BBI-098

BBI-098 is an investigational, oral, selective checkpoint kinase 1 (CHK1) inhibitor developed by Boundless Bio. It is designed to penetrate the central nervous system (CNS), as demonstrated in preclinical models. The drug targets CHK1, a key regulator of the cellular response to replication stress—a vulnerability in oncogene-amplified cancer cells that rely on extrachromosomal DNA (ecDNA). By inhibiting CHK1, BBI-098 aims to disrupt DNA damage repair and induce cell death preferentially in cancer cells with high replication stress. The compound is being considered for development as a treatment for CNS cancers such as glioblastoma and brain metastases. As of early 2025, its highest development phase is preclinical[1][2][4].