Proxy Results (Form 8-K)

Item 5.07 Submission of Matters to a Vote of Security Holders.

Annual Meeting of Stockholders

On June 16, 2026, SELLAS Life Sciences Group, Inc. (the "Company") held its Annual Meeting of Stockholders ("Annual Meeting"). There were 115,511,771 shares of common stock, or approximately 62.59% of all outstanding shares, present in person or represented by proxy. At the Annual Meeting, the stockholders voted on the following five proposals and cast their votes as described below.

Proposal 1

The Company's stockholders re-elected each of the following nominees as a Class I director to the Board of the Company to hold office until the 2029 Annual Meeting of Stockholders and until their respective successors have been duly elected and qualified.

Proposal 2

The Company's stockholders ratified the appointment of Baker Tilly US, LLP (as the successor to Moss Adams LLP) as the Company's independent registered public accounting firm for the fiscal year ending December 31, 2026.

Proposal 3

The Company's stockholders approved an amendment to the Company's 2023 Amended and Restated Equity Incentive Plan (the "2023 Equity Plan") to increase the number of shares of common stock available for sale under the 2023 Equity Plan by 20,000,000.

Proposal 4

The Company's stockholders approved the non-binding, advisory resolution on the executive compensation of the Company's named executive officers.