Zymeworks Inc. (NYSE: ZYME) Reports Encouraging Data Showing Zanidatamab’s Durability and Response Rate in HER2-Poastiver GEA

Zymeworks Inc. (NYSE: ZYME) has announced that its HER2-targeted bispecific antibody, Zanidatamab, showed encouraging durability and response rates in first-liner HER2-positive Gastroesophageal Adenocarcinoma (GEA).

Zymeworks presents encouraging zanidatamab data at ESMO congress 

Memorial Sloan Kettering Cancer Center Medical Oncologist Geoffrey Ku, who is the study’s led investigator, presented the data at the ESMO Annual Congress.  Data presented was from the clinical trial of 36 patients who received zanidatamab to treat HER2 expressing GEA in combination with mFOLFOX6 or CAPOX. 

Interestingly 28 patients who had metastatic HER2-positive GEA showed cORR of 75% following treatment with zanidatamab, including chemotherapy. Also, a disease control rate of 89% was observed overall and a cORR of 93% with DCR of 100% in the expected third phase dose of zanidatamab plus CAPOX/FP. In addition, there was reduced tumor size in all patients apart from one. 

Ku said, “Despite recent advances, metastatic HER2-expressing GEA has high morbidity and mortality, and new treatment options are desperately needed. The data presented today at ESMO demonstrate the potential of zanidatamab in the first-line setting, highlighted by response rates and durability that compare favorably to the current standard of care as well as to emerging treatments. These data support further evaluation of zanidatamab plus chemotherapy in a randomized pivotal trial in first-line HER2-positive GEA.”

Zanidatamab offers more benefit due to bi-specific approach 

Around 20% of GEA patients show overexpression of HER2. Currently, the only available HER2-targeted therapy in 1L treatment for HER2-positive GEA patients is Herceptin (trastuzumab). Zanidatamab results in various action mechanisms due to its bi-specific approach that offers more therapeutic benefits exceeding two monoclonal antibodies combination. 

Interim CEO Neil Josephson said, “Herceptin and chemotherapy have been the standard of care in first-line HER2-positive GEA for over 10 years. The data presented today give us the confidence that we have developed a next-generation HER2-targeted agent that has the potential to provide patients with an improved option in this setting.”