Business Description

1. Orga nization Descripti on of the Business BridgeBio Oncology Therapeutics, Inc. (“BBOT,” the “Company,” “we,” “our,” or “us”), formerly known as Helix Acquisition Corp. II (“Helix”), is a clinical-stage biopharmaceutical company advancing a next-generation pipeline of novel small molecule therapeutics targeting RAS and Phosphoinositide 3-kinase (“PI3K”) malignancies. BBOT is headquartered in South San Francisco, California. de-SPAC Transaction On February 28, 2025, TheRas Inc. (“Legacy BBOT”), a privately held Delaware corporation, entered into a definitive business combination agreement (“Business Combination Agreement”) with Helix, a publicly traded special purpose acquisition company (“SPAC”) listed on Nasdaq under the ticker symbol “HLXB.” On August 11, 2025 (the “Closing”), Helix II Merger Sub, Inc., a wholly-owned subsidiary of Helix, merged with and into Legacy BBOT, with Legacy BBOT surviving the merger as a wholly-owned subsidiary of Helix (“Merger”). In connection with the Merger, Helix changed its name to BridgeBio Oncology Therapeutics, Inc., and the combined company became listed on Nasdaq under the new ticker symbol “BBOT” (“de-SPAC Transaction”). Immediately prior to the closing of the de-SPAC Transaction, Helix issued and sold shares of its common stock to investors in a private placement financing for an aggregate purchase price of $ 260.9 million (“PIPE Financing”). The de-SPAC Transaction was accounted for as a reverse recapitalization with Legacy BBOT being the accounting acquirer, and Helix identified as the acquired company for accounting purposes (see Note 3). Accordingly, prior to the Closing, all historical financial information presented in the consolidated financial statements represents the balances and activity of Legacy BBOT. At the Closing, each outstanding share of Legacy BBOT common stock was exchanged for shares of BBOT common stock based on a ratio of approximately 0.0889 (“Consideration Ratio”). For periods prior to the Closing, the reported share and per share information has been retroactively adjusted to reflect the Consideration Ratio. Material Related Party Transactions BridgeBio Pharma, Inc. is a commercial-stage biopharmaceutical company founded to discover, create, test, and deliver transformative medicines to treat patients who suffer from genetic diseases. BridgeBio Pharma, Inc. and its controlled entities (collectively, “BridgeBio Pharma”) were related parties of Legacy BBOT prior to the Closing and remained related parties of the Company after the Closing. As discussed in Note 13, the Company had material related party transactions with BridgeBio Pharma during the periods presented in these consolidated financial statements. Basis of Presentation and Principles of Consolidation These consolidated financial statements are prepared in accordance with generally accepted accounting principles in the United States (“US GAAP”). All costs, as well as assets and liabilities directly associated with the Company’s business activity, are included in the consolidated financial statements. In connection with the de-SPAC Transaction, as the successor entity following the Closing, BBOT became the reporting entity and consolidates the balances and activity of Legacy BBOT. The financial information presented in these consolidated financial statements reflects the balances and results of operations of the combined entity post-Merger. Prior to the Closing, all references to BBOT or the Company are related to the balances and activity of Legacy BBOT. All intercompany balances have been eliminated in consolidation. From its inception through the issuance of the Series B on April 30, 2024, Legacy BBOT had been majority-owned and controlled by BridgeBio Pharma. Prior to April 30, 2024, the Company operated as part of BridgeBio Pharma. From inception through April 30, 2024, these consolidated financial statements have been derived from BridgeBio Pharma’s historical accounting records and are presented on a carve-out basis. The consolidated statement of operations includes allocations of certain general and administrative expenses to the Company from BridgeBio Pharma. The allocations have been determined on a reasonable basis. The related transactions are discussed further in Note 13. Following the Series B issuance, no individual investor or related party group held a controlling financial interest in the Company, and BBOT has operated independently from BridgeBio Pharma.…