BBO-11818

SOUTH SAN FRANCISCO, CA, USA I April 01, 2025 I TheRas, Inc. d/b/a BridgeBio Oncology Therapeutics (“BBOT” or the “Company”), a clinical-stage biopharmaceutical company focused on RAS-pathway malignancies, today announced that the first patient has been dosed with BBO-11818 in the Phase 1 KONQUER-101 trial for advanced solid tumors. BBO-11818 is an orally bioavailable small molecule dual inhibitor that directly binds to both the “ON” and “OFF” states of KRAS. KONQUER-101 will enroll patients globally with certain KRAS mutations. “The dosing of the first patient is a major milestone in assessing BBO-11818’s potential benefit for patients with tumors driven by mutant KRAS,” said Dr. Ignacio Garrido-Laguna, MD, PhD, Principal Investigator at Huntsman Cancer Institute at the University of Utah. “We are committed to bringing cutting-edge therapies to patients with advanced cancer in the Mountain Region. BBO-11818 has the potential to safely achieve optimal target inhibition and combine with other targeted therapies. We look forward to evaluating it in the KONQUER-101 trial.” BBO-11818 was designed to non-covalently bind both the inactive GDP-bound “OFF” and active GTP-bound “ON” forms of KRAS G12D and KRAS G12V . In cellular assays, EC 50 values for pERK inhibition in selected KRAS G12D and G12V-mutant cell lines range from sub-nanomolar to single-digit nanomolar potency. BBO-11818 is similarly effective in reducing cell viability in KRAS G12D , KRAS G12V , and KRAS G12C -mutant cell lines. Further, NRAS and BRAF mutant cell lines show insensitivity to BBO-11818, and the molecule exhibits more than 500-fold selectivity for KRAS over H- and NRAS. “There is a great need for new therapies that can safely treat patients with tumors driven by KRAS mutations, as the current standard of care lacks satisfactory options as monotherapy or to enable combinations of KRAS targeted therapies with other targeted agents,” said Yong (Ben) Ben, MD, Chief Medical and Development Officer of BBOT. “BBO-11818 marks the third molecule entering the clinic for BBOT, further proving our capability to advance novel programs into the clinic. Of note, our portfolio is uniquely positioned to deliver the combination of MAPK (BBO-8520 and BBO-11818) and PI3Kα/AKT (BBO-10203) co-inhibition, with a therapeutic index. We hope this will bring unprecedented benefit to patients with RAS-driven cancers.” The discovery of BBO-11818 was the result of a collaboration between the RAS Initiative at Frederick National Laboratory, Lawrence Livermore National Laboratory, and BBOT. About BBOT BBOT is a clinical-stage biopharmaceutical company advancing a next-generation pipeline of novel small molecule therapeutics targeting RAS and PI3Kα malignancies. Initially formed as a subsidiary of BridgeBio Pharma, Inc. (Nasdaq: BBIO), BBOT has the goal of improving outcomes for patients with cancers driven by the two most prevalent oncogenes in human tumors. For more information, visit bridgebiooncology.com . SOURCE: BridgeBio Oncology Therapeutics

BBOT’s BBO-8520 is currently undergoing the Phase I ONKORAS-101 trial. Credit: CrizzyStudio/Shutterstock. BridgeBio Oncology has entered a definitive merger agreement with Helix Acquisition Corp II, which will result in the formation of a combined entity known as BridgeBio Oncology Therapeutics. The transaction includes $196m from Helix’s trust account and an additional $260m from a private investment in public equity (PIPE), led by Cormorant Asset Management. Assuming no redemptions, the total proceeds are anticipated to be $450m, combining funds held in the Helix trust account and PIPE financing. The PIPE, featuring several investors, funds the advancement of BBOT’s three drug development programmes: BBO-8520, BBO-10203 and BBO-11818. The merger is expected to provide BBOT with $550m in cash. BBOT CEO Eli Wallace stated: “This financing and transaction mark a significant milestone for our company. We are profoundly grateful to the patients who participate in our trials, our dedicated BBOT team members, and our investors. “We believe this transaction is the optimal path to advance our programmes and make a meaningful impact on patients affected by deadly cancers.” BBOT’s BBO-8520, a KRAS G12C inhibitor, is currently undergoing the Phase I ONKORAS-101 trial for treating KRAS G12C mutant non-small cell lung cancer. BBO-10203, tailored to inhibit RAS-PI3Kα interaction, is being evaluated in the Phase I BREAKER-101 trial. The first subject dosing with BBO-11818, a pan-KRAS inhibitor, is anticipated in the first half of 2025. At closing, BBOT as the combined company will have an implied pro forma equity value of $949m, with BBOT shareholders rolling their full equity into the new entity. The transaction, anticipated to be completed in the third quarter of 2025, has received approval from both companies’ boards and awaits stockholder consent and other customary closing conditions. Leerink Partners and Morgan Stanley, along with Cantor and Oppenheimer & Co, served as Helix’s placement agents, while Piper Sandler served as capital markets advisor to BBOT. Goodwin Procter, White & Case and Kirkland & Ellis provided legal counsel to the involved parties.