BridgeBio Oncology Therapeutics (BBOT) Study Update summary

Portfolio and Strategy Highlights

• Advancing a differentiated portfolio of next-generation small molecule therapies targeting the RAS and PI3Kα pathways for oncology, focusing on optimized target coverage and combination strategies for KRAS-driven cancers.

• Portfolio includes BBO-8520 (KRAS G12C on-off inhibitor), BBO-11818 (pan-KRAS inhibitor), and BBO-10203 (RAS/PI3K alpha breaker), with multiple clinical-stage assets and value inflection points expected in 2026.

• Designed for dual inhibition of KRAS ON/OFF states and panRAS inhibition of PI3Kα activation, targeting over 250,000 annual incident patients in the U.S.

• Strong financial position supports operations into 2028.

BBO-8520 (KRAS G12C ON/OFF Inhibitor) Clinical Results

• Achieved a 65% objective response rate and 100% disease control rate in previously treated KRASG12C NSCLC patients, with 83% of patients eligible for 6-month follow-up remaining on treatment for at least 6 months.

• Demonstrated a favorable and differentiated safety profile, with no dose-limiting toxicities or grade ≥4 treatment-related adverse events; most common side effects were mild gastrointestinal symptoms and no grade 3 or higher liver toxicity.

• Combination with pembrolizumab showed early efficacy signals and a distinct, tolerable safety profile without increased liver enzyme elevations, with all evaluable patients experiencing tumor reduction.

• Encouraging efficacy in STK11/KEAP1 co-mutant tumors, a highly resistant population, with all five initial patients achieving partial response.

• Additional data updates and combination studies with BBO-10203 are planned for the second half of 2026.

BBO-11818 (pan-KRAS ON/OFF Inhibitor) Clinical Results

• Orally bioavailable, reversible pan-KRAS inhibitor with strong monotherapy activity and promising combination potential, showing anti-tumor activity and favorable safety profile.

• Early efficacy includes a confirmed partial response in pancreatic ductal adenocarcinoma with a 56% tumor reduction, the first publicly disclosed monotherapy pan-KRAS response in PDAC.

• Monotherapy treatment in 13 patients was generally tolerable, with no dose-limiting toxicities; GI-related adverse events were most common.

• Dose escalation ongoing, with 600 mg BID covering G12D and G12V mutant alleles; expansion and combination cohorts planned.

• Additional monotherapy and combination data updates are expected in the second half of 2026.