On November 20, local time, Jazz Pharmaceuticals announced that the U.S. FDA has accelerated the approval of its HER2-targeted bispecific antibody Zanidatamab (Ziihera), developed in collaboration with Zymeworks, for marketing for the treatment of patients with previously treated, unresectable, locally advanced or metastatic HER2-positive biliary tract cancer.

The press release pointed out that this is the first and only HER2 bispecific antibody approved by the FDA for HER2+ biliary tract cancer.

Zanidatamab (ZW25) is a bispecific antibody based on the Zymeworks Azymetric platform that can simultaneously bind to two non-overlapping HER2 epitopes, i.e., biparatopic binding. This unique design can form multiple mechanisms of action, including dual blocking of HER2 signals, enhanced binding and removal of HER2 proteins on the cell surface, and strong antibody effector functions to enhance anti-tumor activity in patients.

Previously, Zenidatumomab has been granted breakthrough therapy designation, fast track qualification, priority review qualification, orphan drug qualification, etc. by the FDA, and has been granted breakthrough therapy and priority review by NMPA.

Zenidatumomab was originally developed by Zymeworks. As early as 2018, BeiGene acquired exclusive rights to it and another bispecific ADC in Asia (excluding Japan), Australia and New Zealand through a $430 million collaboration.

In October 22, Jazz reached a $1.76 billion collaboration with Zymewarks, obtaining its rights in the United States, Europe, Canada, Japan and other regions.

At present, China NMPA has accepted the marketing application of Zenidatuzumab for the second-line treatment of HER2+ biliary tract cancer (CXSS2400056) and included it in the priority review, and it is expected to be approved in the second quarter of next year.

Zenidatuzumab's approval in the United States is based on the data of the Phase IIb clinical trial HERIZON-BTC-01. In the first cohort of HERIZON-BTC-01, 62 patients with HER2-positive biliary tract cancer were evaluated for the efficacy of Zenidatuzumab. The main efficacy outcome indicators were ORR and DOR determined by ICR according to RECISTv1.1.1. The study showed that the ORR was 52% and the median DOR was 14.9 months.

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