Roche has received FDA approval for a label expansion of its PATHWAY anti-HER2/neu (4B5) Rabbit Monoclonal Primary Antibody test, making it the first companion diagnostic to identify biliary tract cancer (BTC) patients eligible for HER2-targeted therapy with Jazz Pharmaceuticals' ZIIHERA (zanidatamab-hrii). This approval marks a significant advancement in personalized medicine for BTC, a cancer with limited treatment options and poor prognosis.
Addressing Unmet Needs in Biliary Tract Cancer
Biliary tract cancer accounts for 3% of all gastrointestinal cancers in the US, with a five-year overall survival rate of only 19% for localized disease and 3% for cancer that has spread. The lack of early detection tools and effective treatments contributes to these dismal statistics. Until now, no approved and validated HER2 test existed to identify eligible BTC patients. The PATHWAY HER2 (4B5) test aims to fill this critical gap by standardizing HER2 assessment and improving access to targeted therapies.
The Role of PATHWAY HER2 (4B5) in Identifying HER2-Positive Patients
HER2, a receptor protein expressed in various cancers, serves as a predictive biomarker for response to HER2-targeted therapy. The PATHWAY HER2 (4B5) test is designed to accurately and reliably determine HER2 status in BTC tissue samples. According to Jill German, Head of Pathology Lab at Roche Diagnostics, this test represents "a step forward in furthering access to personalised medicine" and could potentially improve clinical outcomes for BTC patients by making them eligible for targeted therapy.
How the Test Works
The PATHWAY HER2 (4B5) assay standardizes all immunohistochemistry (IHC) processes, minimizing human error and variability. The Roche HER2 (4B5) clone achieves consistently high proficiency assessment scores and demonstrates high concordance with HER2 FISH, empowering laboratories to employ a reliable HER2 IHC primary antibody.
Implications for Treatment with ZIIHERA
ZIIHERA is the first FDA-approved treatment for adults with previously treated, unresectable, or metastatic HER2-positive (IHC 3+) biliary tract cancer. The companion diagnostic approval of the PATHWAY HER2 (4B5) test ensures that patients who are most likely to benefit from ZIIHERA can be accurately identified, optimizing treatment outcomes. This combined approach represents a significant step forward in improving the care of patients with this aggressive cancer.
