Form 4: Frazier Life Sciences Surrenders HLVX Holdings in Sept 2025 Merger

Rhea-AI Filing Summary

Frazier Life Sciences entities and related individuals reported disposition of HilleVax, Inc. (HLVX) common stock in connection with a merger completed on September 17, 2025. At the effective time each outstanding share was converted into $1.95 in cash and one non-transferable contractual contingent value right (CVR). The filing shows Frazier Life Sciences X, L.P. disposed of 8,535,337 shares and Patrick J. Heron disposed of 17,199 shares, both at $1.95 per share, resulting in zero shares owned following the transaction. The filing explains RSUs vested and were canceled for equivalent cash and CVRs. Reporting relationships and ownership chains among Frazier entities and two individuals are disclosed.

Positive

• Clear disclosure of merger consideration: $1.95 cash plus one CVR per share
• Complete disposition resulting in 0 shares owned by reporting entities post-merger
• RSU treatment disclosed: full vesting and cancellation for cash and CVRs

Negative

• Large holders disposed of 8,535,337 shares (Frazier Life Sciences X, L.P.), eliminating equity stakes
• CVRs are non-transferable, limiting market liquidity for contingent payments

Insights

Corporate Governance Expert

TL;DR Major pre-closing equity holdings were fully disposed of through a merger that converted shares into cash and CVRs, eliminating direct share ownership.

The Form 4 documents a definitive exit of reported common stock holdings by Frazier Life Sciences X, L.P. and an individual reporting person as part of the Merger Agreement with XOMA Royalty Corporation. The transaction converted each share into $1.95 cash plus one non-transferable CVR, and resulted in 0 shares beneficially owned by the reporting entities post-closing. The filing also clarifies corporate ownership and voting chains and confirms accelerated vesting and cancellation of RSUs for cash and CVRs. For governance review, this is a routine disclosure of merger consideration and ownership change; no regulatory or compliance issues are asserted in the form.

M&A Specialist

TL;DR The Form 4 reflects consummation of a merger where shareholders received cash and CVRs, with large pre-merger stakes surrendered.

The disclosure ties the dispositions to the Agreement and Plan of Merger dated August 4, 2025, and the Effective Time on September 17, 2025. It specifies the per-share cash component ($1.95) and issuance of one CVR per share and documents full vesting and cancellation of outstanding RSUs in exchange for equivalent cash and CVRs. The clear chain of indirect ownership through Frazier entities and the identification of individuals with shared voting and investment power provide necessary transparency for post-transaction ownership and control analysis. Materiality is transactional rather than operational.

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

OMB APPROVAL

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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).

1. Name and Address of Reporting Person^*

Frazier Life Sciences X, L.P.

(Last) (First) (Middle)

FRAZIER LIFE SCIENCES MANAGEMENT, L.P.

1001 PAGE MILL RD, BUILDING 4, SUITE B

(Street)

PALO ALTO CA 94304

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
HilleVax, Inc. [ HLVX ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
09/17/2025

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

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

	Form filed by One Reporting Person
X	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	09/17/2025		U		8,535,337	D	$1.95(1)	0	I	By Frazier Life Sciences X, L.P.(2)
Common Stock	09/17/2025		U		17,199	D	$1.95(3)	0	I	By Patrick J. Heron

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

1. Name and Address of Reporting Person^*

Frazier Life Sciences X, L.P.

(Last) (First) (Middle)

FRAZIER LIFE SCIENCES MANAGEMENT, L.P.

1001 PAGE MILL RD, BUILDING 4, SUITE B

(Street)

PALO ALTO CA 94304

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

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

1. Name and Address of Reporting Person^*

FHMLS X, L.P.

(Last) (First) (Middle)

FRAZIER LIFE SCIENCES MANAGEMENT, L.P.

1001 PAGE MILL RD, BUILDING 4, SUITE B

(Street)

PALO ALTO CA 94304

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

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

1. Name and Address of Reporting Person^*

FHMLS X, L.L.C.

(Last) (First) (Middle)

FRAZIER LIFE SCIENCES MANAGEMENT, L.P.

1001 PAGE MILL RD, BUILDING 4, SUITE B

(Street)

PALO ALTO CA 94304

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

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

1. Name and Address of Reporting Person^*

Topper James N

(Last) (First) (Middle)

FRAZIER LIFE SCIENCES MANAGEMENT, L.P.

1001 PAGE MILL RD, BUILDING 4, SUITE B

(Street)

PALO ALTO CA 94304

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

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

1. Name and Address of Reporting Person^*

Heron Patrick J

(Last) (First) (Middle)

FRAZIER LIFE SCIENCES MANAGEMENT, L.P.

1001 PAGE MILL RD, BUILDING 4, SUITE B

(Street)

PALO ALTO CA 94304

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

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

Explanation of Responses:

1. Reflects disposition of the Issuer's equity securities upon the consummation of the transactions contemplated by the Agreement and Plan of Merger (the "Merger Agreement"), dated as of August 4, 2025, by and among Issuer, XOMA Royalty Corporation ("Parent") and XRA 4 Corp., a wholly owned subsidiary of Parent ("Merger Sub"), including the consummation of the merger (the "Merger") between Issuer and Merger Sub on September 17, 2025. Pursuant to the Merger Agreement, as of the effective time of the Merger (the "Effective Time"), each share of the Issuer's Common Stock, par value $0.0001 per share ("Shares"), issued and outstanding immediately prior to the Effective Time was converted automatically into the right to receive (i) $1.95 in cash, without interest plus (ii) one non-transferable contractual contingent value right per Share.

2. The shares are held directly by Frazier Life Sciences X, L.P. FHMLS X,, L.P. is the general partner of Frazier Life Sciences X, L.P. and FHMLS X, L.L.C. is the general partner of FHMLS X, L.P. James N. Topper and Patrick J. Heron are the sole managing members of FHMLS X, L.L.C. and share voting and investment power over the shares held by Frazier Life Sciences X, L.P. Dr. Topper and Mr. Heron disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.

3. Pursuant to the terms of the Merger Agreement, immediately prior to the Effective Time, each outstanding restricted stock unit ("RSU") immediately vested in full and was canceled in exchange for the right receive (a) an amount in cash, without interest, equal to the product obtained by multiplying (x) the $1.95 by (y) the number of shares underlying such RSU at the Effective Time and (b) one CVR for each share underlying such RSU.

	/s/ Steve R. Bailey, CFO of FHMLS X, L.L.C., GP of FHMLS X, L.P., GP of Frazier Life Sciences X, L.P.	09/17/2025
	/s/ Steve R. Bailey, CFO of FHMLS X, L.L.C., GP of FHMLS X, L.P.	09/17/2025
	/s/ Steve R. Bailey, CFO of FHMLS X, L.L.C.	09/17/2025
	/s/ Steve R. Bailey, Attorney-in-Fact For Patrick J. Heron	09/17/2025
	/s/ Steve R. Bailey, Attorney-in-Fact For James N. Topper	09/17/2025
	** Signature of Reporting Person	Date
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FAQ

What did HLVX shareholders receive in the merger announced on September 17, 2025?

Each outstanding HLVX share was converted into $1.95 in cash and one non-transferable contractual contingent value right (CVR).

How many HLVX shares did Frazier Life Sciences X, L.P. dispose of?

Frazier Life Sciences X, L.P. disposed of 8,535,337 shares at $1.95 per share and held 0 shares after the transaction.

Did any restricted stock units (RSUs) get affected by the merger?

Yes. Each outstanding RSU vested in full immediately prior to the Effective Time and was canceled in exchange for cash equal to $1.95 per underlying share and one CVR per underlying share.

Who are the individuals with reported voting and investment power over the disposed shares?

James N. Topper and Patrick J. Heron are identified as sole managing members of FHMLS X, L.L.C. and share voting and investment power over the shares held by Frazier Life Sciences X, L.P.

What is the effective date of the merger that triggered these Form 4 dispositions?

The merger closed and became effective on September 17, 2025.