SEC FORM 4 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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checkbox unchecked Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
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1. Name and Address of Reporting Person*
Peterson Caryn

(Last) (First) (Middle)
3115 MERRYFIELD ROW, SUITE 120

(Street)
SAN DIEGO CA 92121

(City) (State) (Zip)
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
checkbox checked Officer (give title below) Other (specify below)
EVP, Regulatory Affairs
3. Date of Earliest Transaction (Month/Day/Year)
03/19/2026
4. If Amendment, Date of Original Filed (Month/Day/Year)
6. Individual or Joint/Group Filing (Check Applicable Line)
checkbox checked 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
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).
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