monoclonal Primary Antibody test, making it the first FDA-approved companion diagnostic to identify biliary tract cancer (BTC) patients who may benefit from HER2-targeted treatment with Jazz Pharmaceuticals' Ziihera (zanidatamab-hrii). This approval marks a significant advancement in personalized medicine for a cancer with limited treatment options and poor prognosis.
Significance of the Approval
Biliary tract cancer, comprising about 3% of gastrointestinal cancers in the United States, often presents at advanced stages, leading to a dismal five-year survival rate as low as 3% for metastatic disease. Until now, there was no standardized, FDA-approved test to identify BTC patients with HER2 overexpression who could benefit from targeted therapies. The Pathway anti-HER2/neu (4B5) test fills this critical gap, potentially improving clinical outcomes by enabling clinicians to select appropriate treatments based on a patient's HER2 status.
Jill German, Head of Pathology Lab at Roche Diagnostics, stated, "This test is a step forward in furthering access to personalized medicine... Now, these patients have access to the first standardized test that could make them eligible for targeted therapy, potentially improving clinical outcomes."
Technical Details and Methodology
The Pathway anti-HER2/neu (4B5) Rabbit Monoclonal Primary Antibody test is designed to deliver clear and reliable results, aiding therapeutic decisions. It is used in conjunction with Roche's fully automated Ventana BenchMark slide staining instrument, which standardizes all immunohistochemistry (IHC) processes, from baking to staining. This standardization minimizes human error and reduces variability inherent in manual or semi-automated IHC methods.
HER2 (Human Epidermal growth factor Receptor 2) is a receptor protein that is expressed in a variety of cancers. It serves as a predictive biomarker to help determine if a patient will respond to HER2-targeted therapy.
Disease Burden and Current Landscape
Approximately 8,000 people in the United States are diagnosed with bile duct cancer annually. According to the National Cancer Institute, there have been around 41,630 cases of bile duct cancer confirmed this year, representing 2.1% of all cancer cases, resulting in 29,840 deaths, representing 4.9% of all cancer-related deaths this year. The rate of new cases was 9.4 per 100,000 men and women per year. The average age of diagnosis is in the 70s, although younger individuals can also be affected.
Nearly all bile duct cancers are cholangiocarcinomas, a type of adenocarcinoma. The approval of Roche's companion diagnostic offers a new avenue for identifying patients who may benefit from HER2-targeted therapies like Ziihera, representing a significant step forward in improving outcomes for this challenging cancer.
