Boundless Bio (BOLD) Corporate presentation summary

Unmet medical need and scientific foundation

• Oncogene amplified cancers represent a significant unmet need, with poor survival and limited response to current targeted or immunotherapies.

• Approximately 1.3 million new patients per year in major markets are affected by oncogene amplified cancers.

• ecDNA, cancer-specific circular DNA, is a root cause of oncogene amplification and is not found in normal tissue or blood.

• Around 25% of cancer patients have amplified oncogenes, and about half of high-copy amplifications occur on ecDNA.

• Amplifications on ecDNA are associated with worse survival and drive resistance to multiple therapies.

Mechanism and impact of ecDNA in cancer

• ecDNA enables rapid adaptation and oncogene switching, fueling resistance to targeted therapies and combination regimens.

• Tumors with ecDNA can dynamically change oncogene copy number in response to therapeutic pressure, making traditional targeted approaches less effective.

• ecDNA is present in 14-17% of cancer specimens at diagnosis across multiple tumor types.

• Most common high copy number oncogene amplifications frequently occur on ecDNA, correlating with poor prognosis.

• Targeting only the amplified oncogenes is insufficient due to ecDNA-driven plasticity.

Platform and pipeline overview

• The Spyglass platform leverages ecDNA biology to identify synthetic lethal targets in oncogene amplified cancers.

• Proprietary multi-omic screens and curated tumor models are used to discover novel drug targets essential for ecDNA function.

• The pipeline includes BBI-940 (Kinesin degrader, Phase 1), BBI-355 (CHK1 inhibitor), and BBI-825 (RNR inhibitor), each targeting distinct ecDNA lifecycle nodes.

• Additional discovery efforts focus on epigenetic regulators, ubiquitin enzymes, and ATPases.

• The company is well-funded, with a cash runway into the second half of 2028.