NEW YORK – Boundless Bio on Tuesday began a Phase I/II trial of BBI-355 in patients with locally advanced or metastatic solid tumors with oncogene amplifications.
BBI-355 is a CHK1 inhibitor directed against extrachromosomal DNA (ecDNA), which is a driver of high copy number amplification in cancer. The study will include patients with liposarcoma, and lung, esophageal, gastric, breast, bladder, ovarian, endometrial, and head and neck cancers. Patients in the study must have progressed on standard therapies or be out of standard or clinically acceptable treatment options.
"Preclinically, single agent BBI-355 demonstrates potent anti-cancer activity in ecDNA-enabled oncogene-amplified tumor models and robust, synergistic efficacy in combination with select cancer therapies," Klaus Wagner, chief medical officer at Boundless Bio, said in a statement. "There is a large unmet medical need for cancer patients with oncogene amplification, and we look forward to working with some of the top US cancer centers to bring new and promising treatment options to these patients."
The trial will include three parts: a monotherapy dose-escalation portion, a combination dose-escalation portion in patients with specific oncogene amplifications, and a dose-expansion phase of BBI-355 in combination with select therapies in cancer patients with specific oncogene amplifications on ecDNA. In the third part of the study, researchers will use an ecDNA diagnostic clinical trial assay, called ecDNA Harboring Oncogenes, or ECHO, which was developed in collaboration with Sophia Genetics, to determine the presence of oncogenes amplified on ecDNA in patients' tumor samples.
BBI-355 is the firm's first candidate to enter clinical trials. Boundless is also developing other ecDNA-directed therapies that are in preclinical studies with the help of the ECHO diagnostic.