Helix Acquisition Corp II-A美股招股说明书(2025-07-22版)

PROSPECTUS FOR UP TO 28,000,000 SHARES OF COMMON STOCK OF HELIX ACQUISITION CORP.II(WHICH WILL BE RENAMED “BRIDGEBIO ONCOLOGY THERAPEUTICS, INC.” FOLLOWING DOMESTICATIONIN THE STATE OF DELAWARE AND IN CONNECTION WITH THE BUSINESS COMBINATION DESCRIBED HEREIN) Statement/Prospectus.This purpose of this Supplement is to update and supplement certain information contained in the Proxy Statement/Prospectus to (i)reflect recent developments that occurred after the date of the Proxy Statement/Prospectus, (ii) revise the tier of the Nasdaq StockMarket for which PubCo has applied to list its securities from the Nasdaq Global Market to the Nasdaq Capital Market, and (iii) revisecertain disclosures relating to the management of PubCo following the closing of the Business Combination. Except as otherwise setforth below, the information set forth in the Proxy Statement/Prospectus remains unchanged. For clarity, additions to existing The information set forth below serves as a supplement to the Proxy Statement/Prospectus. Except as described herein, the informationprovided in the Proxy Statement/Prospectus continues to apply. To the extent this Supplement differs from or updates information intheProxy Statement/Prospectus,shareholders should rely on the information contained in this Supplement.The ProxyStatement/Prospectus contains important additional information. This Supplement should be read in conjunction with the ProxyStatement/Prospectus. BUSINESSCOMBINATION(AS DEFINED IN THE PROXY STATEMENT/PROSPECTUS)OR THE OTHERTRANSACTIONS CONTEMPLATED THEREBY, OR PASSED UPON THE ADEQUACY OR ACCURACY OF THEDISCLOSURE IN THE PROXY STATEMENT/PROSPECTUS. ANY REPRESENTATION TO THE CONTRARY IS ACRIMINAL OFFENSE. Global Market in the Proxy Statement/Prospectus and any of the annexes to the Proxy Statement/Prospectus shall be amended andrestated to “Nasdaq Capital Market”. Chief Financial Officer. Mr. Mehra will enter into an employment agreement with PubCo to be effective as of the Closing. Post-Closing Grants Executive OfficersFollowing the Closing of the Business Combination, PubCo intends to approve certain stock option grants to certain service providersof BBOT, including its executive officers. Non-Employee Directors Following the Closing of the Business Combination, PubCo intends to approve certain stock option grants to certain of its non-employee directors. The following amends and supplements pages xxxi – xxxii of the Proxy Statement/Prospectus by adding the underlined bolded text (indicated textually in the same manner as the following example:underlined bolded text) as set forth below: The third bullet point in response to the question “What interests do the BBOT directors and officers have in the BusinessCombination?” on pages xxxi – xxxii shall be revised to read as: Upon the completion of the Business Combination, the following persons are expected to be appointed Executive Officers of PubCo:Dr. Wallace, Mr. Mehra, Dr. Beltran and Dr. Ben. For a description of these arrangements see “Executive and Director Compensation of BBOT.” The following amends and supplements pages 122 – 178 of the Proxy Statement/Prospectus by adding the underlined bolded text (indicated textually in the same manner as the following example:underlined bolded text) as set forth below:(a)the first full paragraph under the subsection entitled “Interests of BBOT’s Directors and Officers - Other Compensation” on Upon the completion of the Business Combination, the following persons are expected to be appointed Executive Officers of Post-Closing Grants Executive Officers Effective Date. Each stock option will have a per share exercise price equal to the closing price of a share of PubCoCommon Stock on the Option Effective Date, as reported on the Nasdaq Capital Market. Each stock option will be Effective Date, subject to the applicable grantee’s continued service relationship with PubCo through each applicablevesting date. Each stock option will be subject to the terms and conditions of the PubCo Incentive Plan, and the applicable stock option agreement thereunder. Non-Employee DirectorsIn connection with the Business Combination, the PubCo Board intends to approve stock option grants to certain non-employee directors of PubCo. The PubCo Board intends to grant Drs. McCormick and Tipirneni and Mr.Bauer astock option to purchase a number of shares of PubCo Common Stock equal to approximately 0.115%, 0.066% and0.156%, respectively, of the shares of PubCo Common Stock outstanding immediately after the Closing, contingent onthe Closing and effective on the Option Effective Date, subject to each applicable director’s continuous servicerelationship with PubCo through such Option Effective Date. Each stock option will have a per share exercise priceequal to the closing price of a share of PubCo Common Stock on the Option Effective Date, as reported on the NasdaqCapital Market. Each stock option will be granted under the PubCo Incentive