Exhibit 99.1 Boundless Bio Reports Third Quarter 2024 Financial Results and Business Highlights Enrollment progressing in BBI-355 POTENTIATE and BBI-825 STARMAP clinical trials, with initial proof-ofconcept data expected in the second half of 2025 Cash position of $167 million, with operating runway into the fourth quarter of 2026 SAN DIEGO, November 7, 2024 – Boundless Bio (Nasdaq: BOLD), a clinical-stage oncology company interrogating extrachromosomal DNA (ecDNA) biology to deliver transformative therapie ...