Exhibit 99.1 Arcus Biosciences Reports First-Quarter 2024 Financial Results and Provides a Pipeline Update • Arcus data will be disclosed in two oral presentations at the 2024 American Society of Clinical Oncology (ASCO) Annual Meeting ◦ Updated data, including median progression-free survival (PFS), from EDGE-Gastric evaluating domvanalimab plus zimberelimab and chemotherapy in upper GI cancers ◦ Data, including overall survival (OS) and PFS, from ARC-9 evaluating an etrumadenant plus zimberelimab-based tr ...