Boundless Bio, Inc. is a clinical-stage oncology company, which is dedicated to unlocking a new paradigm in cancer therapeutics that addresses the significant unmet need in patients with oncogene amplified tumors by targeting extrachromosomal DNA. The company is headquartered in San Diego, California and currently employs 64 full-time employees. The company went IPO on 2024-03-28. Using its proprietary Spyglass platform, it identifies targets essential for ecDNA functionality in oncogene amplified cancer cells, then designs and develops small molecule drugs called ecDNA-directed therapeutic candidates (ecDTx) to inhibit those targets. The Company’s lead therapeutic candidate ecDTx, BBI-355, is an oral, selective inhibitor of checkpoint kinase 1 (CHK1), which manages ecDNA replication and transcription in cancer cells. BBI-355 demonstrated CHK1 inhibition and tumor regressions in oncogene amplified preclinical cancer models, including those enabled by ecDNA, and is being studied in a first-in-human, Phase I/II clinical trial in patients with oncogene amplified cancers. Its next program is directed at a previously undrugged kinesin target.