UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): April 3, 2023

GOSSAMER BIO, INC.

(Exact name of Registrant as Specified in Its Charter)

Delaware	001-38796	47-5461709
(State or Other Jurisdiction of Incorporation)	(Commission File Number)	(IRS Employer Identification No.)

3013 Science Park Road

San Diego, California, 92121

(Address of Principal Executive Offices) (Zip Code)

(858) 684-1300

(Registrant’s Telephone Number, Including Area Code)

N/A

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instructions A.2. below):

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class	Trading Symbol(s)	Name of each exchange on which registered
Common Stock, $0.0001 par value per share	GOSS	Nasdaq Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.  ☐

Item 8.01 Other Events.

On April 3, 2023, Gossamer Bio, Inc. (the “Company”) announced that the U.S. Food and Drug Administration (the “FDA”) has placed a partial clinical hold on all trials of GB5121, in response to serious adverse events that have been observed in the Phase 1b/2 STAR-CNS study, including atrial fibrillation, a sudden death event and a fatal intracranial hemorrhage. The Company previously announced on March 17, 2023 that it had paused enrollment of the Phase 1b/2 STAR-CNS Study based on the benefit / risk profile observed to date and a prioritization of resources to support the Company’s seralutinib program. Based on the foregoing factors, the Company has decided to terminate all ongoing studies and discontinue development of GB5121.

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

	GOSSAMER BIO, INC.
Date: April 3, 2023	By:	/s/ Christian Waage
		Christian Waage
		Executive Vice President, Technical Operations & Administration

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