Gossamer Bio (GOSS) reprices EVP Caryn Peterson’s stock options to $0.45

Rhea-AI Filing Summary

Gossamer Bio, Inc. executive Caryn Peterson, EVP of Regulatory Affairs, reported a one-time repricing of multiple stock option awards effective March 19, 2026. Previously granted options were surrendered back to the company and replacement options for the same share amounts were granted with a reduced exercise price of $0.45 per share. According to the disclosure, all other terms of these options, including vesting schedules and expiration dates under the 2019 Incentive Award Plan, remain unchanged and continue to depend on her ongoing service.

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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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^*

Peterson Caryn

(Last) (First) (Middle)

3115 MERRYFIELD ROW, SUITE 120

(Street)

SAN DIEGO CALIFORNIA 92121

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
Gossamer Bio, Inc. [ GOSS ]

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	EVP, Regulatory Affairs

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
03/19/2026

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

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

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

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

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)	$2.88	03/19/2026		D(1)			506,250	(2)	01/01/2036	Common Stock	506,250	(1)	0	D
Stock Option (Right to Buy)	$1.13	03/19/2026		D(1)			440,000	(2)	03/03/2035	Common Stock	440,000	(1)	0	D
Stock Option (Right to Buy)	$0.97	03/19/2026		D(1)			375,000	(2)	01/01/2034	Common Stock	375,000	(1)	0	D
Stock Option (Right to Buy)	$0.838	03/19/2026		D(1)			125,000	(2)	11/19/2033	Common Stock	125,000	(1)	0	D
Stock Option (Right to Buy)	$1.21	03/19/2026		D(1)			157,500	(2)	03/19/2033	Common Stock	157,500	(1)	0	D
Stock Option (Right to Buy)	$2.16	03/19/2026		D(1)			157,500	(2)	12/06/2032	Common Stock	157,500	(1)	0	D
Stock Option (Right to Buy)	$1.36	03/19/2026		D(1)			126,667	(2)	01/05/2032	Common Stock	126,667	(1)	0	D
Stock Option (Right to Buy)	$1.36	03/19/2026		D(1)			21,167	(2)	04/16/2031	Common Stock	21,167	(1)	0	D
Stock Option (Right to Buy)	$1.36	03/19/2026		D(1)			18,834	(2)	02/25/2031	Common Stock	18,834	(1)	0	D
Stock Option (Right to Buy)	$1.36	03/19/2026		D(1)			22,784	(2)	02/14/2030	Common Stock	22,784	(1)	0	D
Stock Option (Right to Buy)	$1.36	03/19/2026		D(1)			9,167	(2)	12/23/2029	Common Stock	9,167	(1)	0	D
Stock Option (Right to Buy)	$1.36	03/19/2026		D(1)			32,334	(2)	03/25/2029	Common Stock	32,334	(1)	0	D
Stock Option (Right to Buy)	$0.45	03/19/2026		A(1)		506,250		(2)	01/01/2036	Common Stock	506,250	(1)	506,250	D
Stock Option (Right to Buy)	$0.45	03/19/2026		A(1)		440,000		(2)	03/03/2035	Common Stock	440,000	(1)	440,000	D
Stock Option (Right to Buy)	$0.45	03/19/2026		A(1)		375,000		(2)	01/01/2034	Common Stock	375,000	(1)	375,000	D
Stock Option (Right to Buy)	$0.45	03/19/2026		A(1)		125,000		(2)	11/19/2033	Common Stock	125,000	(1)	125,000	D
Stock Option (Right to Buy)	$0.45	03/19/2026		A(1)		157,500		(2)	03/19/2023	Common Stock	157,500	(1)	157,500	D
Stock Option (Right to Buy)	$0.45	03/19/2026		A(1)		157,500		(2)	12/06/2032	Common Stock	157,500	(1)	157,500	D
Stock Option (Right to Buy)	$0.45	03/19/2026		A(1)		126,667		(2)	01/05/2032	Common Stock	126,667	(1)	126,667	D
Stock Option (Right to Buy)	$0.45	03/19/2026		A(1)		21,167		(2)	04/16/2031	Common Stock	21,167	(1)	21,167	D
Stock Option (Right to Buy)	$0.45	03/19/2026		A(1)		18,834		(2)	02/25/2031	Common Stock	18,834	(1)	18,834	D
Stock Option (Right to Buy)	$0.45	03/19/2026		A(1)		22,784		(2)	02/14/2030	Common Stock	22,784	(1)	22,784	D
Stock Option (Right to Buy)	$0.45	03/19/2026		A(1)		9,167		(2)	12/23/2029	Common Stock	9,167	(1)	9,167	D
Stock Option (Right to Buy)	$0.45	03/19/2026		A(1)		32,334		(2)	03/25/2029	Common Stock	32,334	(1)	32,334	D

Explanation of Responses:

1. Effective as of March 19, 2026 (the "Repricing Date"), the Issuer approved a one-time repricing of certain outstanding stock options (the "Repriced Options") granted under the Issuer's 2019 Incentive Award Plan (the "2019 Plan"), which reduced the per share exercise price of each Repriced Option to $0.45 (the "Option Repricing"). Except as modified by the Option Repricing, all other terms and conditions of the Repriced Options, including, without limitation, any provisions with respect to vesting and term of the Repriced Options, remain in full force and effect.

2. This stock option award was issued pursuant to the 2019 Plan and becomes exercisable in accordance with the vesting schedule specified in the award agreement and as previously reported on applicable Form 4, subject to the Reporting Person's continued service with the Issuer as of the applicable vesting date.

Remarks:

	/s/ Jeff Boerneke, Attorney-in-Fact	03/20/2026
	** 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.
* Form 4: SEC 1474 (03-26)

FAQ

What insider transaction did Gossamer Bio (GOSS) report for Caryn Peterson?

Gossamer Bio reported that EVP of Regulatory Affairs Caryn Peterson exchanged several existing stock options for new options. The new awards keep the same share counts and terms but reset the exercise price to $0.45 per share under the 2019 Incentive Award Plan.

Was this Gossamer Bio (GOSS) Form 4 a stock option repricing?

Yes. The filing describes a one-time repricing of certain outstanding stock options effective March 19, 2026. Existing options were returned to the issuer and replacement options were granted at an exercise price of $0.45, with all other vesting and term provisions remaining in effect.

How does the Gossamer Bio (GOSS) option repricing affect exercise price?

The option repricing reduces the per share exercise price of the affected stock options to $0.45. While the strike price changed, the filing states that all other terms, including vesting schedules and expiration dates, continue as previously established under the 2019 Incentive Award Plan.

Do Caryn Peterson’s Gossamer Bio (GOSS) repriced options change vesting terms?

No. The filing states that, apart from the new $0.45 exercise price, all other terms remain in full force. Vesting continues to follow the original award agreements and still depends on Peterson’s continued service with Gossamer Bio on each applicable vesting date.

Under which plan were Caryn Peterson’s Gossamer Bio (GOSS) options repriced?

The repriced stock options were granted under Gossamer Bio’s 2019 Incentive Award Plan. The Form 4 explains that the one-time repricing affects certain options issued pursuant to this plan, keeping existing vesting and term conditions while lowering the exercise price to $0.45 per share.

Did the Gossamer Bio (GOSS) Form 4 show net buying or selling of common stock?

No open-market buying or selling of common stock was reported. The Form 4 only shows derivative transactions: options disposed back to the issuer and replacement option grants, resulting in neutral net buy–sell share activity according to the transaction summary provided.