Boundless Bio, Inc.

Boundless Bio is a clinical-stage oncology company focused on developing cancer therapeutics targeting extrachromosomal DNA (ecDNA) amplification in tumors. The company's approach centers on identifying and inhibiting oncogenes that exist on ecDNA—DNA elements distinct from chromosomal DNA that can drive cancer progression. The lead product candidate, BBI-355, is an oral checkpoint kinase 1 inhibitor currently in Phase 1/2 clinical trials for patients with oncogene-amplified cancers. A second development candidate, BBI-098, is in preclinical evaluation and demonstrates enhanced checkpoint kinase 1 inhibition with central nervous system penetrance.

Beyond therapeutic candidates, Boundless Bio operates a companion diagnostics offering called ECHO, a test designed to detect ecDNA in patient tumor specimens to identify eligible patients for treatment. The company also maintains the Spyglass platform, an internal tool used to identify druggable targets in oncogene-amplified cancers. These diagnostic and discovery capabilities support the company's pipeline expansion strategy.

The company operates with approximately 64 full-time employees and is headquartered in San Diego, California. Boundless Bio was incorporated in Delaware in 2018, initially operating under the name Pretzel Therapeutics before rebranding in July 2019. The company is publicly listed on Nasdaq.