Boundless Bio Q3 2024 Financial Results and Business Highlights

Enrollment is progressing in the BBI-355 POTENTIATE and BBI-825 STARMAP clinical trials, with initial proof-of-concept data expected in the second half of 2025. Cash position of $167 million, with operating runway into the fourth quarter of 2026.

SAN DIEGO, Nov. 07, 2024 – Boundless Bio (Nasdaq: BOLD), a clinical-stage oncology company exploring extrachromosomal DNA (ecDNA) biology to develop transformative therapies for patients with previously untreatable oncogene-amplified cancers, has recently shared its business updates and third-quarter financial results for 2024.

"The third quarter saw consistent progress across our portfolio, with the POTENTIATE and STARMAP trials actively enrolling patients," stated Zachary Hornby, President and CEO of Boundless Bio. "In September, we, along with our development partner SOPHiA GENETICS, presented analytical validation for our exclusive ecDNA diagnostic, ECHO. This is a significant step in identifying ecDNA positive patients for our clinical programs. We are financially equipped to advance our leading programs through proof-of-concept data, focusing on achieving meaningful outcomes for our patients and stakeholders."

Program Highlights and Upcoming Milestones

BBI-355, an innovative and potent CHK1 inhibitor aimed at cancer patients with driver oncogene amplifications, is proceeding well in the Phase 1/2 POTENTIATE clinical trial. This trial evaluates BBI-355 both as a single agent and in combination with targeted therapies for patients with oncogene-amplified solid tumors. No new safety issues have emerged, and the company expects to report initial proof-of-concept data in the latter half of 2025.

BBI-825, a novel and potent RNR inhibitor targeting ecDNA assembly and repair for cancer patients with resistance oncogene amplifications, is also progressing in the dose-escalation phase of the STARMAP clinical trial. Initial clinical proof-of-concept data is anticipated in the second half of 2025.

The company's third ecDTx program, directed at a previously unaddressed kinesin target crucial for ecDNA segregation, is advancing through lead optimization. In September, analytical validation data for the proprietary ecDNA diagnostic ECHO was presented at the European Society for Medical Oncology (ESMO) Congress. ECHO is now utilized as a clinical trial assay to ascertain the ecDNA status of patients enrolled in the BBI-355 POTENTIATE trial.

Third Quarter 2024 Financial Results

Cash Position: As of September 30, 2024, cash, cash equivalents, and short-term investments totaled $167.1 million.
R&D Expenses: Research and development expenses were $14.1 million for the third quarter of 2024, up from $11.6 million during the same period in 2023.
G&A Expenses: General and administrative expenses rose to $4.6 million for the third quarter of 2024, compared to $3.3 million for the same period in 2023.
Net Loss: The net loss for the third quarter of 2024 was $16.5 million, compared to $13.2 million for the same period in 2023.

About BBI-355

Boundless Bio’s leading ecDNA-directed therapy, BBI-355, is an oral, selective small molecule inhibitor of checkpoint kinase 1 (CHK1) currently in a Phase 1/2 POTENTIATE clinical trial for cancer patients with oncogene amplifications. CHK1 is essential in managing cells’ response to replication stress, particularly elevated in cancer cells with oncogene amplification, representing a key vulnerability. BBI-355 is designed to exploit this by disrupting CHK1 function, leading to catastrophic replication stress, thereby preferentially targeting cancer cells over healthy cells.

About BBI-825

BBI-825, Boundless Bio’s second ecDTx, is an oral, selective small molecule inhibitor of ribonucleotide reductase (RNR) being studied in the Phase 1/2 STARMAP clinical trial for colorectal cancer patients with BRAFV600E or KRASG12C mutations and resistance gene amplifications. Preclinical studies demonstrated that BBI-825 effectively inhibited RNR, leading to tumor growth inhibition and depletion of ecDNA, showing synthetic lethality in multiple oncogene-amplified preclinical cancer models.

About Boundless Bio

Boundless Bio is a clinical-stage oncology company focused on developing a new paradigm in cancer therapeutics by targeting ecDNA, responsible for oncogene amplification in over 14% of cancer patients. Their first ecDNA-directed therapy, BBI-355, is an oral inhibitor of CHK1 in a Phase 1/2 trial for oncogene-amplified cancer patients. Their second ecDTx, BBI-825, targets RNR and is in a Phase 1/2 trial for colorectal cancer patients with specific mutations and resistance gene amplifications. Boundless Bio, headquartered in San Diego, CA, leverages its Spyglass platform for additional programs in preclinical development and discovery.