The U.S. Food and Drug Administration (FDA) has granted approval for a label expansion of Roche's PATHWAY anti-HER2/neu (4B5) Rabbit Monoclonal Primary Antibody test, now indicated for biliary tract cancer (BTC). This approval designates the test as the first FDA-approved companion diagnostic to identify BTC patients who may benefit from treatment with Jazz Pharmaceuticals' ZIIHERA (zanidatamab-hrii). This advancement offers a new avenue for personalized medicine in treating this challenging cancer.
Addressing Unmet Needs in Biliary Tract Cancer
Biliary tract cancers account for approximately 3% of all gastrointestinal cancers in the United States. These cancers are often diagnosed at an advanced stage, leading to poor prognoses. The five-year overall survival rate is only 19% when the disease is localized and a mere 3% when it has metastasized. Until now, there has been a lack of approved and validated HER2 tests to identify BTC patients suitable for HER2-targeted therapies.
Jill German, Head of Pathology Lab at Roche Diagnostics, stated, "This test is a step forward in furthering access to personalised medicine. The prognosis for patients diagnosed with BTC is poor, as very few treatment options exist. Now, these patients have access to the first standardised test that could make them eligible for targeted therapy, potentially improving clinical outcomes."
Clinical Significance of ZIIHERA
ZIIHERA has received FDA approval as the first therapy for adults with previously treated, unresectable, or metastatic HER2-positive (IHC 3+) BTC. The PATHWAY HER2 (4B5) test plays a crucial role in identifying patients who are most likely to respond to this targeted treatment.
About the PATHWAY HER2 (4B5) Test
The PATHWAY anti-HER2/neu (4B5) Rabbit Monoclonal Primary Antibody test is designed to deliver timely, clear, and reliable results, thereby supporting informed therapeutic decisions. It is already utilized to determine the eligibility of breast cancer patients for HER2-targeted treatments such as Herceptin, Kadcyla, and Enhertu. The test is compatible with the fully automated VENTANA BenchMark slide staining instrument, ensuring consistent and accurate results.
The new indication for BTC significantly broadens the clinical utility of the test, making it an integral part of Roche's comprehensive gastrointestinal cancer solutions portfolio. This portfolio aims to provide diagnostic certainty in cancer care by standardizing immunohistochemistry (IHC) processes and minimizing human error and variability inherent in manual and semi-automated IHC methods.
According to Roche, the HER2 (4B5) clone consistently achieves high proficiency assessment scores compared to other clones and demonstrates high concordance with HER2 FISH, empowering laboratories to employ a reliable HER2 IHC primary antibody.
