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): October 12, 2023

SELLAS Life Sciences Group, Inc.

(Exact name of registrant as specified in its charter)

Delaware	001-33958	20-8099512
(State or other jurisdiction of incorporation or organization)	(Commission File Number)	(I.R.S. Employer Identification No.)

	7 Times Square, Suite 2503 New York, NY 10036
	(Address of Principal Executive Offices) (Zip Code)

Registrant’s telephone number, including area code: (646) 200-5278

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligations of the registrant under any of the following provisions:

	¨	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	SLS	The Nasdaq Stock Market LLC

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 October 12, 2023, SELLAS Life Sciences Group, Inc. (the “Company”) issued a press release (the “Press Release”) providing an update on its Phase 3 REGAL Clinical Trial for Galinpepimut-S in Acute Myeloid Leukemia. A copy of the Press Release is attached hereto as Exhibit 99.1 and is incorporated by reference herein.

Item 9.01.

Financial Statements and Exhibits.

(d) Exhibits

Exhibit Number		Description
99.1		Press Release dated October 12, 2023
104		Cover Page Interactive Data File (embedded within the Inline XBRL document)

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 hereunto duly authorized.

		SELLAS Life Sciences Group, Inc.

Date:	October 13, 2023	By:		/s/ Barbara A. Wood
			Name:	Barbara A. Wood
			Title:	Executive Vice President, General Counsel and Corporate Secretary