Arcus Biosciences Inc., in a presentation on the opening day of the American Society of Clinical Oncology Gastrointestinal Cancers Symposium (ASCO GI), reported a 41% objective response rate across the first four cohorts in its phase I dose-escalation study of AB-680, a small-molecule CD73 inhibitor for treating metastatic pancreatic cancer. The data also showed 88% of patients experienced at least some shrinkage of their lesions.