HLXB / Helix Acquisition Corp. II - Documents déposés auprès de la SEC, rapport annuel, procuration

Security Type

Calculation of Filing Fee Tables S-1 BridgeBio Oncology Therapeutics, Inc. Table 1: Newly Registered and Carry Forward Securities ☐Not Applicable Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered Proposed Maximum Offering Price Per Unit Maximum Aggregate Offering Price Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Car

As filed with the Securities and Exchange Commission on August 29, 2025 Registration No. 333-    UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 BRIDGEBIO ONCOLO

Table of Contents As filed with the Securities and Exchange Commission on August 29, 2025 Registration No.

BRIDGEBIO ONCOLOGY THERAPEUTICS, INC. 2025 STOCK OPTION AND INCENTIVE PLAN

EX-10.21 Exhibit 10.21 BRIDGEBIO ONCOLOGY THERAPEUTICS, INC. 2025 STOCK OPTION AND INCENTIVE PLAN SECTION 1. GENERAL PURPOSE OF THE PLAN; DEFINITIONS The name of the plan is the BridgeBio Oncology Therapeutics, Inc. 2025 Stock Option and Incentive Plan (the “Plan”). The purpose of the Plan is to encourage and enable the officers, employees, Non-Employee Directors and Consultants of BridgeBio Oncol

As filed with the Securities and Exchange Commission on August 14, 2025

As filed with the Securities and Exchange Commission on August 14, 2025 Registration No.

AMENDED AND RESTATED BRIDGEBIO ONCOLOGY THERAPEUTICS, INC. (the “Corporation”) Article I Stockholders

Exhibit 3.2 AMENDED AND RESTATED BYLAWS OF BRIDGEBIO ONCOLOGY THERAPEUTICS, INC. (the “Corporation”) Article I Stockholders Section 1. Annual Meeting. The annual meeting of stockholders (any such meeting being referred to in these Bylaws as an “Annual Meeting”) shall be held at the hour, date and place within or without the United States that is fixed by or in the manner determined by the Board of

CERTIFICATE OF INCORPORATION BRIDGEBIO ONCOLOGY THERAPEUTICS, INC. ARTICLE I

Exhibit 3.1 CERTIFICATE OF INCORPORATION OF BRIDGEBIO ONCOLOGY THERAPEUTICS, INC. ARTICLE I The name of the Corporation is BridgeBio Oncology Therapeutics, Inc. ARTICLE II The address of the Corporation’s registered office in the State of Delaware is 1209 Orange Street, in the City of Wilmington, County of New Castle, 19801. The name of its registered agent at such address is The Corporation Trust

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Exhibit 10.19 August 11, 2025 Uneek Mehra Re: Employment Agreement and Executive Severance Plan Participation Agreement Dear Uneek: Reference is made to the Business Combination Agreement, dated as of February 28, 2025 (as amended, restated or otherwise modified from time to time, the “BCA”), entered into by and among TheRas, Inc., a Delaware corporation (“BBOT”), Helix Acquisition Corp. II, a Cay

THERAS, INC. AMENDMENT NO. 1 TO THE 2016 EQUITY INCENTIVE PLAN

Exhibit 10.20 THERAS, INC. AMENDMENT NO. 1 TO THE 2016 EQUITY INCENTIVE PLAN TheRas, Inc. 2016 Equity Incentive Plan (the “Plan”) is hereby amended by the Board of Directors and stockholders of TheRas, Inc., a Delaware corporation, as follows: Item (a)(i) of Section 3 of the Plan is hereby amended by deleting it and replacing it with the following: “(i) Subject to Section 9(a) relating to Capitali

BBOT Debuts as Publicly Traded Company Focused on RAS-Pathway Malignances with a Potential to Realize the Full Promise of KRAS and PI3K Inhibition

Exhibit 99.4 BBOT Debuts as Publicly Traded Company Focused on RAS-Pathway Malignances with a Potential to Realize the Full Promise of KRAS and PI3K Inhibition ● Business combination transaction with Helix Acquisition Corp. II, a special purpose acquisition company sponsored by affiliates of Cormorant Asset Management, completed on August 11,2025 ● Closed concurrent $261 million private investment

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Exhibit 10.17 August 11, 2025 Dr. Pedro Beltran Re: Employment Agreement and Executive Severance Plan Participation Agreement Dear Pedro: Reference is made to the Business Combination Agreement, dated as of February 28, 2025 (as amended, restated or otherwise modified from time to time, the “BCA”), entered into by and among TheRas, Inc., a Delaware corporation (“BBOT”), Helix Acquisition Corp. II,

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 11, 2025 BRIDGEBIO ONCOLOG

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 11, 2025 BRIDGEBIO ONCOLOGY THERAPEUTICS, INC. (Exact name of registrant as specified in its charter) Delaware 001-41955 39-3690783 (State or other jurisdiction of incorporatio

INDEX TO UNAUDITED CONDENSED FINANCIAL STATEMENTS TheRas, Inc.

Exhibit 99.1 INDEX TO UNAUDITED CONDENSED FINANCIAL STATEMENTS TheRas, Inc. Page Unaudited Condensed Financial Statements: Unaudited Condensed Balance Sheets as of June 30, 2025 and December 31, 2024 F-2 Unaudited Condensed Statements of Operations for the three and six months ended June 30, 2025 and 2024 F-3 Unaudited Condensed Statements of Comprehensive Loss for the three and six months ended J

BridgeBio Oncology Therapeutics, INC. SENIOR EXECUTIVE CASH INCENTIVE BONUS PLAN

Exhibit 10.24 BridgeBio Oncology Therapeutics, INC. SENIOR EXECUTIVE CASH INCENTIVE BONUS PLAN 1. Purpose This Senior Executive Cash Incentive Bonus Plan (the “Incentive Plan”) is intended to provide an incentive for superior work and to motivate eligible executives of BridgeBio Oncology Therapeutics, Inc. (the “Company”) and its subsidiaries toward even higher achievement and business results, to

CERTIFICATE OF INCORPORATION BRIDGEBIO ONCOLOGY THERAPEUTICS, INC. ARTICLE I

Exhibit 3.1 CERTIFICATE OF INCORPORATION OF BRIDGEBIO ONCOLOGY THERAPEUTICS, INC. ARTICLE I The name of the Corporation is BridgeBio Oncology Therapeutics, Inc. ARTICLE II The address of the Corporation’s registered office in the State of Delaware is 1209 Orange Street, in the City of Wilmington, County of New Castle, 19801. The name of its registered agent at such address is The Corporation Trust

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Exhibit 10.13 September 10, 2024 Eli Wallace Re: TheRas, Inc. (dba BridgeBio Oncology Therapeutics) Equity Awards Dear Eli: This letter agreement (the “Agreement”) confirms the agreement between you and TheRas, Inc. (the “Company”) to amend the terms of the employment offer letter between you and the Company dated April 25, 2024 (the “Offer Letter”), effective as of the date first written above. C

MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS OF BBOT

Exhibit 99.3 MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS OF BBOT The following discussion and analysis of BBOT’s financial condition and results of operations of TheRas, Inc., d/b/a BridgeBio Oncology Therapeutics (for purposes of this section, “BBOT” “we” “our” or “us”) should be read together with BBOT’s audited annual financial statements for the years

BridgeBio Oncology Therapeutics, INC. NON-EMPLOYEE DIRECTOR COMPENSATION POLICY

Exhibit 10.25 BridgeBio Oncology Therapeutics, INC. NON-EMPLOYEE DIRECTOR COMPENSATION POLICY The purpose of this Non-Employee Director Compensation Policy (the “Policy”) of BridgeBio Oncology Therapeutics, Inc. (the “Company”) is to provide a total compensation package that enables the Company to attract and retain, on a long-term basis, high-caliber directors who are not employees or officers of

BRIDGEBIO ONCOLOGY THERAPEUTICS, INC. FORM OF INDEMNIFICATION AGREEMENT

Exhibit 10.26 BRIDGEBIO ONCOLOGY THERAPEUTICS, INC. FORM OF INDEMNIFICATION AGREEMENT This Indemnification Agreement (“Agreement”) is made as of [] by and between BridgeBio Oncology Therapeutics, Inc., a Delaware corporation (the “Company”), and [] (“Indemnitee”). RECITALS WHEREAS, the Company desires to attract and retain the services of highly qualified individuals, such as Indemnitee, to serve

AMENDED AND RESTATED REGISTRATION RIGHTS AGREEMENT

Exhibit 10.1 AMENDED AND RESTATED REGISTRATION RIGHTS AGREEMENT THIS AMENDED AND RESTATED REGISTRATION RIGHTS AGREEMENT (this “Agreement”), dated as of August 11, 2025, is made and entered into by and among BridgeBio Oncology Therapeutics, Inc., a Delaware corporation (the “Company”) (formerly known as Helix Acquisition Corp. II, a Cayman Islands exempted company, prior to its domestication as a D

BRIDGEBIO ONCOLOGY THERAPEUTICS, INC. Code of Business Conduct and Ethics

Exhibit 14.1 BRIDGEBIO ONCOLOGY THERAPEUTICS, INC. Code of Business Conduct and Ethics I. Purpose and Scope The Board of Directors of BridgeBio Oncology Therapeutics, Inc. (together with its subsidiaries, the “Company”) has adopted this Code of Business Conduct and Ethics (this “Code”) to aid the Company’s directors, officers and employees in making ethical and legal decisions when conducting the

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Exhibit 10.15 Yong Ben August 12, 2024 Re: Offer of Employment Dear Yong Ben On behalf of TheRas, Inc. (d/b/a BridgeBio Oncology Therapeutics) (the “Company”), I am pleased to confirm our offer to employ you as Chief Medical and Development Officer. The initial terms and conditions of your employment, should you accept this offer, are set forth below in this offer letter (this “Offer Letter”): 1.

August 12, 2025

Exhibit 16.1 August 12, 2025 Office of the Chief Accountant Securities and Exchange Commission 100 F Street, NE Washington, D.C. 20549 Ladies and Gentlemen: We have read the statements of BridgeBio Oncology Therapeutics, Inc. (the “Company”) included under Item 4.01 of its Form 8-K dated August 12, 2025. We agree with the statements concerning our Firm under Item 4.01, in which we were informed of

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Exhibit 10.16 August 11, 2025 Dr. Eli Wallace Re: Employment Agreement and Executive Severance Plan Participation Agreement Dear Eli: Reference is made to the Business Combination Agreement, dated as of February 28, 2025 (as amended, restated or otherwise modified from time to time, the “BCA”), entered into by and among TheRas, Inc., a Delaware corporation (“BBOT”), Helix Acquisition Corp. II, a C

AMENDED AND RESTATED BRIDGEBIO ONCOLOGY THERAPEUTICS, INC. (the “Corporation”) Article I Stockholders

Exhibit 3.2 AMENDED AND RESTATED BYLAWS OF BRIDGEBIO ONCOLOGY THERAPEUTICS, INC. (the “Corporation”) Article I Stockholders Section 1. Annual Meeting. The annual meeting of stockholders (any such meeting being referred to in these Bylaws as an “Annual Meeting”) shall be held at the hour, date and place within or without the United States that is fixed by or in the manner determined by the Board of

BRIDGEBIO ONCOLOGY THERAPEUTICS, Inc. Executive Severance Plan

Exhibit 10.23 BRIDGEBIO ONCOLOGY THERAPEUTICS, Inc. Executive Severance Plan 1. Purpose. BridgeBio Oncology Therapeutics, Inc. (the “Company”) considers it essential to the best interests of its stockholders to foster the continuous employment of key management personnel. The Board of Directors of the Company (the “Board”) recognizes, however, that, as is the case with many publicly-held corporati

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Exhibit 10.18 August 11, 2025 Dr. Yong Ben Re: Employment Agreement and Executive Severance Plan Participation Agreement Dear Yong: Reference is made to the Business Combination Agreement, dated as of February 28, 2025 (as amended, restated or otherwise modified from time to time, the “BCA”), entered into by and among TheRas, Inc., a Delaware corporation (“BBOT”), Helix Acquisition Corp. II, a Cay

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Exhibit 10.14 Pedro Beltran April 30, 2024 Re: Offer of Employment Dear Pedro On behalf of TheRas, Inc. (d/b/a BridgeBio Oncology Therapeutics) (the “Company”), I am pleased to confirm our offer to employ you as Chief Scientific Officer. The initial terms and conditions of your employment, should you accept this offer, are set forth below in this offer letter (this “Offer Letter”): 1. Position. As

BRIDGEBIO ONCOLOGY THERAPEUTICS, INC. 2025 STOCK OPTION AND INCENTIVE PLAN

Exhibit 10.21 BRIDGEBIO ONCOLOGY THERAPEUTICS, INC. 2025 STOCK OPTION AND INCENTIVE PLAN SECTION 1. GENERAL PURPOSE OF THE PLAN; DEFINITIONS The name of the plan is the BridgeBio Oncology Therapeutics, Inc. 2025 Stock Option and Incentive Plan (the “Plan”). The purpose of the Plan is to encourage and enable the officers, employees, Non-Employee Directors and Consultants of BridgeBio Oncology Thera

BRIDGEBIO ONCOLOGY THERAPEUTICS, INC. 2025 EMPLOYEE STOCK PURCHASE PLAN

Exhibit 10.22 BRIDGEBIO ONCOLOGY THERAPEUTICS, INC. 2025 EMPLOYEE STOCK PURCHASE PLAN The purpose of the BridgeBio Oncology Therapeutics, Inc. 2025 Employee Stock Purchase Plan (the “Plan”) is to provide eligible employees of BridgeBio Oncology Therapeutics, Inc. (the “Company”) and each Designated Company (as defined in Section 11) with opportunities to purchase shares of the Company’s common sto

LOCK-UP AGREEMENT

Exhibit 10.3 LOCK-UP AGREEMENT This Lock-Up Agreement (this “Agreement”) is dated as of August 11, 2025, by and among BridgeBio Oncology Therapeutics, Inc., a Delaware corporation (the “Company”) (formerly known as Helix Acquisition Corp. II, a Cayman Islands exempted company, prior to its domestication as a Delaware corporation), Helix Holdings II LLC, a Cayman Islands limited liability company (

LIST OF SUBSIDIARIES OF THE REGISTRANT

Exhibit 21.1 LIST OF SUBSIDIARIES OF THE REGISTRANT The following are the subsidiaries of BridgeBio Oncology Therapeutics, Inc.: Name State or Other Jurisdiction of Organization TheRas, Inc. DE

UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL INFORMATION

Exhibit 99.2 UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL INFORMATION Unless otherwise indicated or the context otherwise requires, references to: (a) “PubCo” refers to Helix and its consolidated subsidiaries after giving effect to the Business Combination, (b) “BBOT” refers to TheRas, Inc. (d/b/a BridgeBio Oncology Therapeutics), a Delaware corporation, prior to the Closing and (c) “Helix” re

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Exhibit 10.12 Eli Wallace April 30, 2024 Re: Offer of Employment Dear Eli On behalf of TheRas, Inc. (d/b/a BridgeBio Oncology Therapeutics) (the “Company”), I am pleased to confirm our offer to employ you as Chief Executive Officer. The initial terms and conditions of your employment, should you accept this offer, are set forth below in this offer letter (this “Offer Letter”): 1. Position. As Chie

BRIDGEBIO ONCOLOGY THERAPEUTICS, INC. FORM OF INDEMNIFICATION AGREEMENT

Exhibit 10.27 BRIDGEBIO ONCOLOGY THERAPEUTICS, INC. FORM OF INDEMNIFICATION AGREEMENT This Indemnification Agreement (“Agreement”) is made as of [] by and between BridgeBio Oncology Therapeutics, Inc., a Delaware corporation (the “Company”), and [] (“Indemnitee”). RECITALS WHEREAS, the Company desires to attract and retain the services of highly qualified individuals, such as Indemnitee, to serve

Helix Acquisition Corp. II Retains More than 60% of Trust Account after Redemptions in connection with Business Combination with BridgeBio Oncology Therapeutics

Exhibit 99.1 Helix Acquisition Corp. II Retains More than 60% of Trust Account after Redemptions in connection with Business Combination with BridgeBio Oncology Therapeutics ● Gross proceeds of approximately $120 million from trust account and approximately $261 million from PIPE financing to be available to the combined company at the closing ● 2nd lowest redemption rate for a biotech de-SPAC tra

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): August 6, 2025 HELIX ACQUISITION

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): August 6, 2025 HELIX ACQUISITION CORP. II (Exact name of registrant as specified in its charter) Cayman Islands 001-41955 N/A (State or other jurisdiction of incorporation) (Commissio

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): August 4, 2025 HELIX ACQUISITION

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): August 4, 2025 HELIX ACQUISITION CORP. II (Exact name of registrant as specified in its charter) Cayman Islands 001-41955 N/A (State or other jurisdiction of incorporation) (Commissio

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): August 4, 2025 HELIX ACQUISITION

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): August 4, 2025 HELIX ACQUISITION CORP. II (Exact name of registrant as specified in its charter) Cayman Islands 001-41955 N/A (State or other jurisdiction of incorporation) (Commissio

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (MARK ONE) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarter ended June 30, 2025 ☐ TRANSITION REPORT PURSUANT TO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (MARK ONE) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarter ended June 30, 2025 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-41955 HELIX ACQUISITION CORP

SUPPLEMENT TO PROXY STATEMENT FOR EXTRAORDINARY GENERAL MEETING OF SHAREHOLDERS OF HELIX ACQUISITION CORP. II (A CAYMAN ISLANDS EXEMPTED COMPANY) PROSPECTUS FOR UP TO 28,000,000 SHARES OF COMMON STOCK OF HELIX ACQUISITION CORP. II (WHICH WILL BE RENA

Filed Pursuant to Rule 424(b)(3) Registration No. 333-288222 Proxy Statement/Prospectus Supplement No. 1 (to the Proxy Statement/Prospectus dated July 10, 2025) SUPPLEMENT TO PROXY STATEMENT FOR EXTRAORDINARY GENERAL MEETING OF SHAREHOLDERS OF HELIX ACQUISITION CORP. II (A CAYMAN ISLANDS EXEMPTED COMPANY) AND PROSPECTUS FOR UP TO 28,000,000 SHARES OF COMMON STOCK OF HELIX ACQUISITION CORP. II (WHI

BBOT Appoints Industry Veteran Uneek Mehra as Chief Financial Officer Seasoned financial executive brings decades of strategic leadership and financial acumen across biotech and global healthcare to BBOT’s executive team

Filed by TheRas, Inc. Pursuant to Rule 425 under the Securities Act of 1933 and deemed filed pursuant to Rule 14a-12 of the Securities Exchange Act of 1934 Subject Company: Helix Acquisition Corp. II Commission File No. 001-41955 BBOT Appoints Industry Veteran Uneek Mehra as Chief Financial Officer Seasoned financial executive brings decades of strategic leadership and financial acumen across biot

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): July 11, 2025 HELIX ACQUISITION C

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): July 11, 2025 HELIX ACQUISITION CORP. II (Exact name of registrant as specified in its charter) Cayman Islands 001-41955 N/A (State or other jurisdiction of incorporation) (Commission

Helix Acquisition Corp. II and BridgeBio Oncology Therapeutics Announce Effectiveness of Registration Statement for Proposed Business Combination Extraordinary General Meeting of Helix Shareholders Scheduled for August 4, 2025

EX-99.1 2 ea024865501ex99-1helix2.htm PRESS RELEASE, DATED JULY 11, 2025 Exhibit 99.1 Helix Acquisition Corp. II and BridgeBio Oncology Therapeutics Announce Effectiveness of Registration Statement for Proposed Business Combination Extraordinary General Meeting of Helix Shareholders Scheduled for August 4, 2025 SOUTH SAN FRANCISCO & BOSTON, July 11, 2025 (GLOBE NEWSWIRE) - Helix Acquisition Corp.

Helix Acquisition Corp. II and BridgeBio Oncology Therapeutics Announce Effectiveness of Registration Statement for Proposed Business Combination Extraordinary General Meeting of Helix Shareholders Scheduled for August 4, 2025

Exhibit 99.1 Helix Acquisition Corp. II and BridgeBio Oncology Therapeutics Announce Effectiveness of Registration Statement for Proposed Business Combination Extraordinary General Meeting of Helix Shareholders Scheduled for August 4, 2025 SOUTH SAN FRANCISCO & BOSTON, July 11, 2025 (GLOBE NEWSWIRE) - Helix Acquisition Corp. II (“Helix”) (Nasdaq: HLXB), a special purpose acquisition company (“SPAC

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): July 11, 2025 HELIX ACQUISITION C

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): July 11, 2025 HELIX ACQUISITION CORP. II (Exact name of registrant as specified in its charter) Cayman Islands 001-41955 N/A (State or other jurisdiction of incorporation) (Commission

PROXY STATEMENT FOR EXTRAORDINARY GENERAL MEETING OF SHAREHOLDERS OF HELIX ACQUISITION CORP. II (A CAYMAN ISLANDS EXEMPTED COMPANY) PROSPECTUS FOR UP TO 28,000,000 SHARES OF COMMON STOCK OF HELIX ACQUISITION CORP. II (WHICH WILL BE RENAMED “BRIDGEBIO

Filed pursuant to Rule 424(b)(4) Registration No. 333-288222 PROXY STATEMENT FOR EXTRAORDINARY GENERAL MEETING OF SHAREHOLDERS OF HELIX ACQUISITION CORP. II (A CAYMAN ISLANDS EXEMPTED COMPANY) AND 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 DOMESTICATION IN THE STATE OF DELAWARE AND IN

As filed with the Securities and Exchange Commission on July 9, 2025.

As filed with the Securities and Exchange Commission on July 9, 2025. Registration No. 333-288222 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 AMENDMENT NO. 2 TO FORM S-4 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 HELIX ACQUISITION CORP. II* (Exact name of registrant as specified in its charter) Cayman Islands 6770 N/A (State or other jurisdiction of incorpo

As filed with the Securities and Exchange Commission on July 1, 2025.

As filed with the Securities and Exchange Commission on July 1, 2025. Registration No. 333-288222 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 AMENDMENT NO. 1 TO FORM S-4 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 HELIX ACQUISITION CORP. II* (Exact name of registrant as specified in its charter) Cayman Islands 6770 N/A (State or other jurisdiction of incorpo

Limited Exclusive Patent License Agreement, dated as of July 7, 2022, by and between BBOT and LLNS

Exhibit 10.16 CERTAIN INFORMATION CONTAINED IN THIS EXHIBIT, MARKED BY [***], HAS BEEN EXCLUDED FROM THIS EXHIBIT BECAUSE THE REGISTRANT HAS DETERMINED THAT IT IS BOTH NOT MATERIAL AND IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. EXCLUSIVE PATENT LICENSE AGREEMENT For KRAS G12C INHIBITORS Between LAWRENCE LIVERMORE NATIONAL SECURITY, LLC and THERAS, INC. LLNL Case No. TL02796

Form of Employment Agreement by and between the Registrant and Eli Wallace.

Exhibit 10.22 June , 2025 Dr. Eli Wallace Re: Employment Agreement and Executive Severance Plan Participation Agreement Dear Eli: Reference is made to the Business Combination Agreement, dated as of February 28, 2025 (as amended, restated or otherwise modified from time to time, the “BCA”), entered into by and among TheRas, Inc., a Delaware corporation (“BBOT”), Helix Acquisition Corp. II, a Cayma

Cooperative Research and Development Agreement (“Agreement”), dated March 3, 2017, between Frederick National Laboratory for Cancer Research (FNLCR) Operated by Leidos Biomedical Research, Inc. (“Leidos”) and BBOT, as amended by Amendment No. 1 to Agreement dated January 19, 2018, by and between Leidos and BBOT, as further amended by Amendment No. 2 to Agreement dated January 2, 2019, by and between Leidos and BBOT, as further amended by Amendment No. 3 to Agreement dated November 14, 2019, by and between Leidos and BBOT, as further amended by Amendment No. 4 to Agreement dated January 13, 2020, by and between Leidos and BBOT, as further amended by Amendment No. 5 to Agreement dated September 22, 2021, by and between Leidos and BBOT, as further amended by Amendment No. 6 to Agreement dated March 27, 2023, by and between Leidos and BBOT, as further amended by Amendment No. 7 to Agreement dated August 20, 2024, by and between Leidos and BBOT.

Exhibit 10.21 CERTAIN INFORMATION CONTAINED IN THIS EXHIBIT, MARKED BY [***], HAS BEEN EXCLUDED FROM THIS EXHIBIT BECAUSE THE REGISTRANT HAS DETERMINED THAT IT IS BOTH NOT MATERIAL AND IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. LEIDOS BIOMEDICAL COOPERATIVE RESEARCH AND DEVELOPMENT AGREEMENT This Cooperative Research and Development Agreement (“CRADA” or “Agreement”) has be

Patent License Agreement, dated as of December 20, 2023, by and between BBOT and The Frederick National Laboratory for Cancer Research, operated by Leidos Biomedical Research, Inc.

Exhibit 10.20 CERTAIN INFORMATION CONTAINED IN THIS EXHIBIT, MARKED BY [***], HAS BEEN EXCLUDED FROM THIS EXHIBIT BECAUSE THE REGISTRANT HAS DETERMINED THAT IT IS BOTH NOT MATERIAL AND IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. PATENT LICENSE AGREEMENT — EXCLUSIVE This Cover Page identifies the Parties to this Agreement: The Frederick National Laboratory for Cancer Research

Form of Employment Agreement by and between the Registrant and Pedro Beltran.

Exhibit 10.23 June , 2025 Dr. Pedro Beltran Re: Employment Agreement and Executive Severance Plan Participation Agreement Dear Pedro: Reference is made to the Business Combination Agreement, dated as of February 28, 2025 (as amended, restated or otherwise modified from time to time, the “BCA”), entered into by and among TheRas, Inc., a Delaware corporation (“BBOT”), Helix Acquisition Corp. II, a C

Limited Exclusive Patent License Agreement, dated as of July 7, 2022, by and between BBOT and LLNS

Exhibit 10.15 CERTAIN INFORMATION CONTAINED IN THIS EXHIBIT, MARKED BY [***], HAS BEEN EXCLUDED FROM THIS EXHIBIT BECAUSE THE REGISTRANT HAS DETERMINED THAT IT IS BOTH NOT MATERIAL AND IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. EXCLUSIVE PATENT LICENSE AGREEMENT For PI3Kα BREAKERS Between LAWRENCE LIVERMORE NATIONAL SECURITY, LLC and THERAS, INC. LLNL Case No. TL02797 Lawre

Stevenson-Wydler (15 USC 3710a) Cooperative Research and Development Agreement, dated as of May 22, 2018, by and between Lawrence Livermore National Security, LLC (the “LLNS”) and BBOT, as amended by that certain Amendment No. 1 to the Cooperative Research and Development Agreement, dated as of December 2, 2019, by and between LLNS and BBOT, as further amended by that certain Amendment No. 2 to the Cooperative Research and Development Agreement, dated as of May 21, 2021, by and between LLNS and BBOT, as further amended by that certain Amendment No. 3 to the Cooperative Research and Development Agreement, dated as of June 22, 2022, by and between LLNS and BBOT, as further amended by that certain Amendment No. 4 to the Cooperative Research and Development Agreement, dated as of December 21, 2023, by and between LLNS and BBOT, as further amended by that certain Amendment No. 5 to the Cooperative Research and Development Agreement, dated as of May 20, 2025, by and between LLNS and BBOT.

Exhibit 10.14 CERTAIN INFORMATION CONTAINED IN THIS EXHIBIT, MARKED BY [***], HAS BEEN EXCLUDED FROM THIS EXHIBIT BECAUSE THE REGISTRANT HAS DETERMINED THAT IT IS BOTH NOT MATERIAL AND IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. STEVENSON-WYDLER (15 USC 3710a) COOPERATIVE RESEARCH AND DEVELOPMENT AGREEMENT Between LAWRENCE LIVERMORE NATIONAL SECURITY, LLC and THERAS, INC. Fo

Calculation of Registration Fee Table.

Exhibit 107 Calculation of Filing Fee Tables Form S-4 (Form Type) HELIX ACQUISITION CORP.

Form of Certificate of Domestication of Helix Acquisition Corp. II.

Exhibit 3.4 CERTIFICATE OF DOMESTICATION OF HELIX ACQUISITION CORP. II Pursuant to Sections 103 and 388 of the General Corporation Law of the State of Delaware Helix Acquisition Corp. II, a Cayman Islands exempted company limited by its shares (the “Corporation”), which intends to domesticate as a Delaware corporation pursuant to this Certificate of Domestication, does hereby certify to the follow

Consent of Lincoln International LLC.

Exhibit 99.1 June 20, 2025 The Transaction Committee of the Board of Directors of Helix Acquisition Corp. II 200 Clarendon Street Boston, MA 02116 Re: Registration Statement on Form S-4 of Helix Acquisition Corp. II (the “Registration Statement”) Members of the Transaction Committee: Reference is made to our opinion letter, dated February 27, 2025 (the “Opinion”), with respect to the fairness, fro

As filed with the Securities and Exchange Commission on June 20, 2025.

As filed with the Securities and Exchange Commission on June 20, 2025. Registration No. 333-[•] UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-4 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 HELIX ACQUISITION CORP. II* (Exact name of registrant as specified in its charter) Cayman Islands 6770 N/A (State or other jurisdiction of incorporation or organizatio

Limited Exclusive Patent License Agreement, dated as of December 20, 2024, by and between BBOT and LLNS

Exhibit 10.17 CERTAIN INFORMATION CONTAINED IN THIS EXHIBIT, MARKED BY [***], HAS BEEN EXCLUDED FROM THIS EXHIBIT BECAUSE THE REGISTRANT HAS DETERMINED THAT IT IS BOTH NOT MATERIAL AND IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. EXCLUSIVE PATENT LICENSE AGREEMENT For PAN-KRAS INHIBITORS Between LAWRENCE LIVERMORE NATIONAL SECURITY, LLC and THERAS, INC. LLNL Case No. 2025-012

Patent License Agreement, dated as of August 5, 2022, by and between BBOT and The Frederick National Laboratory for Cancer Research, operated by Leidos Biomedical Research, Inc.

Exhibit 10.18 CERTAIN INFORMATION CONTAINED IN THIS EXHIBIT, MARKED BY [***], HAS BEEN EXCLUDED FROM THIS EXHIBIT BECAUSE THE REGISTRANT HAS DETERMINED THAT IT IS BOTH NOT MATERIAL AND IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. PATENT LICENSE AGREEMENT — EXCLUSIVE This Cover Page identifies the Parties to this Agreement: The Frederick National Laboratory for Cancer Research

Specimen Common Stock Certificate of BridgeBio Oncology Therapeutics, Inc.

Exhibit 4.1 BRIDGEBIO ONCOLOGY THERAPEUTICS, INC. INCORPORATED UNDER THE LAWS OF THE STATE OF DELAWARE COMMON STOCK This Certifies that is the owner of FULLY PAID AND NON-ASSESSABLE SHARES OF COMMON STOCK, PAR VALUE OF $0.0001 PER SHARE, OF BRIDGEBIO ONCOLOGY THERAPEUTICS, INC. (THE “COMPANY”) transferable on the books of the Company in person or by duly authorized attorney upon surrender of this

Form of Executive Severance Plan.

Exhibit 10.25 BRIDGEBIO ONCOLOGY THERAPEUTICS, Inc. Executive Severance Plan 1. Purpose. BridgeBio Oncology Therapeutics, Inc. (the “Company”) considers it essential to the best interests of its stockholders to foster the continuous employment of key management personnel. The Board of Directors of the Company (the “Board”) recognizes, however, that, as is the case with many publicly-held corporati

Opinion of Goodwin Procter LLP regarding U.S. federal income tax matters.

Exhibit 8.3 June 20, 2025 TheRas Inc. 1 Corporate Drive South San Francisco, CA 94080 Ladies and Gentlemen: This opinion is delivered to you in our capacity as counsel to TheRas. Inc, a Delaware corporation (the “Company”), in connection with the merger (the “Merger”) of Helix II Merger Sub, Inc., a Delaware corporation (“Merger Sub”) with and into the Company, with the Company surviving, pursuant

Form of Employment Agreement by and between the Registrant and Yong Ben.

Exhibit 10.24 June , 2025 Dr. Yong Ben Re: Employment Agreement and Executive Severance Plan Participation Agreement Dear Yong: Reference is made to the Business Combination Agreement, dated as of February 28, 2025 (as amended, restated or otherwise modified from time to time, the “BCA”), entered into by and among TheRas, Inc., a Delaware corporation (“BBOT”), Helix Acquisition Corp. II, a Cayman

Patent License Agreement, dated as of August 5, 2022, by and between BBOT and The Frederick National Laboratory for Cancer Research, operated by Leidos Biomedical Research, Inc.

Exhibit 10.19 CERTAIN INFORMATION CONTAINED IN THIS EXHIBIT, MARKED BY [***], HAS BEEN EXCLUDED FROM THIS EXHIBIT BECAUSE THE REGISTRANT HAS DETERMINED THAT IT IS BOTH NOT MATERIAL AND IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. PATENT LICENSE AGREEMENT — EXCLUSIVE This Cover Page identifies the Parties to this Agreement: The Frederick National Laboratory for Cancer Research

LEIDOS BIOMEDICAL COOPERATIVE RESEARCH AND DEVELOPMENT AGREEMENT

Exhibit 10.21 CERTAIN INFORMATION CONTAINED IN THIS EXHIBIT, MARKED BY [***], HAS BEEN EXCLUDED FROM THIS EXHIBIT BECAUSE THE REGISTRANT HAS DETERMINED THAT IT IS BOTH NOT MATERIAL AND IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. LEIDOS BIOMEDICAL COOPERATIVE RESEARCH AND DEVELOPMENT AGREEMENT This Cooperative Research and Development Agreement (“CRADA” or “Agreement”) has be

STEVENSON-WYDLER (15 USC 3710a) COOPERATIVE RESEARCH AND DEVELOPMENT AGREEMENT LAWRENCE LIVERMORE NATIONAL SECURITY, LLC THERAS, INC. DISCOVERY OF NOVEL RAS INHIBITORS LLNL Case No. TC02290.0 Lawrence Livermore National Laboratory Lawrence Livermore

Exhibit 10.14 CERTAIN INFORMATION CONTAINED IN THIS EXHIBIT, MARKED BY [***], HAS BEEN EXCLUDED FROM THIS EXHIBIT BECAUSE THE REGISTRANT HAS DETERMINED THAT IT IS BOTH NOT MATERIAL AND IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. STEVENSON-WYDLER (15 USC 3710a) COOPERATIVE RESEARCH AND DEVELOPMENT AGREEMENT Between LAWRENCE LIVERMORE NATIONAL SECURITY, LLC and THERAS, INC. Fo

PATENT LICENSE AGREEMENT — EXCLUSIVE This Cover Page identifies the Parties to this Agreement: The Frederick National Laboratory for Cancer Research, operated by Leidos Biomedical Research, Inc (hereinafter referred to as “Leidos Biomedical”) THERAS,

Exhibit 10.19 CERTAIN INFORMATION CONTAINED IN THIS EXHIBIT, MARKED BY [***], HAS BEEN EXCLUDED FROM THIS EXHIBIT BECAUSE THE REGISTRANT HAS DETERMINED THAT IT IS BOTH NOT MATERIAL AND IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. PATENT LICENSE AGREEMENT — EXCLUSIVE This Cover Page identifies the Parties to this Agreement: The Frederick National Laboratory for Cancer Research

EXCLUSIVE PATENT LICENSE AGREEMENT PI3Kα BREAKERS LAWRENCE LIVERMORE NATIONAL SECURITY, LLC THERAS, INC. LLNL Case No. TL02797 Lawrence Livermore National Laboratory Innovation and Partnerships Office P.O. Box 808, L-779 Livermore, CA 94551 TABLE OF

Exhibit 10.15 CERTAIN INFORMATION CONTAINED IN THIS EXHIBIT, MARKED BY [***], HAS BEEN EXCLUDED FROM THIS EXHIBIT BECAUSE THE REGISTRANT HAS DETERMINED THAT IT IS BOTH NOT MATERIAL AND IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. EXCLUSIVE PATENT LICENSE AGREEMENT For PI3Kα BREAKERS Between LAWRENCE LIVERMORE NATIONAL SECURITY, LLC and THERAS, INC. LLNL Case No. TL02797 Lawre

As confidentially submitted to the Securities and Exchange Commission on May 30, 2025. This Amendment No. 1 to Draft Registration Statement has not been filed publicly with the Securities and Exchange Commission and all information contained herein r

As confidentially submitted to the Securities and Exchange Commission on May 30, 2025.

PATENT LICENSE AGREEMENT — EXCLUSIVE This Cover Page identifies the Parties to this Agreement: The Frederick National Laboratory for Cancer Research, operated by Leidos Biomedical Research, Inc (hereinafter referred to as “Leidos Biomedical”) THERAS,

Exhibit 10.18 CERTAIN INFORMATION CONTAINED IN THIS EXHIBIT, MARKED BY [***], HAS BEEN EXCLUDED FROM THIS EXHIBIT BECAUSE THE REGISTRANT HAS DETERMINED THAT IT IS BOTH NOT MATERIAL AND IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. PATENT LICENSE AGREEMENT — EXCLUSIVE This Cover Page identifies the Parties to this Agreement: The Frederick National Laboratory for Cancer Research

PATENT LICENSE AGREEMENT KRAS G12C INHIBITORS LAWRENCE LIVERMORE NATIONAL SECURITY, LLC THERAS, INC. LLNL Case No. TL02796 Lawrence Livermore National Laboratory Innovation and Partnerships Office P.O. Box 808, L-779 Livermore, CA 94551 TABLE OF CONT

Exhibit 10.16 CERTAIN INFORMATION CONTAINED IN THIS EXHIBIT, MARKED BY [***], HAS BEEN EXCLUDED FROM THIS EXHIBIT BECAUSE THE REGISTRANT HAS DETERMINED THAT IT IS BOTH NOT MATERIAL AND IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. EXCLUSIVE PATENT LICENSE AGREEMENT For KRAS G12C INHIBITORS Between LAWRENCE LIVERMORE NATIONAL SECURITY, LLC and THERAS, INC. LLNL Case No. TL02796

EXCLUSIVE PATENT LICENSE AGREEMENT PAN-KRAS INHIBITORS LAWRENCE LIVERMORE NATIONAL SECURITY, LLC THERAS, INC. LLNL Case No. 2025-0121 Lawrence Livermore National Laboratory Innovation and Partnerships Office P.O. Box 808, L-778 Livermore, CA 94551 TA

Exhibit 10.17 CERTAIN INFORMATION CONTAINED IN THIS EXHIBIT, MARKED BY [***], HAS BEEN EXCLUDED FROM THIS EXHIBIT BECAUSE THE REGISTRANT HAS DETERMINED THAT IT IS BOTH NOT MATERIAL AND IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. EXCLUSIVE PATENT LICENSE AGREEMENT For PAN-KRAS INHIBITORS Between LAWRENCE LIVERMORE NATIONAL SECURITY, LLC and THERAS, INC. LLNL Case No. 2025-012

PATENT LICENSE AGREEMENT — EXCLUSIVE This Cover Page identifies the Parties to this Agreement: The Frederick National Laboratory for Cancer Research, operated by Leidos Biomedical Research, Inc. (hereinafter referred to as “Leidos Biomedical”) THERAS

Exhibit 10.20 CERTAIN INFORMATION CONTAINED IN THIS EXHIBIT, MARKED BY [***], HAS BEEN EXCLUDED FROM THIS EXHIBIT BECAUSE THE REGISTRANT HAS DETERMINED THAT IT IS BOTH NOT MATERIAL AND IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. PATENT LICENSE AGREEMENT — EXCLUSIVE This Cover Page identifies the Parties to this Agreement: The Frederick National Laboratory for Cancer Research

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (MARK ONE) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarter ended March 31, 2025 ☐ TRANSITION REPORT PURSUANT T

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (MARK ONE) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarter ended March 31, 2025 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-41955 HELIX ACQUISITION COR

As confidentially submitted to the Securities and Exchange Commission on April 14, 2025. This Draft Registration Statement has not been filed publicly with the Securities and Exchange Commission and all information contained herein remains confidenti

As confidentially submitted to the Securities and Exchange Commission on April 14, 2025.

Code of Business Conduct and Ethics.

Exhibit 14 HELIX ACQUISITION CORP. II FORM OF CODE OF BUSINESS CONDUCT AND ETHICS Effective of February 8, 2024 I. Introduction The Board of Directors (the “Board”) of Helix Acquisition Corp. II has adopted this code of business conduct and ethics (this “Code”), as amended from time to time by the Board and which is applicable to all of the Company’s directors, officers and employees (to the exten

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 ☐ TRANSITION REPORT PURSUANT TO SECTI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM TO COMMISSION FILE NUMBER 001-41955 HELIX ACQUISITION CORP. II

Policy relating to recovery of erroneously awarded compensation, as required by applicable listing standards adopted pursuant to 17 CFR 240.10D-1.

Exhibit 97.1 HELIX ACQUISITION CORP. II POLICY FOR THE RECOVERY OF ERRONEOUSLY AWARDED COMPENSATION A. OVERVIEW In accordance with the applicable rules of The Nasdaq Stock Market (the “Nasdaq Rules”), Section 10D and Rule 10D-1 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) (“Rule 10D-1”), the Board of Directors (the “Board”) of Helix Acquisition Corp. II (the “Company”) h

Description of Registrant’s Securities.

Exhibit 4.2 DESCRIPTION OF THE REGISTRANT’S SECURITIES The following description of Helix Acquisition Corp. II’s (the “Company,” “we” or “us”) securities is a summary and does not purport to be complete. It is subject to and qualified in its entirety by reference to the Company’s amended and restated memorandum and articles of association, which is incorporated by reference as an exhibit to the An

Insider Trading Policy

Exhibit 19 HELIX ACQUISITION CORP. II POLICY REGARDING INSIDER TRADING AND DISSEMINATION OF INSIDE INFORMATION Effective February 8, 2024 I. INTRODUCTION This Policy Regarding Insider Trading and Dissemination of Inside Information (this “Policy”) describes the policy of Helix Acquisition Corp. II (the “Company”) regarding: ● the trading of securities while you are in possession of Inside Informat

2

Filed by TheRas, Inc. Pursuant to Rule 425 under the Securities Act of 1933 and deemed filed pursuant to Rule 14a-12 of the Securities Exchange Act of 1934 Subject Company: Helix Acquisition Corp. II Commission File No. 001-41955 The following social media post was uploaded to LinkedIn platform by TheRas, Inc. Additional Information and Where to Find It This communication relates to the business c

Form of Non-Redemption Agreement (incorporated by reference to Exhibit 10.4 to the Company’s Current Report on Form 8-K, filed with the Securities and Exchange Commission on March 3, 2025).

Exhibit 10.4 FORM OF NON-REDEMPTION AGREEMENT THIS NON-REDEMPTION AGREEMENT (this “Agreement”), dated as of , 2025, is made by and between Helix Acquisition Corp. II, a Cayman Islands exempted company (the “Company”), and the undersigned shareholder (the “Holder”). RECITALS WHEREAS, substantially concurrently with the execution of this Agreement, the Company is entering into a business combination

Form of Lock-Up Agreement.

Exhibit 10.5 LOCK-UP AGREEMENT This Lock-Up Agreement (this “Agreement”) is dated as of [●], 2025, by and among [●], a Delaware corporation (the “Company”) (formerly known as Helix Acquisition Corp. II, a Cayman Islands exempted company, prior to its domestication as a Delaware corporation), Helix Holdings II LLC, a Cayman Islands limited liability company (the “Sponsor”), certain investment vehic

BBOT Support Agreement, dated as of February 28, 2025 (incorporated by reference to Exhibit 10.2 to the Company’s Current Report on Form 8-K, filed with the Securities and Exchange Commission on March 3, 2025).

Exhibit 10.2 COMPANY SUPPORT AGREEMENT This COMPANY SUPPORT AGREEMENT (this “Agreement”), dated as of February 28, 2025, is made by and among Helix Acquisition Corp. II., a Cayman Islands exempted company (“Parent”), TheRas, Inc., a Delaware corporation (the “Company”) and the undersigned stockholder of the Company (the “Stockholder”). Parent, Company and Stockholder shall be referred to herein fr

Form of Subscription Agreement (incorporated by reference to Exhibit 10.3 to the Company’s Current Report on Form 8-K, filed with the Securities and Exchange Commission on March 3, 2025).

Exhibit 10.3 FORM OF SUBSCRIPTION AGREEMENT This SUBSCRIPTION AGREEMENT (this “Subscription Agreement”) is entered into on [●], 2025 by and between Helix Acquisition Corp. II, a Cayman Islands exempted company (the “Company”), and [each of] the subscriber part[y][ies] set forth on the signature page hereto ([each a/the] “Subscriber”). RECITALS WHEREAS, substantially concurrently with the execution

Business Combination Agreement, by and among Helix Acquisition Corp. II, TheRas, Inc. and Helix II Merger Sub, Inc., dated as of February 28, 2025. (incorporated by reference to Exhibit 2.1 to the Company’s Current Report on Form 8-K, filed with the Securities and Exchange Commission on March 3, 2025).

Exhibit 2.1 BUSINESS COMBINATION AGREEMENT dated February 28, 2025 by and among TheRas, Inc., Helix Acquisition Corp. II, and Helix II Merger Sub, Inc. TABLE OF CONTENTS Page ARTICLE I DEFINITIONS 3 1.1 Certain Definitions 3 1.2 Further Definitions 14 1.3 Construction 17 ARTICLE II THE DOMESTICATION AND THE MERGER 18 2.1 The Domestication 18 2.2 The Merger 19 2.3 Closing 19 2.4 Directors and Offic

Business Combination Agreement, by and among Helix Acquisition Corp. II, TheRas, Inc. and Helix II Merger Sub, Inc., dated as of February 28, 2025.

Exhibit 2.1 BUSINESS COMBINATION AGREEMENT dated February 28, 2025 by and among TheRas, Inc., Helix Acquisition Corp. II, and Helix II Merger Sub, Inc. TABLE OF CONTENTS Page ARTICLE I DEFINITIONS 3 1.1 Certain Definitions 3 1.2 Further Definitions 14 1.3 Construction 17 ARTICLE II THE DOMESTICATION AND THE MERGER 18 2.1 The Domestication 18 2.2 The Merger 19 2.3 Closing 19 2.4 Directors and Offic

Form of Amended and Restated Registration Rights Agreement.

Exhibit 10.6 FORM OF AMENDED AND RESTATED REGISTRATION RIGHTS AGREEMENT THIS AMENDED AND RESTATED REGISTRATION RIGHTS AGREEMENT (this “Agreement”), dated as of [●], 2025, is made and entered into by and among [●], a Delaware corporation (the “Company”) (formerly known as Helix Acquisition Corp. II, a Cayman Islands exempted company, prior to its domestication as a Delaware corporation), Helix Hold

Entry into a Material Definitive Agreement, Unregistered Sales of Equity Securities, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): February 28, 2025 HELIX ACQUISITION CORP. II (Exact name of registrant as specified in its charter) Cayman Islands 001-41955 N/A (State or other jurisdiction (Commission File Number)

BBOT Support Agreement, dated as of February 28, 2025.

Exhibit 10.2 COMPANY SUPPORT AGREEMENT This COMPANY SUPPORT AGREEMENT (this “Agreement”), dated as of February 28, 2025, is made by and among Helix Acquisition Corp. II., a Cayman Islands exempted company (“Parent”), TheRas, Inc., a Delaware corporation (the “Company”) and the undersigned stockholder of the Company (the “Stockholder”). Parent, Company and Stockholder shall be referred to herein fr

Helix Support Agreement, dated as of February 28, 2025 (incorporated by reference to Exhibit 10.1 to the Company’s Current Report on Form 8-K, filed with the Securities and Exchange Commission on March 3, 2025).

Exhibit 10.1 PARENT SUPPORT AGREEMENT This Parent Support Agreement (“Support Agreement”) is dated as of 28, 2025, by and among (i) Helix Acquisition Corp. II, a Cayman Islands exempted company (which shall domesticate as a Delaware corporation one Business Day prior to the Closing) (“Parent”); (ii) Theras, Inc., a Delaware corporation (d/b/a BridgeBio Oncology Therapeutics) (“Company”); (iii) Hel

Form of Non-Redemption Agreement.

Exhibit 10.4 FORM OF NON-REDEMPTION AGREEMENT THIS NON-REDEMPTION AGREEMENT (this “Agreement”), dated as of , 2025, is made by and between Helix Acquisition Corp. II, a Cayman Islands exempted company (the “Company”), and the undersigned shareholder (the “Holder”). RECITALS WHEREAS, substantially concurrently with the execution of this Agreement, the Company is entering into a business combination

Form of Amended and Restated Registration Rights Agreement.

Exhibit 10.6 FORM OF AMENDED AND RESTATED REGISTRATION RIGHTS AGREEMENT THIS AMENDED AND RESTATED REGISTRATION RIGHTS AGREEMENT (this “Agreement”), dated as of [●], 2025, is made and entered into by and among [●], a Delaware corporation (the “Company”) (formerly known as Helix Acquisition Corp. II, a Cayman Islands exempted company, prior to its domestication as a Delaware corporation), Helix Hold

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): February 28, 2025 HELIX ACQUISITI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): February 28, 2025 HELIX ACQUISITION CORP. II (Exact name of registrant as specified in its charter) Cayman Islands 001-41955 N/A (State or other jurisdiction (Commission File Number)

Form of Subscription Agreement.

Exhibit 10.3 FORM OF SUBSCRIPTION AGREEMENT This SUBSCRIPTION AGREEMENT (this “Subscription Agreement”) is entered into on [●], 2025 by and between Helix Acquisition Corp. II, a Cayman Islands exempted company (the “Company”), and [each of] the subscriber part[y][ies] set forth on the signature page hereto ([each a/the] “Subscriber”). RECITALS WHEREAS, substantially concurrently with the execution

Helix Support Agreement, dated as of February 28, 2025.

Exhibit 10.1 PARENT SUPPORT AGREEMENT This Parent Support Agreement (“Support Agreement”) is dated as of 28, 2025, by and among (i) Helix Acquisition Corp. II, a Cayman Islands exempted company (which shall domesticate as a Delaware corporation one Business Day prior to the Closing) (“Parent”); (ii) Theras, Inc., a Delaware corporation (d/b/a BridgeBio Oncology Therapeutics) (“Company”); (iii) Hel

Form of Lock-Up Agreement.

Exhibit 10.5 LOCK-UP AGREEMENT This Lock-Up Agreement (this “Agreement”) is dated as of [●], 2025, by and among [●], a Delaware corporation (the “Company”) (formerly known as Helix Acquisition Corp. II, a Cayman Islands exempted company, prior to its domestication as a Delaware corporation), Helix Holdings II LLC, a Cayman Islands limited liability company (the “Sponsor”), certain investment vehic

2

Exhibit 99.1 BridgeBio Oncology Therapeutics (BBOT) and Helix Acquisition Corp. II Announce Business Combination Agreement to Create Publicly Listed Biotechnology Company Advancing a Pipeline of RAS and PI3Kα-Targeting Medicines ● Total proceeds, assuming no redemptions, are expected to be $450 million, combining funds held in the Helix Acquisition Corp. II trust account and a private investment i

Q1 2025 BridgeBio Oncology Therapeutics Confidential overview Disclaimer (1 of 3) 2 Confidential and proprietary. Do not duplicate without permission from BridgeBio Oncology Therapeutics. This presentation (together with oral statements made in conne

Exhibit 99.2 Q1 2025 BridgeBio Oncology Therapeutics Confidential overview Disclaimer (1 of 3) 2 Confidential and proprietary. Do not duplicate without permission from BridgeBio Oncology Therapeutics. This presentation (together with oral statements made in connection herewith, this “Presentation”) is for informational purposes only . This Presentation has been prepared to assist interested partie

2

Exhibit 99.1 BridgeBio Oncology Therapeutics (BBOT) and Helix Acquisition Corp. II Announce Business Combination Agreement to Create Publicly Listed Biotechnology Company Advancing a Pipeline of RAS and PI3Kα-Targeting Medicines ● Total proceeds, assuming no redemptions, are expected to be $450 million, combining funds held in the Helix Acquisition Corp. II trust account and a private investment i

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): February 28, 2025 HELIX ACQUISITI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): February 28, 2025 HELIX ACQUISITION CORP. II (Exact name of registrant as specified in its charter) Cayman Islands 001-41955 N/A (State or other jurisdiction (Commission File Number)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): February 28, 2025 HELIX ACQUISITI

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): February 28, 2025 HELIX ACQUISITION CORP. II (Exact name of registrant as specified in its charter) Cayman Islands 001-41955 N/A (State or other jurisdiction (Commission File Number)

Q1 2025 BridgeBio Oncology Therapeutics Confidential overview Disclaimer (1 of 3) 2 Confidential and proprietary. Do not duplicate without permission from BridgeBio Oncology Therapeutics. This presentation (together with oral statements made in conne

Exhibit 99.2 Q1 2025 BridgeBio Oncology Therapeutics Confidential overview Disclaimer (1 of 3) 2 Confidential and proprietary. Do not duplicate without permission from BridgeBio Oncology Therapeutics. This presentation (together with oral statements made in connection herewith, this “Presentation”) is for informational purposes only . This Presentation has been prepared to assist interested partie

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): February 8, 2025 HELIX ACQUISITION CORP. II (Exact name of registrant as specified in its charter) Cayman Islands 001-41955 N/A (State or other jurisdiction (Commission File Number) (

Letter Agreement, dated February 8, 2025, between Helix Acquisition Corp. II and Albert A. Holman III (incorporated by reference to Exhibit 10.1 to Helix’s Current Report on Form 8-K (File No. 001-41955), filed with the SEC on February 10, 2025).

Exhibit 10.1 February 8, 2025 Helix Acquisition Corp. II c/o Cormorant Asset Management, LP 200 Clarendon Street, 52nd Floor Boston, MA 02116 Re: Initial Public Offering Ladies and Gentlemen: This letter (this “Letter Agreement”) is being delivered to you in accordance with the Underwriting Agreement (the “Underwriting Agreement”) entered into by and among Helix Acquisition Corp. II, a Cayman Isla

Joinder Agreement, dated February 8, 2025, by and between the Company and Albert A. Holman, III (incorporated by reference to Exhibit 10.2 to Helix’s Current Report on Form 8-K (File No. 001-41955), filed with the SEC on February 10, 2025).

Exhibit 10.2 JOINDER AGREEMENT February 8, 2025 By executing this joinder, the undersigned hereby agrees, as of the date first set forth above, that the undersigned shall become a party to that certain Registration Rights Agreement, dated February 8, 2024 (as may be amended or restated from time to time, the “Registration Rights Agreement”), by and among Helix Acquisition Corp. II, Helix Holdings

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (MARK ONE) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarter ended September 30, 2024 ☐ TRANSITION REPORT PURSUA

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (MARK ONE) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarter ended September 30, 2024 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-41955 HELIX ACQUISITION

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (MARK ONE) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarter ended June 30, 2024 ☐ TRANSITION REPORT PURSUANT TO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (MARK ONE) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarter ended June 30, 2024 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-41955 HELIX ACQUISITION CORP

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (MARK ONE) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarter ended March 31, 2024 ☐ TRANSITION REPORT PURSUANT T

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (MARK ONE) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarter ended March 31, 2024 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number: 001-41955 HELIX ACQUISITION COR

HLXB / Helix Acquisition Corp. II / ADAGE CAPITAL PARTNERS GP, L.L.C. - HELIX ACQUISITION CORP. II Passive Investment

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* Helix Acquisition Corp. II (Name of Issuer) Class A Ordinary Shares, par value $0.0001 per share (Title of Class of Securities) G4444H101 (CUSIP Number) February 13, 2024 (Date of Event Which Requires Filing of This Statement) Check the appropriate box to designate the

HLXB / Helix Acquisition Corp. II / CITADEL ADVISORS LLC - SC 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G* (Rule 13d-102) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO § 240.13d-1(b), (c), AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO § 240.13d-2 (Amendment No. )* Helix Acquisition Corp. II (Name of Issuer) Class A ordinary share, par value $0.0001 per share (the “Shares”) (Title of Class of Securities

JOINT FILING AGREEMENT

EX-99.1 2 tm247132d1ex99-1.htm EXHIBIT 99.1 EXHIBIT 99.1 JOINT FILING AGREEMENT The undersigned hereby agree that the Statement on Schedule 13G filed herewith (and any amendments thereto), relating to the Shares of Helix Acquisition Corp. II, a Cayman Islands exempted company, is being filed jointly with the Securities and Exchange Commission pursuant to Rule 13d-1(c) under the Securities Exchange

Joint Filing Agreement.

EX-99.1 2 ea0200275ex99-1helix2.htm JOINT FILING AGREEMENT Exhibit 1 JOINT FILING AGREEMENT February 20, 2024 Pursuant to and in accordance with the Securities Exchange Act of 1934, as amended, and the rules and regulations thereunder (the “Exchange Act”) the undersigned hereby agree to the joint filing on behalf of each of them of any filing required by such party under Section 13 of the Exchange

HELIX ACQUISITION CORP. II INDEX TO FINANCIAL STATEMENT

Exhibit 99.1 HELIX ACQUISITION CORP. II INDEX TO FINANCIAL STATEMENT Page Report of Independent Registered Public Accounting Firm F-2 Balance Sheet F-3 Notes to Financial Statement F-4 F-1 Report of Independent Registered Public Accounting Firm To the Shareholders and Board of Directors of Helix Acquisition Corp. II Opinion on the Financial Statement We have audited the accompanying balance sheet

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): February 13, 2024 HELIX ACQUISITION CORP. II (Exact name of registrant as specified in its charter) Cayman Islands 001-41955 N/A (State or other jurisdiction of (Commission File Numbe

Indemnification Agreement, dated February 8, 2024, between Helix Acquisition Corp. II and Bihua Chen.

EX-99.6 3 ea0200275ex99-6helix2.htm INDEMNIFICATION AGREEMENT, DATED FEBRUARY 8, 2024, BETWEEN HELIX ACQUISITION CORP. II AND BIHUA CHEN Exhibit 6 INDEMNITY AGREEMENT THIS INDEMNITY AGREEMENT (this “Agreement”) is made as of February 8, 2024, by and between HELIX ACQUISITION CORP. II, a Cayman Islands exempted company (the “Company”), and Bihua Chen (“Indemnitee”). RECITALS WHEREAS, highly compete

HLXB / Helix Acquisition Corp. II / Helix Holdings II LLC - SCHEDULE 13D Activist Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13D   Under the Securities Exchange Act of 1934   (Amendment No. )* Helix Acquisition Corp. II (Name of Issuer)   Class A ordinary shares, $0.0001 par value per share (Title of Class of Securities)   G4444H 101 (CUSIP Number)   Helix Holdings II LLC C/O Cormorant Asset Management, LP 200 Clarendon Street, 52nd Floor B

HLXB / Helix Acquisition Corp. II / INTEGRATED CORE STRATEGIES (US) LLC Passive Investment

SC 13G 1 HLXBSC13G.htm UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 HELIX ACQUISITION CORP. II (Name of Issuer) CLASS A ORDINARY SHARES, PAR VALUE $0.0001 PER SHARE (Title of Class of Securities) G4444H101 (CUSIP Number) FEBRUARY 9, 2024 (Date of event which requires filing of this statement) Check the appropriate bo

Registration Rights Agreement, dated February 8, 2024, among Helix Acquisition Corp. II, Helix Holdings II LLC, and the other shareholders party thereto (incorporated by reference to Exhibit 10.3 to Helix’s Current Report on Form 8-K (File No. 001-41955), filed with the SEC on February 14, 2024).

Exhibit 10.3 REGISTRATION RIGHTS AGREEMENT THIS REGISTRATION RIGHTS AGREEMENT (this “Agreement”), dated as of February 8, 2024, is made and entered into by and among Helix Acquisition Corp. II, a Cayman Islands exempted company (the “Company”), Helix Holdings II LLC, a Cayman Islands limited liability company (the “Sponsor”) and each of the undersigned parties listed on the signature page hereto u

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Entry into a Material Definitive Agreement, Unregistered Sales of Equity Securities, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 Date of Report (Date of earliest event reported): February 8, 2024 HELIX ACQUISITION CORP. II (Exact name of registrant as specified in its charter) Cayman Islands 001-41955 N/A (State or other jurisdiction (Commission File Number) (

Helix Acquisition Corp. II Amended and Restated Memorandum and Articles of Association (incorporated by reference to Exhibit 3.1 to Helix’s Current Report on Form 8-K (File No. 001-41955), filed with the SEC on February 14, 2024).

Exhibit 3.1 THE COMPANIES ACT (AS REVISED) OF THE CAYMAN ISLANDS COMPANY LIMITED BY SHARES AMENDED AND RESTATED MEMORANDUM AND ARTICLES OF ASSOCIATION OF HELIX ACQUISITION CORP. II (ADOPTED BY SPECIAL RESOLUTION DATED 8 FEBRUARY 2024 AND EFFECTIVE ON 8 FEBRUARY 2024) THE COMPANIES ACT (AS REVISED) OF THE CAYMAN ISLANDS COMPANY LIMITED BY SHARES AMENDED AND RESTATED MEMORANDUM OF ASSOCIATION OF HEL

Helix Acquisition Corp. II Announces Closing of $184 Million Initial Public Offering, Including the Full Exercise of the Underwriter’s Option to Purchase Additional Shares

Exhibit 99.2 Helix Acquisition Corp. II Announces Closing of $184 Million Initial Public Offering, Including the Full Exercise of the Underwriter’s Option to Purchase Additional Shares Boston, MA – Feb. 14, 2024 – Helix Acquisition Corp. II (Nasdaq: HLXB) (the “Company”) announced today that on February 13, 2024 it closed the initial public offering of 18,400,000 Class A ordinary shares which incl

Investment Management Trust Agreement, dated February 8, 2024, between Helix Acquisition Corp. II and Continental Stock Transfer and Trust Company (incorporated by reference to Exhibit 10.2 to Helix’s Current Report on Form 8-K (File No. 001-41955), filed with the SEC on February 14, 2024).

Exhibit 10.2 INVESTMENT MANAGEMENT TRUST AGREEMENT This Investment Management Trust Agreement (this “Agreement”) is made effective as of February 8, 2024 by and between Helix Acquisition Corp. II, a Cayman Islands exempted company (the “Company”), and Continental Stock Transfer & Trust Company, a New York corporation (the “Trustee”). WHEREAS, the Company’s registration statement on Form S-1, File

Private Placement Class A Ordinary Shares Purchase Agreement, dated February 8, 2024, by and between Helix Acquisition Corp. II and Helix Holdings II LLC (incorporated by reference to Exhibit 10.4 to Helix’s Current Report on Form 8-K (File No. 001-41955), filed with the SEC on February 14, 2024).

Exhibit 10.4 PRIVATE PLACEMENT SHARES PURCHASE AGREEMENT THIS PRIVATE PLACEMENT SHARES PURCHASE AGREEMENT, dated as of February 8, 2024 (as it may from time to time be amended, this “Agreement”), is entered into by and between Helix Acquisition Corp. II, a Cayman Islands exempted company (the “Company”), and Helix Holdings II LLC, a Cayman Islands limited liability company (the “Purchaser”). WHERE

Administrative Services and Indemnification Agreement, dated February 8, 2024, by and between Helix Acquisition Corp. II and Helix Holdings II LLC (incorporated by reference to Exhibit 10.5 to Helix’s Current Report on Form 8-K (File No. 001-41955), filed with the SEC on February 14, 2024).

Exhibit 10.5 HELIX ACQUISITION CORP. II c/o Cormorant Asset Management, LP 200 Clarendon Street, 52nd Floor Boston, MA 02116 February 8th, 2024 Helix Holdings II LLC c/o Cormorant Asset Management, LP 200 Clarendon Street, 52nd Floor Boston, MA 02116 Re: Administrative Services and Indemnification Agreement Ladies and Gentlemen: This letter agreement (this “Agreement”) by and between Helix Acquisi

Letter Agreement, dated February 8, 2024, among Helix Acquisition Corp. II, Helix Holdings LLC, and each of the officers, directors and advisor to Helix Acquisition Corp. II (incorporated by reference to Exhibit 10.1 to Helix’s Current Report on Form 8-K (File No. 001-41955), filed with the SEC on February 14, 2024).

Exhibit 10.1 February 8, 2024 Helix Acquisition Corp. II c/o Cormorant Asset Management, LP 200 Clarendon Street, 52nd Floor Boston, MA 02116 Re: Initial Public Offering Ladies and Gentlemen: This letter (this “Letter Agreement”) is being delivered to you in accordance with the Underwriting Agreement (the “Underwriting Agreement”) entered into by and among Helix Acquisition Corp. II, a Cayman Isla

Helix Acquisition Corp. II Announces Pricing of Upsized $160 Million Initial Public Offering

Exhibit 99.1 Helix Acquisition Corp. II Announces Pricing of Upsized $160 Million Initial Public Offering Boston, Massachusetts—February 9, 2024—Helix Acquisition Corp. II (the “Company”) announced today that it priced its upsized initial public offering of 16,000,000 Class A ordinary shares at $10.00 per share. The shares will be listed on The Nasdaq Global Market and trade under the ticker symbo

Underwriting Agreement, dated February 8, 2024, between the Company and Leerink Partners LLC.

Exhibit 1.1 EXECUTION VERSION 16,000,000 Class A Ordinary Shares Helix Acquisition Corp. II UNDERWRITING AGREEMENT February 8, 2024 Leerink Partners LLC 1301 Avenue of the Americas, 12th Floor New York, New York 10019 Ladies and Gentlemen: Helix Acquisition Corp. II, a Cayman Islands exempted company (the “Company”), proposes to sell to Leerink Partners LLC (the “Underwriter”), 16,000,000 Class A

$160,000,000 HELIX ACQUISITION CORP. II 16,000,000 Class A ordinary shares

Filed Pursuant to Rule 424(b)(4) Registration Nos. 333-276591 and 333-276958 PROSPECTUS $160,000,000 HELIX ACQUISITION CORP. II 16,000,000 Class A ordinary shares Helix Acquisition Corp. II is a blank check company incorporated as a Cayman Islands exempted company for the purpose of effecting a merger, share exchange, asset acquisition, share purchase, reorganization or similar business combinatio

As filed with the Securities and Exchange Commission on February 8, 2024.

As filed with the Securities and Exchange Commission on February 8, 2024. Registration No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 HELIX ACQUISITION CORP. II (Exact name of registrant as specified in its charter) Cayman Islands 6770 N/A (State or other jurisdiction of incorporation or organization

Filing Fee Table.

Exhibit 107 Calculation of Filing Fee Tables Form S-1 (Form Type) Helix Acquisition Corp.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-A FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES PURSUANT TO SECTION 12(b) OR 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 Helix Acquisition Corp. II (Exact name of reg

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-A FOR REGISTRATION OF CERTAIN CLASSES OF SECURITIES PURSUANT TO SECTION 12(b) OR 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 Helix Acquisition Corp. II (Exact name of registrant as specified in its charter) Cayman Islands N/A (State of incorporation or organization) (I.R.S. Employer Identification No.) Cormorant Asset

[signature page follows]

February 7, 2024 VIA EDGAR Securities and Exchange Commission Division of Corporation Finance Office of Real Estate & Construction 100 F Street, N.

Helix Acquisition Corp. II c/o Cormorant Asset Management, LP 200 Clarendon Street, 52nd Floor Boston, MA 02116

Helix Acquisition Corp. II c/o Cormorant Asset Management, LP 200 Clarendon Street, 52nd Floor Boston, MA 02116 February 7, 2024 VIA EDGAR Division of Corporation Finance United States Securities and Exchange Commission 100 F Street, NE Washington, D.C. 20549 Attn: Paul Cline Isaac Esquivel Ronald E. Alper Pam Howell Re: Helix Acquisition Corp. II Registration Statement on Form S-1 Filed January 1

As filed with the U.S. Securities and Exchange Commission on February 6, 2024.

As filed with the U.S. Securities and Exchange Commission on February 6, 2024. Registration No. 333-276591 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 AMENDMENT NO. 2 TO FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 HELIX ACQUISITION CORP. II (Exact name of registrant as specified in its charter) Cayman Islands 6770 N/A (State or other jurisdiction of

* * *

February 6, 2024 VIA EDGAR United States Securities and Exchange Commission Division of Corporation Finance, Office of Real Estate & Construction 100 F Street, NE Washington, D.

Form of Registration Rights Agreement among the Registrant, Helix Holdings II LLC and the Holders signatory thereto.

Exhibit 10.3 REGISTRATION RIGHTS AGREEMENT THIS REGISTRATION RIGHTS AGREEMENT (this “Agreement”), dated as of , 2024, is made and entered into by and among Helix Acquisition Corp. II, a Cayman Islands exempted company (the “Company”), Helix Holdings II LLC, a Cayman Islands limited liability company (the “Sponsor”) and each of the undersigned parties listed on the signature page hereto under “Hold

Form of Underwriting Agreement.

Exhibit 1.1 15,000,000 Class A Ordinary Shares Helix Acquisition Corp. II UNDERWRITING AGREEMENT [●], 2024 Leerink Partners LLC 1301 Avenue of the Americas, 12th Floor New York, New York 10019 Ladies and Gentlemen: Helix Acquisition Corp. II, a Cayman Islands exempted company (the “Company”), proposes to sell to Leerink Partners LLC (the “Underwriter”), 15,000,000 Class A ordinary shares, par valu

Form of Private Placement Shares Purchase Agreement among the Registrant and Helix Holdings II LLC.

Exhibit 10.4 PRIVATE PLACEMENT SHARES PURCHASE AGREEMENT THIS PRIVATE PLACEMENT SHARES PURCHASE AGREEMENT, dated as of , 2024 (as it may from time to time be amended, this “Agreement”), is entered into by and between Helix Acquisition Corp. II, a Cayman Islands exempted company (the “Company”), and Helix Holdings II LLC, a Cayman Islands limited liability company (the “Purchaser”). WHEREAS, the Co

* * *

February 2, 2024 VIA EDGAR United States Securities and Exchange Commission Division of Corporation Finance, Office of Real Estate & Construction 100 F Street, NE Washington, D.

Form of Investment Management Trust Agreement between Continental Stock Transfer & Trust Company and the Registrant.

Exhibit 10.2 INVESTMENT MANAGEMENT TRUST AGREEMENT This Investment Management Trust Agreement (this “Agreement”) is made effective as of , 2024 by and between Helix Acquisition Corp. II, a Cayman Islands exempted company (the “Company”), and Continental Stock Transfer & Trust Company, a New York corporation (the “Trustee”). WHEREAS, the Company’s registration statement on Form S-1, File No. 333- 2

Filing Fee Table.

Exhibit 107 Calculation of Filing Fee Table Form S-1 (Form Type) Helix Acquisition Corp.

Form of Letter Agreement among the Registrant, Helix Holdings II LLC and each of the officers and directors of the Registrant.

Exhibit 10.1 [ ], 2024 Helix Acquisition Corp. II c/o Cormorant Asset Management, LP 200 Clarendon Street, 52nd Floor Boston, MA 02116 Re: Initial Public Offering Ladies and Gentlemen: This letter (this “Letter Agreement”) is being delivered to you in accordance with the Underwriting Agreement (the “Underwriting Agreement”) entered into by and among Helix Acquisition Corp. II, a Cayman Islands exe

As filed with the U.S. Securities and Exchange Commission on February 2, 2024.

As filed with the U.S. Securities and Exchange Commission on February 2, 2024. Registration No. 333-276591 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 AMENDMENT NO. 1 TO FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 HELIX ACQUISITION CORP. II (Exact name of registrant as specified in its charter) Cayman Islands 6770 N/A (State or other jurisdiction of

Form of Private Placement Shares Purchase Agreement among the Registrant and Helix Holdings II LLC.

Exhibit 10.4 PRIVATE PLACEMENT SHARES PURCHASE AGREEMENT THIS PRIVATE PLACEMENT SHARES PURCHASE AGREEMENT, dated as of , 2024 (as it may from time to time be amended, this “Agreement”), is entered into by and between Helix Acquisition Corp. II, a Cayman Islands exempted company (the “Company”), and Helix Holdings II LLC, a Cayman Islands limited liability company (the “Purchaser”). WHEREAS, the Co

Consent of Mark McKenna.

Exhibit 99.1 Consent to be Named as a Director Nominee In connection with the filing by Helix Acquisition Corp. II of the Registration Statement on Form S-1 with the Securities and Exchange Commission under the Securities Act of 1933, as amended (the “Securities Act”), I hereby consent, pursuant to Rule 438 of the Securities Act, to being named as a nominee to the board of directors of Helix Acqui

* * *

January 18, 2024 VIA EDGAR United States Securities and Exchange Commission Division of Corporation Finance, Office of Real Estate & Construction 100 F Street, NE Washington, D.

Memorandum and Articles of Association.

Exhibit 3.1 THE COMPANIES ACT (AS REVISED) OF THE CAYMAN ISLANDS COMPANY LIMITED BY SHARES MEMORANDUM AND ARTICLES OF ASSOCIATION OF HELIX ACQUISITION CORP. II THE COMPANIES ACT (AS REVISED) OF THE CAYMAN ISLANDS COMPANY LIMITED BY SHARES MEMORANDUM OF ASSOCIATION OF HELIX ACQUISITION CORP. II 1. The name of the Company is Helix Acquisition Corp. II 2. The Registered Office of the Company shall be

Form of Administrative Services and Indemnification Agreement between the Registrant and Helix Holdings II LLC.

Exhibit 10.8 HELIX ACQUISITION CORP. II c/o Cormorant Asset Management, LP 200 Clarendon Street, 52nd Floor Boston, MA 02116 [ ], 2024 Helix Holdings II LLC c/o Cormorant Asset Management, LP 200 Clarendon Street, 52nd Floor Boston, MA 02116 Re: Administrative Services and Indemnification Agreement Ladies and Gentlemen: This letter agreement (this “Agreement”) by and between Helix Acquisition Corp

Form of Investment Management Trust Agreement between Continental Stock Transfer & Trust Company and the Registrant.

Exhibit 10.2 INVESTMENT MANAGEMENT TRUST AGREEMENT This Investment Management Trust Agreement (this “Agreement”) is made effective as of , 2024 by and between Helix Acquisition Corp. II, a Cayman Islands exempted company (the “Company”), and Continental Stock Transfer & Trust Company, a New York corporation (the “Trustee”). WHEREAS, the Company’s registration statement on Form S-1, File No. 333-[●

As filed with the U.S. Securities and Exchange Commission on January 18, 2024.

As filed with the U.S. Securities and Exchange Commission on January 18, 2024. Registration No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 HELIX ACQUISITION CORP. II (Exact name of registrant as specified in its charter) Cayman Islands 6770 N/A (State or other jurisdiction of incorporation or organiz

Form of Code of Business Conduct and Ethics.

Exhibit 14.1 HELIX ACQUISITION CORP. II FORM OF CODE OF BUSINESS CONDUCT AND ETHICS Effective [ ], 2024 I. Introduction The Board of Directors (the “Board”) of Helix Acquisition Corp. II has adopted this code of business conduct and ethics (this “Code”), as amended from time to time by the Board and which is applicable to all of the Company’s directors, officers and employees (to the extent that e

Securities Subscription Agreement between Helix Holdings II LLC and the Registrant.

Exhibit 10.7 HELIX ACQUISITION CORP. II c/o Cormorant Asset Management, LP 200 Clarendon Street Boston, MA 02116 United States June 19, 2021 Helix Holdings II LLC c/o Cormorant Asset Management, LP 200 Clarendon Street Boston, MA 02116 United States RE: Securities Subscription Agreement Ladies and Gentlemen: Helix Acquisition Corp. II, a Cayman Islands exempted company (the “Company,” “we” or “us”

Form of Indemnity Agreement.

Exhibit 10.5 INDEMNITY AGREEMENT THIS INDEMNITY AGREEMENT (this “Agreement”) is made as of , 2024, by and between HELIX ACQUISITION CORP. II, a Cayman Islands exempted company (the “Company”), and (“Indemnitee”). RECITALS WHEREAS, highly competent persons have become more reluctant to serve publicly-held corporations as directors, officers or in other capacities unless they are provided with adequ

Specimen Ordinary Share Certificate.

Exhibit 4.1 SHARES NUMBER C- SEE REVERESE FOR CERTAIN DEFINITIONS CUSIP [●] HELIX ACQUISITION CORP. II CLASS A ORDINARY SHARES THIS CERTIFIES THAT is the owner of Class A ordinary shares, par value $0.0001 per share (each, a “Class A Ordinary Share”), of Helix Acquisition Corp. II, a Cayman Islands exempted company (the “Company”), transferable on the books of the Company in person or by duly auth

Filing Fee Table.

Exhibit 107 Calculation of Filing Fee Table Form S-1 (Form Type) Helix Acquisition Corp.

Form of Amended and Restated Memorandum and Articles of Association.

Exhibit 3.2 THE COMPANIES ACT (AS REVISED) OF THE CAYMAN ISLANDS COMPANY LIMITED BY SHARES AMENDED AND RESTATED MEMORANDUM AND ARTICLES OF ASSOCIATION OF HELIX ACQUISITION CORP. II (ADOPTED BY SPECIAL RESOLUTION DATED [ ] 2024 AND EFFECTIVE ON [ ] 2024) THE COMPANIES ACT (AS REVISED) OF THE CAYMAN ISLANDS COMPANY LIMITED BY SHARES AMENDED AND RESTATED MEMORANDUM OF ASSOCIATION OF HELIX ACQUISITION

Promissory Note issued to Helix Holdings II LLC.

Exhibit 10.6 THIS PROMISSORY NOTE (“NOTE”) HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”). THIS NOTE HAS BEEN ACQUIRED FOR INVESTMENT ONLY AND MAY NOT BE SOLD, TRANSFERRED OR ASSIGNED IN THE ABSENCE OF REGISTRATION OF THE RESALE THEREOF UNDER THE SECURITIES ACT OR AN OPINION OF COUNSEL REASONABLY SATISFACTORY IN FORM, SCOPE AND SUBSTANCE TO THE COMPANY

Form of Letter Agreement among the Registrant, Helix Holdings II LLC and each of the officers and directors of the Registrant.

Exhibit 10.1 [ ], 2024 Helix Acquisition Corp. II c/o Cormorant Asset Management, LP 200 Clarendon Street, 52nd Floor Boston, MA 02116 Re: Initial Public Offering Ladies and Gentlemen: This letter (this “Letter Agreement”) is being delivered to you in accordance with the Underwriting Agreement (the “Underwriting Agreement”) entered into by and among Helix Acquisition Corp. II, a Cayman Islands exe

Form of Registration Rights Agreement among the Registrant, Helix Holdings II LLC and the Holders signatory thereto.

Exhibit 10.3 REGISTRATION RIGHTS AGREEMENT THIS REGISTRATION RIGHTS AGREEMENT (this “Agreement”), dated as of , 2024, is made and entered into by and among Helix Acquisition Corp. II, a Cayman Islands exempted company (the “Company”), Helix Holdings II LLC, a Cayman Islands limited liability company (the “Sponsor”) and each of the undersigned parties listed on the signature page hereto under “Hold

Consent of John Schmid.

Exhibit 99.2 Consent to be Named as a Director Nominee In connection with the filing by Helix Acquisition Corp. II of the Registration Statement on Form S-1 with the Securities and Exchange Commission under the Securities Act of 1933, as amended (the “Securities Act”), I hereby consent, pursuant to Rule 438 of the Securities Act, to being named as a nominee to the board of directors of Helix Acqui

As confidentially submitted to the Securities and Exchange Commission on December 20, 2023. This draft registration statement has not been publicly filed with the Securities and Exchange Commission, and all information herein is strictly confidential

As confidentially submitted to the Securities and Exchange Commission on December 20, 2023.