Merger cashes out Generation Bio (GBIO) shares and cancels stock options

Rhea-AI Filing Summary

Generation Bio Co. has been acquired by XOMA Royalty Corporation under a Merger Agreement dated December 15, 2025. Common shareholders who tendered their shares received $4.2913 in cash per share plus one non-tradeable contingent value right (CVR) per share, with an estimated maximum contingent payment of $25.01 per CVR. At the February 9, 2026 effective time, director Donald William Nicholson’s 21,357 common shares and multiple stock option grants were cancelled or cashed out as specified in the merger terms, leaving no reported remaining holdings.

Insights

Equity compensation and M&A analyst

Merger cashes out Generation Bio equity and cancels options per set terms.

The transaction converts Generation Bio’s public equity into cash plus a contingent value right. Stockholders receive $4.2913 in cash per share and one CVR, which has an estimated maximum contingent payment of $25.01 per CVR under a separate rights agreement.

For equity awards, in-the-money stock options became fully vested and were cancelled in exchange for cash equal to the spread between the cash amount and the exercise price, multiplied by option shares. Out-of-the-money options were cancelled for no consideration, consistent with their lack of intrinsic value at the deal price.

For director Donald William Nicholson, the Form 4 shows 21,357 common shares and several stock option grants reduced to zero following the merger effective on February 9, 2026. Subsequent company disclosures may provide aggregate cash paid for equity awards and any realized value from the CVRs.

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).

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^*

Nicholson Donald William

(Last) (First) (Middle)

C/O GENERATION BIO CO.

301 BINNEY ST, SUITE 401

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Generation Bio Co. [ GBIO ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
02/09/2026

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	02/09/2026		U(1)(2)		21,357	D	(1)(2)	0	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
Stock Option (right to buy)	$3.874	02/09/2026		D			3,000	(3)	(3)	Common Stock	3,000	(3)	0	D
Stock Option (right to buy)	$190	02/09/2026		D			5,200	(4)	(4)	Common Stock	5,200	(4)	0	D
Stock Option (right to buy)	$265.9	02/09/2026		D			1,500	(4)	(4)	Common Stock	1,500	(4)	0	D
Stock Option (right to buy)	$61.9	02/09/2026		D			1,920	(4)	(4)	Common Stock	1,920	(4)	0	D
Stock Option (right to buy)	$48.3	02/09/2026		D			2,500	(4)	(4)	Common Stock	2,500	(4)	0	D
Stock Option (right to buy)	$33.2	02/09/2026		D			6,000	(4)	(4)	Common Stock	6,000	(4)	0	D

Explanation of Responses:

1. Pursuant to the terms of that certain Agreement and Plan of Merger (the "Merger Agreement"), by and among Generation Bio. Co. (the "Issuer"), XOMA Royalty Corporation ("Parent") and Parent's wholly-owned subsidiary, XRA 7 Corp. ("Merger Sub"), dated as of December 15, 2025, the shares (the "Shares") of common stock, par value $0.0001 per share, of the Issuer (the "Common Stock") that were tendered to Merger Sub prior to the expiration time of the offer were exchanged for (i) a purchase price of $4.2913 per Share to the stockholders in cash, without interest and less any applicable tax withholding (the "Cash Amount"), plus (ii) one non-tradeable contingent value right per Share (the "CVR"),

2. (continued from footnote 1) which represents the right to receive certain contingent payments in cash in accordance with the terms and subject to the conditions of a contingent value rights agreement entered into by Parent and the rights agent, with an estimated maximum contingent consideration amount of $25.01 per CVR (the Cash Amount plus one CVR, collectively, the "Offer Price"). After completion of the tender offer, pursuant to the terms of the Merger Agreement, Merger Sub merged with and into the Issuer, effective as of February 9, 2026 (the "Effective Time"), with the Issuer continuing as the surviving corporation and a wholly owned subsidiary of Parent.

3. Pursuant to the terms of the Merger Agreement, effective as of immediately prior to the Effective Time, each option to purchase shares of Common Stock ("Issuer Option") that was outstanding and unexercised as of immediately prior to the Effective Time and had an exercise price per Share that was less than the Cash Amount (each, an "In-The-Money Option"), became fully vested and was automatically cancelled and converted into the right to receive an amount in cash, without interest, equal to the product obtained by multiplying (x) the excess of the Cash Amount over the exercise price per share of Common Stock underlying such In-the-Money Option at the Effective Time by (y) the number of shares of Common Stock underlying such In-the-Money Option at the Effective Time.

4. Pursuant to the terms of the Merger Agreement, effective as of immediately prior to the Effective Time, each Issuer Option that was outstanding and unexercised as of immediately prior to the Effective Time and had an exercise price per Share that was equal to or greater than the Cash Amount was automatically cancelled for no consideration.

	/s/ Shawna-Gay White, Attorney-in-Fact	02/09/2026
	** Signature of Reporting Person	Date
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FAQ

What did Generation Bio (GBIO) shareholders receive in the XOMA Royalty merger?

Generation Bio shareholders received $4.2913 in cash per share plus one non‑tradeable contingent value right (CVR) per share. Each CVR can pay contingent cash amounts up to an estimated maximum of $25.01, depending on terms in a separate rights agreement.

How were Generation Bio (GBIO) stock options treated in the merger?

In‑the‑money Generation Bio stock options became fully vested, were cancelled, and converted into a cash payment equal to their intrinsic value. Options with an exercise price at or above the $4.2913 cash amount were automatically cancelled for no consideration immediately before the merger closing.

What happened to director Donald William Nicholson’s Generation Bio (GBIO) shares?

Director Donald William Nicholson reported disposition of 21,357 common shares in connection with the merger, leaving zero common shares beneficially owned afterward. Those shares were exchanged for the cash and CVR merger consideration under the agreed offer terms.

What happened to Donald William Nicholson’s Generation Bio stock options?

The Form 4 shows several stock option grants with share amounts such as 3,000 and 6,000 being disposed of with zero options remaining. These options were either cashed out as in‑the‑money awards or cancelled without payment, depending on their exercise prices versus the cash amount.

When did the Generation Bio (GBIO) merger with XOMA Royalty become effective?

The merger became effective on February 9, 2026, when XRA 7 Corp., a wholly owned subsidiary of XOMA Royalty, merged with and into Generation Bio. At that time, Generation Bio became a wholly owned subsidiary and its public equity was converted into the agreed consideration.

Is the contingent value right (CVR) from the Generation Bio merger tradeable?

The CVR issued in the Generation Bio transaction is described as non‑tradeable. Each CVR represents the right to receive potential future cash payments up to an estimated maximum of $25.01 per CVR, based on conditions detailed in a contingent value rights agreement.