Michael R. Hayden - 30 Oct 2025 Form 4 Insider Report for 89bio, Inc. (ETNB)

Role: Director
Signature: /s/ Ryan A. Murr, as attorney-in-fact for Michael R. Hayden
Issuer symbol: ETNB
Transactions as of: 30 Oct 2025
Net transactions value: $0
Form type: 4
Filing time: 30 Oct 2025, 20:31:14 UTC
Previous filing: 17 Jul 2025
SEC: View on sec.gov

Quoteable Key Fact

"Michael R. Hayden filed Form 4 for 89bio, Inc. (ETNB) on 30 Oct 2025."

Quick Takeaways

This page summarizes Michael R. Hayden's Form 4 filing for 89bio, Inc. (ETNB).
13 reported transactions and 10 derivative rows are listed below.
Filing timestamp: 30 Oct 2025, 20:31.

What Changed

Previous filing in this sequence was filed on 17 Jul 2025.
Current net transaction value: $0.

Why This Matters

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Official SEC Source

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

See Original Filing

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Hayden Michael R	Director	C/O 89BIO, INC., 655 MONTGOMERY STREET, SUITE 1500, SAN FRANCISCO	/s/ Ryan A. Murr, as attorney-in-fact for Michael R. Hayden	30 Oct 2025	0001352908

Transactions Table

Type	Sym	Class	Transaction	Shares	Change %	Date	Ownership	Footnotes
transaction	ETNB	Common Stock	Disposition pursuant to a tender of shares in a change of control transaction	-80,904	-100%	30 Oct 2025	Direct	F1, F2
transaction	ETNB	Common Stock	Disposition pursuant to a tender of shares in a change of control transaction	-103,978	-100%	30 Oct 2025	See footnote	F1, F2, F3
transaction	ETNB	Common Stock	Disposition pursuant to a tender of shares in a change of control transaction	-61,538	-100%	30 Oct 2025	See footnote	F1, F2, F4

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	ETNB	Stock Option (Right to Buy)	Disposed to Issuer	$0	-27,647	-100%	$0.000000	30 Oct 2025	Common Stock	27,647	$1.93	Direct	F5, F6, F7
transaction	ETNB	Stock Option (Right to Buy)	Disposed to Issuer	$0	-2,933	-100%	$0.000000	30 Oct 2025	Common Stock	2,933	$1.93	Direct	F5, F6, F7
transaction	ETNB	Stock Option (Right to Buy)	Disposed to Issuer	$0	-22,730	-100%	$0.000000	30 Oct 2025	Common Stock	22,730	$3.11	Direct	F5, F6, F7
transaction	ETNB	Stock Option (Right to Buy)	Disposed to Issuer	$0	-7,000	-100%	$0.000000	30 Oct 2025	Common Stock	7,000	$21.40	Direct	F5, F6, F7
transaction	ETNB	Stock Option (Right to Buy)	Disposed to Issuer	$0	-7,000	-100%	$0.000000	30 Oct 2025	Common Stock	7,000	$24.29	Direct	F5, F6, F7
transaction	ETNB	Stock Option (Right to Buy)	Disposed to Issuer	$0	-12,500	-100%	$0.000000	30 Oct 2025	Common Stock	12,500	$24.16	Direct	F5, F6, F7
transaction	ETNB	Stock Option (Right to Buy)	Disposed to Issuer	$0	-25,000	-100%	$0.000000	30 Oct 2025	Common Stock	25,000	$2.64	Direct	F5, F6, F7
transaction	ETNB	Stock Option (Right to Buy)	Disposed to Issuer	$0	-27,400	-100%	$0.000000	30 Oct 2025	Common Stock	27,400	$14.70	Direct	F5, F6, F7
transaction	ETNB	Stock Option (Right to Buy)	Disposed to Issuer	$0	-45,150	-100%	$0.000000	30 Oct 2025	Common Stock	45,150	$9.98	Direct	F5, F6, F7
transaction	ETNB	Stock Option (Right to Buy)	Disposed to Issuer	$0	-56,400	-100%	$0.000000	30 Oct 2025	Common Stock	56,400	$9.60	Direct	F5, F6, F7

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Michael R. Hayden is no longer subject to Section 16 filing requirements. Form 4 or Form 5 obligations may continue.

Explanation of Responses:

Id	Content
F1	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, [continues to Footnote 2]
F2	[continues from Footnote 1] in cash, without interest less any required withholding taxes, upon the achievement of specified milestones on or prior to the applicable milestone outside dates, 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.
F3	These shares are held directly by Genworks 2 Consulting Inc., over which the Reporting Person's wife has sole voting and investment power.
F4	These shares are held directly by The Hayden Family Trust, over which the Reporting Person's wife has sole voting and investment power.
F5	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 6]
F6	[Continues from Footnote 5] 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 7]
F7	[Continues from Footnote 6] 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.