The U.S. Food and Drug Administration (FDA) has granted accelerated approval to Zymeworks' Ziihera (zanidatamab) for the treatment of HER2-positive biliary tract cancer (BTC). This approval signifies a crucial advancement in the therapeutic landscape for patients with this aggressive cancer, marking Ziihera as the first dual HER2-targeted bispecific antibody approved in the U.S. for this indication.
The accelerated approval is specifically for patients with HER2-expressing, unresectable, locally advanced, or metastatic BTC who have experienced disease progression following prior systemic therapy. This decision addresses a significant unmet need in a patient population with limited treatment options.
The FDA's decision was based on data demonstrating a clinically meaningful objective response rate (ORR) in patients treated with Ziihera. While specific data details were not provided in the source, the approval pathway necessitates further confirmatory trials to verify the clinical benefit. Continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial(s).
Biliary tract cancers are a group of rare and aggressive cancers that occur in the bile ducts and gallbladder. HER2 overexpression is observed in a subset of these cancers, making it a relevant therapeutic target. The dual-targeting mechanism of zanidatamab offers a novel approach to HER2 inhibition, potentially overcoming resistance mechanisms associated with traditional HER2-targeted therapies.
Zymeworks is currently working to fulfill the post-marketing requirements to confirm the clinical benefit of zanidatamab in HER2-positive BTC. Further details regarding dosing regimens, administration routes, patient population, and inclusion criteria were not available in the provided source.
