[Form 4] 89bio, Inc. Insider Trading Activity

Rhea-AI Filing Summary

89bio (ETNB) insider transaction tied to merger completion: A company officer reported activity on 10/30/2025 connected to the Roche acquisition terms. The filing shows 50,000 shares of common stock were acquired at $0 upon settlement of performance-based RSUs immediately prior to the effective time of the merger.

The officer then reported dispositions pursuant to the agreement: 351,684 shares of common stock (direct) and 13,694 shares (indirect, by spouse) were cancelled in exchange for the offer consideration of $14.50 per share in cash plus one CVR that may pay up to an additional $6.00 per share, subject to specified milestones. Multiple stock options were also cancelled/converted per the agreement mechanics, including options covering 4,063 and 3,312 shares at an exercise price of $3.11, and 50,000 shares at $32.50. Options with an exercise price of $20.50 or more were cancelled without payment.

Insights

M&A and equity compensation analyst

Merger closed; insider equity settled for $14.50 cash plus CVR.

The transactions reflect completion of the Roche acquisition of 89bio. The officer’s RSUs vested and settled immediately prior to the effective time, yielding 50,000 shares at $0, which were then exchanged for the merger consideration.

Common shares were cancelled in exchange for $14.50 per share plus one CVR that may pay up to $6.00 per share if milestones are achieved under the CVR Agreement. Listed options were treated per the agreement: in-the-money options received cash for intrinsic value plus a CVR; options with exercise prices at or above $20.50 were cancelled without payment.

Investor impact is administrative for this Form 4, documenting how the merger consideration applied to insider holdings. Actual CVR payments depend on milestone outcomes under the agreement.

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

OMB Number:			3235-0287
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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^*

Le-Nguyen Quoc

(Last) (First) (Middle)

C/O 89BIO, INC.

655 MONTGOMERY STREET, SUITE 1500

(Street)

SAN FRANCISCO CA 94111

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
89bio, Inc. [ ETNB ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
10/30/2025

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	10/30/2025		A		50,000(1)	A	$0	351,684	D
Common Stock	10/30/2025		U		351,684(2)(3)	D	(2)(3)	0	D
Common Stock	10/30/2025		U		13,694(2)(3)	D	(2)(3)	0	I	By Spouse

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
Stock Option (Right to Buy)	$3.11	10/30/2025		D			4,063	(4)(5)(6)	07/30/2029	Common Stock	4,063	$0	0	D
Stock Option (Right to Buy)	$3.11	10/30/2025		D			3,312	(4)(5)(6)	07/30/2029	Common Stock	3,312	$0	0	D
Stock Option (Right to Buy)	$32.5	10/30/2025		D			50,000	(4)(5)(6)	02/14/2030	Common Stock	50,000	$0	0	D
Stock Option (Right to Buy)	$23.01	10/30/2025		D			67,500	(4)(5)(6)	02/05/2031	Common Stock	67,500	$0	0	D
Stock Option (Right to Buy)	$4.44	10/30/2025		D			70,000	(4)(5)(6)	02/16/2032	Common Stock	70,000	$0	0	D
Stock Option (Right to Buy)	$14.7	10/30/2025		D			120,000	(4)(5)(6)	02/09/2033	Common Stock	120,000	$0	0	D
Stock Option (Right to Buy)	$9.98	10/30/2025		D			195,000	(4)(5)(6)	02/01/2034	Common Stock	195,000	$0	0	D
Stock Option (Right to Buy)	$9.6	10/30/2025		D			320,000	(4)(5)(6)	02/01/2035	Common Stock	320,000	$0	0	D
Stock Option (Right to Buy)	$10.58	10/30/2025		D			26,400	(4)(5)(6)	04/02/2034	Common Stock	26,400	$0	0	I	By Spouse
Stock Option (Right to Buy)	$9.6	10/30/2025		D			17,500	(4)(5)(6)	02/01/2035	Common Stock	17,500	$0	0	I	By Spouse

Explanation of Responses:

1. Represents settlement by the Issuer of performance-based restricted stock units granted to the Reporting Person under the Company's Amended and Restated 2019 Equity Incentive Plan on September 9, 2022 and February 1, 2024, which vested as of immediately prior to and conditioned upon the occurrence of the effective time of the Merger (as defined below), pursuant to the Merger Agreement (as defined below).

2. Disposed of pursuant to the Agreement and Plan of Merger (the "Merger Agreement"), dated as of September 17, 2025, by and among 89bio, Inc. (the "Issuer"), Roche Holdings, Inc. ("Parent") and Bluefin Merger Subsidiary, Inc., a wholly owned subsidiary of Parent ("Merger Sub"). On October 30, 2025, Parent and Merger Sub completed a tender offer pursuant to the terms of the Merger Agreement for all outstanding shares of common stock of the Issuer (each, a "Share") for an offer price of (i) $14.50 per Share in cash, without interest (the "Closing Amount") less any required withholding taxes, plus (ii) one non-tradeable contingent value right (each, a "CVR") representing the right to receive certain contingent payments of up to an aggregate amount of $6.00 per Share, in cash, without interest less any required withholding taxes, upon the achievement of specified milestones on or prior to the applicable milestone outside dates, [continues to Footnote 3]

3. [continues from Footnote 2] subject to and in accordance with the terms of the Contingent Value Rights Agreement (the "CVR Agreement") (the Closing Amount plus one CVR, collectively, the "Offer Price"). Merger Sub thereafter merged with and into the Issuer, with the Issuer continuing as the surviving corporation and a wholly owned subsidiary of Parent (the "Merger"). At the effective time of the Merger, each issued and outstanding Share (other than any Excluded Shares (as such term is defined in the Merger Agreement)) was cancelled in exchange for the right to receive the Offer Price. In addition, as of immediately prior to and conditioned upon the occurrence of the effective time of the Merger, pursuant to the Merger Agreement, each outstanding restricted stock unit or performance-based restricted stock unit became fully vested and was cancelled in exchange for the right to receive the Offer Price.

4. As of immediately prior to and conditioned upon the occurrence of the effective time of the Merger, pursuant to the Merger Agreement, each outstanding option to purchase Shares (each, an "Option") became fully vested and exercisable, and to the extent not exercised prior to the effective time of the Merger, was cancelled and converted into the right to receive (i) an amount in cash (without interest and subject to deduction for any required withholding taxes) equal to the product of (A) an amount equal to the excess of the Closing Amount over the exercise price per Share with respect to such Option and (B) the number of Shares subject to such Option plus (ii) one CVR with respect to each Share subject to such Option (the "Option Consideration"); provided, however, that if the exercise price per Share of any Option was equal to or greater than the Closing Amount, but less than $20.50 (any such option, an "Out of the Money Option"), [continues to Footnote 5]

5. [Continues from Footnote 4] such Out of the Money Option was not entitled to any payment of the Closing Amount in respect thereof and each Out of the Money Option was converted into the right to receive the CVR included in the Option Consideration with respect to each Share underlying such Out of the Money Option and became entitled to receive, at each time a milestone payment becomes due and payable under the terms of the CVR Agreement, an amount in cash equal to the product of (i) the number of Shares subject to such Out of the Money Option, and (ii) the amount, if any, by which (A) the Closing Amount plus the applicable milestone payment plus any other milestone payment that previously became due and payable under the terms of the CVR Agreement exceeds (B) the exercise price per Share with respect to such Out of the Money Option plus the amounts, [continues to Footnote 6]

6. [Continues from Footnote 5] if any, paid to such Option holder with respect to such CVR in respect of any milestone payments that previously became due and payable under the terms of the CVR Agreement; provided further, that any Option with an exercise price that was equal to or greater than $20.50, was cancelled immediately prior to the effective time of the Merger without the receipt of any payment of the Closing Amount or CVR in respect thereof.

Remarks:

Chief Technical Operations Officer

	/s/ Ryan A. Murr, as attorney-in-fact for Quoc Le-Nguyen	10/30/2025
	** 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).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What did 89bio (ETNB) disclose in this Form 4?

An officer reported settlement of 50,000 RSU shares at $0 and disposition of common shares for the merger consideration on 10/30/2025.

What was the cash offer price for ETNB shares in the merger?

Each share was exchanged for $14.50 in cash plus one CVR that may pay up to $6.00 per share, subject to milestones.

How many ETNB shares did the officer dispose of under the merger terms?

The filing lists 351,684 shares (direct) and 13,694 shares (indirect, by spouse) exchanged for the offer consideration.

How were the officer’s stock options treated?

Options were cancelled/converted per the agreement; in-the-money options received cash for intrinsic value plus a CVR. Options with exercise price ≥ $20.50 were cancelled without payment.

When did these ETNB transactions occur?

The reported transaction date is 10/30/2025.

Who is the reporting person’s relationship to 89bio (ETNB)?

The reporting person is an officer (title noted as Chief Technical Operations Officer in remarks).

What does the CVR mean for ETNB holders?

Each CVR may pay up to $6.00 per share if specified milestones are achieved under the CVR Agreement.