Study of the CHK1 Inhibitor BBI-355, an ecDNA-directed Therapy, in Subjects With Tumors With Oncogene Amplifications

• Status: Recruiting
• Trial end date: 2026-01-31
• Target enrollment: 0
• Participant gender: All

Summary

BBI-355 is an orally available, potent, and selective checkpoint kinase 1 (or CHK1) small molecule inhibitor in development as an ecDNA (extrachromosomal DNA) directed therapy (ecDTx). This is a first-in-human, open-label, non-randomized, 3-part, Phase 1/2 study to determine the safety profile and identify the maximum tolerated dose and recommended Phase 2 dose of BBI-355 administered as a single agent or in combination with select therapies.

• Phase: Phase 1
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: Boundless Bio

Criteria

Key Inclusion Criteria:

• Locally advanced or metastatic non-resectable solid tumors, whose disease has progressed despite all standard therapies or for whom no further standard or clinically acceptable therapy exists,

• Evidence of oncogene amplification,

• Availability of FFPE tumor tissue, archival or newly obtained,

• Measurable disease as defined by RECIST Version 1.1,

• Adequate hematologic function,

• Adequate hepatic and renal function,

• Eastern Cooperative Oncology Group performance status (ECOG PS) 0 or 1,

• Other inclusion criteria per study protocol.

Key Exclusion Criteria:

• Prior exposure to CHK1 inhibitors,

• Hematologic malignancies,

• Primary CNS malignancy, leptomeningeal disease, or symptomatic active CNS metastases, with exceptions per study protocol,

• Prior or concurrent malignancies, with exceptions per study protocol,

• History of HBV, HCV or HIV infection,

• Clinically significant cardiac condition,

• Active or history of interstitial lung disease (ILD) or pneumonitis, or history of ILD or pneumonitis requiring steroids or other immunosuppressive medications,

• QTcF > 470 msec,

• Prior organ allograft transplantations or allogeneic peripheral blood stem cell/bone marrow transplantation,

• Other exclusion criteria per study protocol.