{"entity":{"id":"bbi-355","kind":"drug","name":"BBI-355","aka":[],"tldr":"BBI-355 is an oral small-molecule inhibitor from Boundless Bio that reached phase 1 for solid tumours with oncogene amplifications; development has stopped.","summary":"BBI-355 is an oral small-molecule inhibitor from Boundless Bio. An oral selective inhibitor of checkpoint kinase 1, designed to target replication stress in oncogene-amplified cancers. Its furthest stage is phase 1, for solid tumours with oncogene amplifications. ClinicalTrials.gov registers it in one study linked below. Monotherapy and third-party combination arms of POTENTIATE stopped May 2025; enrolment of the BBI-355 + BBI-825 combination ceased January 2026; wind-down ongoing (10-Q). Registry NCT05827614 TERMINATED. Whether it works in people has not been established unless a trial below reports it.","status":"phase-1","asOf":"2026-11-03","links":[{"label":"Boundless Bio: sec.gov","url":"https://www.sec.gov/Archives/edgar/data/0001782303/000119312526339093/bold-20260630.htm"},{"label":"Boundless Bio: sec.gov","url":"https://www.sec.gov/Archives/edgar/data/0001782303/000119312526339093/bold-20260630.htm"},{"label":"Boundless Bio: clinicaltrials.gov","url":"https://clinicaltrials.gov/study/NCT05827614"},{"label":"ClinicalTrials.gov: trials of BBI-355","url":"https://clinicaltrials.gov/search?intr=BBI-355"}],"tags":["pipeline","ctgov-ingest","discontinued"],"related":[],"cancers":["metastatic-cancer"],"sections":[],"technologies":[],"targets":["chek1"],"drugs":[],"companies":["boundless-bio"],"institutions":[],"pathways":[],"terms":[],"trials":["nct05827614"],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"provenance":{"editedBy":"OnCo gap audit, class 5 (company pipeline pages and ClinicalTrials.gov v2)","editedOn":"2026-11-03"},"code":"BBI-355","modality":"Oral small-molecule inhibitor","mechanism":"An oral selective inhibitor of checkpoint kinase 1, designed to target replication stress in oncogene-amplified cancers.","approvals":[],"mechanismSteps":[],"toxicity":[],"access":[],"regulatoryEvents":[]},"route":"/drugs/bbi-355/","neighbours":{"cancer":[{"id":"metastatic-cancer","kind":"cancer","name":"Metastatic cancer (cancer that has spread)","route":"/cancers/metastatic-cancer/"}],"target":[{"id":"chek1","kind":"target","name":"CHEK1","route":"/targets/chek1/"}],"company":[{"id":"boundless-bio","kind":"company","name":"Boundless Bio","route":"/companies/boundless-bio/"}],"trial":[{"id":"nct05827614","kind":"trial","name":"Study of the CHK1 Inhibitor BBI-355, an ecDNA-directed Therapy (ecDTx), and the RNR Inhibitor BBI-825, in Subjects With Tumors With Oncogene Amplifications","route":"/trials/nct05827614/"}]}}