Boundless Bio (Nasdaq: BOLD) has announced strategic updates to its pipeline, focusing on its BBI-355 program and a novel third ecDNA directed therapy (ecDTx) while discontinuing the development of BBI-825. The decision follows an assessment of preliminary data from the Phase 1/2 STARMAP trial and the increasing complexity of the treatment landscape for BRAF V600E and KRAS G12C mutated cancers.
Pipeline Prioritization
The company's lead program, BBI-355, an oral CHK1 inhibitor, remains on track with preliminary clinical proof-of-concept safety and antitumor activity data expected in the second half of 2025. BBI-355 is currently being evaluated in the Phase 1/2 POTENTIATE clinical trial, both as a single agent and in combination with targeted therapies, for patients with oncogene-amplified solid tumors. Enrollment is ongoing.
Boundless Bio is also advancing its third ecDTx program, which targets a previously undrugged kinesin essential for ecDNA segregation. The company anticipates nominating a development candidate by mid-2025 and submitting an Investigational New Drug (IND) application in the first half of 2026.
Discontinuation of BBI-825
BBI-825, an oral RNR inhibitor, was being evaluated in the Phase 1/2 STARMAP clinical trial for patients with solid tumors, including those with BRAF V600E or KRAS G12C mutated colorectal cancer that has developed resistance oncogene amplifications. While BBI-825 has been generally well-tolerated, preliminary pharmacokinetic data from Part 1 of the trial showed a lack of dose-proportional exposure. Considering these data, along with the increasing complexity and associated development costs related to the evolving BRAF V600E and KRAS G12C mutated cancer treatment landscape, Boundless Bio has decided not to proceed into Part 2 of the STARMAP trial.
Leadership Changes
Boundless Bio also announced that Klaus Wagner, M.D., Ph.D., Chief Medical Officer (CMO), and Neil Abdollahian, Chief Business Officer (CBO), will be departing the company. James L. Freddo, M.D., will serve as Interim CMO. The company does not intend to appoint a new CBO at this time.
Strategic Focus
"After a thorough assessment of BBI-825’s emerging clinical data and anticipated development costs, particularly amid the dynamic and increasingly competitive landscape of BRAFV600E and KRASG12C-mutated cancer treatment, we have decided not to advance the STARMAP trial," said Zachary Hornby, President and CEO of Boundless Bio. "With this strategic decision, we are prioritizing resource allocation to BBI-355, which remains on-track for initial clinical proof-of-concept data in 2025, and our novel ecDTx 3 program, where we’ve made substantial preclinical progress and expect to nominate a development candidate by mid-2025. It also extends our operating runway into 2027, well beyond the anticipated milestones for both BBI-355 and ecDTx 3."
