Zymeworks updates clinical data for ZW25 anti-tumor candidate
Zymeworks presented updated ZW25 clinical data from the ongoing multi-center Phase 1 study which showed single agent ZW25, a bispecific antibody, induced anti-tumor activity and was well tolerated in heavily pretreated patients with a variety of HER2-expressing cancers. Of the 17 patients, eight had gastroesophageal cancers, four had colorectal cancer and five had other HER2-expressing cancers including gall bladder, cholangiocarcinoma, cervical, fallopian tube and salivary gland. The overall disease control rate, which includes patients with partial responses and stable disease was 82%. There were seven partial responses, seven stable disease and three progressive disease. The median progression-free survival in all 24 patients was 6.21 months. In the eight gastroesophageal cancer patients, who had a median of four prior systemic treatments, the response rate was 50%. In the four colorectal and five other HER2-expressing cancer patients the response rate was 33%. In the study, ZW25 was well tolerated. All treatment-related adverse events were Grade 1 or 2 with the exception of one patient with Grade 3 fatigue, and no treatment-related serious adverse events were seen.