Material Agreement Form 8 K

Item 1.01 Entry into a Material Definitive Agreement.

On October 3, 2024, SELLAS Life Sciences Group, Inc. (the "Company"), as subtenant, entered into a Letter Agreement with Times Square Tower Associates LLC (the "Sublandlord") relating to a certain sublease (as amended) of certain premises located at Times Square Tower, 7 Times Square, New York, New York (the "Sublease"). The Letter Agreement provides for the extension of the expiration date of the Sublease from September 30, 2025 to September 30, 2026. The annual rent remains unchanged.

The foregoing description of the Letter Agreement is qualified in its entirety by reference to the Letter Agreement, which is filed as Exhibit 10.1 hereto and incorporated herein by reference.