Zymeworks reports Phase I data for ZW25 in HER2-expressing cancers

Zymeworks Inc. (NYSE:ZYME; TSX:ZYME) reported data from 17 evaluable patients with HER2-expressing breast or gastric cancer in the dose-escalation portion of an open-label, U.S. Phase I trial showing that ZW25 led to six partial responses, plus three cases of stable disease. ZW25 was well tolerated. Data were presented at the San Antonio Breast Cancer Symposium in December.

The trial is evaluating safety as its primary endpoint. Secondary endpoints include pharmacokinetics, objective response rate (ORR) and progression-free survival (PFS). The dose-escalation portion evaluated once-weekly 5, 10 and 15 mg/kg ZW25 and 20 mg/kg ZW25 every two weeks. The dose-expansion portion of the trial is evaluating 20 mg/kg ZW25 every two weeks in four expansion cohorts consisting of patients with HER2-high breast, HER2-high gastric, HER2-intermediate breast and other HER2-gene amplified cancers...