Insider Filing — 30,000 Helix shares converted; director resigns

Rhea-AI Filing Summary

Mark C. McKenna filed a Form 4 reporting ownership changes tied to the business combination and domestication of Helix Acquisition Corp. II into the issuer, which is identified here as BridgeBio Oncology Therapeutics, Inc. [BBOT]. On 08/11/2025 McKenna's 30,000 Helix shares were converted through a one-for-one exchange of Class B ordinary shares into Class A ordinary shares and then into the issuer's common stock, resulting in 30,000 common shares beneficially owned, held directly. The filing shows the conversion occurred at $0 consideration as part of the corporate reorganization. The filer also resigned as a director of Helix effective the same date immediately prior to the domestication.

Positive

• 30,000 shares remain beneficially owned directly by the reporting person after conversion.
• One-for-one conversion of Class B to Class A and then to common stock was completed as part of the domestication with $0 cash consideration, reflecting a structural reclassification rather than a sale.

Negative

• Resignation from director role effective 08/11/2025, immediately prior to the domestication.
• Class B derivative holdings were converted and show 0 derivative securities remaining following the transaction.

Insights

Financial Analyst

TL;DR: Routine conversion of pre-existing Class B shares to common stock; reporting person retains 30,000 shares, transaction tied to corporate reorganization.

The Form 4 documents a non-cash, structural change rather than an open-market purchase or sale. The one-for-one conversion of Class B to Class A and then to common stock leaves the reporting person with 30,000 directly held common shares following the closing events on 08/11/2025. Because the filing reflects conversion under a business combination and domestication, it represents corporate housekeeping of equity records rather than a liquidity event. The director resignation effective immediately prior to domestication is a governance change investors may note but the filing does not provide reasons or additional compensatory details.

Corporate Governance Expert

TL;DR: Governance and capitalization were adjusted via domestication; insider converted shares and resigned as director the same day.

The disclosure clarifies that Helix's Class B shares had no expiration date pre-conversion and converted one-for-one into Class A shares, and then into issuer common stock as part of the domestication process. The reporter's resignation as a director effective immediately prior to domestication is explicitly noted. This Form 4 is descriptive of structural corporate actions and resultant beneficial ownership; it contains no indication of sales, option exercises for cash, or additional change in voting arrangements beyond the conversions described.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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X

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

McKenna Mark C.

(Last) (First) (Middle)

C/O HELIX ACQUISITION CORP. II

200 CLARENDON STREET, 52ND FLOOR

(Street)

BOSTON MA 02116

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
BridgeBio Oncology Therapeutics, Inc. [ BBOT ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
	Officer (give title below)	X	Other (specify below)
			Former Director

3. Date of Earliest Transaction (Month/Day/Year)
08/11/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	08/11/2025		M(1)		30,000	A	(1)	30,000	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Class B ordinary shares	(1)	08/11/2025		M(1)			30,000	(1)	(1)	Class A ordinary shares	30,000	$0	0	D

Explanation of Responses:

1. In connection with and prior to the closing of the business combination between the Issuer (which was formerly known as Helix Acquisition Corp. II, "Helix") and TheRas, Inc., among other things, (i) each of Helix's Class B ordinary shares converted into one Helix Class A ordinary share, on a one-for-one basis, as described under the heading "Description of Securities" in Helix's Registration Statement on Form S-1 (File No. 333-276591), (ii) Helix migrated to and domesticated as a Delaware corporation in accordance with Section 388 of the Delaware General Corporation Law, as amended, and the Cayman Islands Companies Act (As Revised) (the "Domestication"), and (iii) as a result of the Domestication, each Class A ordinary share of Helix converted into one share of the Issuer's common stock, on a one-for-one basis. Prior to such conversion, the Helix Class B ordinary shares had no expiration date.

Remarks:

The Reporting person was a director of Helix prior to the Domestication and resigned from such role effective as of August 11, 2025, immediately prior to the Domestication.

	/s/ Mark C. McKenna	08/11/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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FAQ

What did Mark C. McKenna report on Form 4 for HLXB?

The Form 4 reports that on 08/11/2025 Mark C. McKenna had 30,000 shares converted into the issuer's common stock and beneficially owns 30,000 common shares directly.

Why did the share class change occur according to the filing?

The filing states the change resulted from the business combination closing and a domestication, which converted Helix Class B shares to Class A shares one-for-one and then into the issuer's common stock.

Did the reporting person sell any shares or receive cash in the transaction?

No. The Form 4 shows the conversion was non-cash with a reported conversion price of $0, indicating a structural conversion rather than a sale.

What director or governance changes are disclosed in the Form 4?

The filer explicitly states that the reporting person resigned as a director of Helix effective as of 08/11/2025, immediately prior to domestication.

How many derivative securities remained after the conversion?

The filing indicates 0 derivative securities were beneficially owned following the reported conversion of Class B ordinary shares.