Gossamer Bio (GOSS) reprices Chief Medical Officer stock options

Rhea-AI Filing Summary

Gossamer Bio, Inc. reported that Chief Medical Officer Richard Aranda had a one-time repricing of certain outstanding stock options effective March 19, 2026. A series of existing options were surrendered back to the company and replaced with new options covering the same numbers of shares, but with a reduced exercise price of $0.45 per share.

According to the disclosure, all other terms and conditions of the repriced options, including vesting schedules and expiration dates under the 2019 Incentive Award Plan, remain unchanged and continue to depend on his ongoing service with the company.

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^*

Aranda Richard

(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)
	Chief Medical Officer

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)			562,500	(2)	01/01/2036	Common Stock	562,500	(1)	0	D
Stock Option (Right to Buy)	$1.13	03/19/2026		D(1)			572,000	(2)	03/03/2035	Common Stock	572,000	(1)	0	D
Stock Option (Right to Buy)	$0.97	03/19/2026		D(1)			487,500	(2)	01/01/2034	Common Stock	487,500	(1)	0	D
Stock Option (Right to Buy)	$0.838	03/19/2026		D(1)			162,500	(2)	11/19/2033	Common Stock	162,500	(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)			20,000	(2)	06/21/2031	Common Stock	20,000	(1)	0	D
Stock Option (Right to Buy)	$1.36	03/19/2026		D(1)			40,000	(2)	02/25/2031	Common Stock	40,000	(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)			30,000	(2)	03/25/2029	Common Stock	30,000	(1)	0	D
Stock Option (Right to Buy)	$0.45	03/19/2026		A(1)		562,500		(2)	01/01/2036	Common Stock	562,500	(1)	562,500	D
Stock Option (Right to Buy)	$0.45	03/19/2026		A(1)		572,000		(2)	03/03/2035	Common Stock	572,000	(1)	572,000	D
Stock Option (Right to Buy)	$0.45	03/19/2026		A(1)		487,500		(2)	01/01/2034	Common Stock	487,500	(1)	487,500	D
Stock Option (Right to Buy)	$0.45	03/19/2026		A(1)		162,500		(2)	11/19/2033	Common Stock	162,500	(1)	162,500	D
Stock Option (Right to Buy)	$0.45	03/19/2026		A(1)		157,500		(2)	03/19/2033	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)		20,000		(2)	06/21/2031	Common Stock	20,000	(1)	20,000	D
Stock Option (Right to Buy)	$0.45	03/19/2026		A(1)		40,000		(2)	02/25/2031	Common Stock	40,000	(1)	40,000	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)		30,000		(2)	03/25/2029	Common Stock	30,000	(1)	30,000	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 did the GOSS Form 4 filing disclose about Richard Aranda’s options?

The filing shows Chief Medical Officer Richard Aranda exchanged existing stock options for new ones with a lower exercise price of $0.45 per share. The number of options and all other terms, including vesting and expiration, remain the same under the 2019 Incentive Award Plan.

Was this a new stock option grant for Gossamer Bio (GOSS) CMO Aranda?

The transactions reflect a repricing rather than an entirely new award. Existing options were returned to the issuer and reissued at a reduced $0.45 exercise price, while keeping prior share amounts, vesting provisions, and expiration dates intact under the 2019 Incentive Award Plan.

How were Gossamer Bio CMO Richard Aranda’s stock options repriced?

On March 19, 2026, certain outstanding options were cancelled and replaced with options for the same number of underlying common shares at a new $0.45 exercise price. Footnotes state that vesting terms and option durations otherwise remain in full force and effect.

Did the GOSS Form 4 indicate any open-market stock sales or purchases?

No open-market trades were reported. The Form 4 lists dispositions to the issuer of existing stock options and corresponding acquisitions of repriced options. These are compensation-related adjustments rather than market purchases or sales of Gossamer Bio common stock.

What role does Gossamer Bio’s 2019 Incentive Award Plan play in this Form 4?

All affected stock options were granted under the 2019 Incentive Award Plan. The repricing only reduced each option’s exercise price to $0.45 per share, while leaving vesting schedules, term provisions, and service-based conditions from the original plan awards unchanged.

Are the repriced GOSS stock options subject to continued service requirements?

Yes. A footnote explains that the stock option award remains exercisable according to its existing vesting schedule, which is conditioned on Richard Aranda’s continued service with Gossamer Bio as of each applicable vesting date specified in the award agreement.