Tuesday, September 19, 2023
Boundless Bio, a clinical-stage precision oncology company with a focus on exploring the biology of extrachromosomal DNA (ecDNA) for innovative cancer therapies, has made an announcement regarding a clinical trial collaboration and supply agreement with Taiho Oncology, Inc. This collaboration aims to investigate the potential of Taiho's pan-FGFR inhibitor, LYTGOBI® (futibatinib), when used in combination with BBI-355, a selective small molecule inhibitor of CHK1, in patients with locally advanced or metastatic solid tumors displaying oncogene amplifications. BBI-355 is being considered as the first ecDNA-directed therapy in development for oncogene-amplified cancers.
Zachary Hornby, the President and CEO of Boundless Bio, emphasized the importance of this collaboration in advancing their clinical strategy. He pointed out that while FGFR inhibitors used as monotherapy have shown limited clinical benefits in patients with FGFR amplifications, the combination of BBI-355 with Taiho's futibatinib could potentially provide substantial anti-tumor activity. This combination therapy will undergo evaluation in the ongoing Phase 1/2 POTENTIATE trial.
Under the terms of the agreement, Taiho will provide futibatinib clinical drug supply at no cost for Boundless Bio's POTENTIATE trial. This trial is a Phase 1/2 study focused on patients with locally advanced or metastatic solid tumors displaying oncogene amplifications, particularly those who have experienced disease progression despite standard therapies or for whom no suitable treatment options are available.
The POTENTIATE trial comprises three parts: the dose escalation and expansion of BBI-355 as a single agent in cancer patients with oncogene amplifications, dose escalation of BBI-355 in combination with selected targeted therapies in cancer patients with specific oncogene amplifications, and dose expansion of BBI-355 in combination with selected targeted therapies in cancer patients with specific oncogene amplifications on ecDNA. BBI-355 is administered orally every other day, and the third part of the trial incorporates a proprietary bioinformatic diagnostic algorithm called ECHO (ecDNA Harboring Oncogenes) to detect oncogenes amplified on ecDNA in patient tumor samples.
BBI-355 is a novel, orally administered checkpoint kinase 1 (CHK1) inhibitor developed as a potential ecDNA-directed therapy for patients with oncogene-amplified cancers. CHK1 plays a critical role in cellular responses to DNA replication stress, which often arises due to oncogene amplification on ecDNA. By disrupting CHK1 function in oncogene-amplified cancer cells, BBI-355 aims to induce replication stress, selectively targeting cancer cells while sparing healthy cells. The identification of CHK1 as an essential ecDNA target was made through Boundless Bio's Spyglass research platform.