Policy & Regulation
Zymeworks Receives FDA Breakthrough Therapy Designation for HER2-Targeted Bispecific Antibody Zanidatamab in Patients with Biliary Tract Cancer
30 November 2020 - - The US Food and Drug Administration has granted Breakthrough Therapy designation for zanidatamab in patients with previously-treated HER2 gene-amplified biliary tract cancer, Canada-based biopharmaceutical company Zymeworks Inc. (NYSE: ZYME) said.

The FDA grants Breakthrough Therapy designation to new medicines that are intended to treat a serious condition and where clinical evidence indicates that the drug may demonstrate substantial improvement over available therapy on a clinically significant endpoint.

Zanidatamab will now be eligible for Accelerated Approval, Priority Review and Rolling Review, as well as intensive FDA guidance on an efficient drug development program.

Earlier this year, Zymeworks initiated a global Phase 2b registration-enabling study of single agent zanidatamab in patients with previously treated HER2 gene-amplified BTC.

This study, which is currently enrolling patients, is designed to support accelerated approval based on a primary endpoint of objective response rate, and secondary endpoints of duration of response and safety and may enable submission of a Biologics License Application as early as 2022.

This Breakthrough Therapy designation was based on an ongoing clinical trial of zanidatamab in patients with locally advanced (unresectable) and/or metastatic HER2-expressing tumors including BTC.

Updated clinical data for single agent zanidatamab patients with BTC has been accepted for presentation at the upcoming American Society of Clinical Oncology's Virtual Gastrointestinal Cancers Symposium (ASCO GI) January 15-17, 2021.

Zanidatamab is a bispecific antibody, based on Zymeworks' Azymetric platform, that can simultaneously bind two non-overlapping epitopes of HER2, known as biparatopic binding.

This unique design results in multiple mechanisms of action including dual HER2 signal blockade, increased binding, and removal of HER2 protein from the cell surface, and potent effector function leading to encouraging antitumor activity in patients.

Zymeworks is developing zanidatamab in multiple Phase 1, Phase 2, and registration-enabling clinical trials globally as a targeted treatment option for patients with solid tumors that express HER2.

In addition to Breakthrough Therapy designation for zanidatamab in BTC, the US FDA has granted two Fast Track designations to zanidatamab, one as a single agent for refractory BTC and one in combination with standard of care chemotherapy, for first-line gastroesophageal adenocarcinoma.

Zanidatamab has also received Orphan Drug designations for the treatment of biliary tract, gastric and ovarian cancers from the US FDA, as well as Orphan Drug designation for the treatment of gastric cancer from the European Medicines Agency.