05:51 PM EST, 12/12/2024 (MT Newswires) -- Boundless Bio ( BOLD ) said late Thursday it made a "strategic decision" not to continue dose escalation of Part 1 or proceed into the Part 2 portion of a clinical trial for the oral inhibitor BBI-825 in patients with solid tumors.

The decision follows an assessment of preliminary pharmacokinetic data showing a lack of dose-proportional exposure, as well as the increasing complexity and associated development costs related to the evolving landscape of mutated cancer treatments.

Meanwhile, enrollment is ongoing in Boundless's phase 1/2 clinical trial of BBI-355 as a single agent and in combination with targeted therapies for patients with oncogene-amplified solid tumors.

The company reaffirmed its expectation to report preliminary clinical proof-of-concept safety and antitumor activity data in H2 2025.

"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," Chief Executive Zachary Hornby said.

The decision also "extends our operating runway into 2027, well beyond the anticipated milestones for both BBI-355 and ecDTx 3," Hornby added.