Amendment to Schedule 13D Filing for Gossamer Bio, Inc.

This filing is an Amendment No. 1 to a Schedule 13D, originally filed on July 28, 2023, concerning the Common Stock of Gossamer Bio, Inc. The amendment supplements the original filing. On February 23, 2026, Growth Equity Opportunities 18 VGE, LLC (GEO) completed open market sales of 17,093,034 shares of Common Stock at a weighted average price of $0.3906 per share. As of February 23, 2026, GEO beneficially holds 3,065,134 shares of Common Stock underlying GEO Warrants, representing 1.7% of the class. Other reporting persons, including NEA 18 Venture Growth Equity, L.P., NEA Partners 18 VGE, L.P., NEA 18 VGE GP, LLC, and several individuals (Ali Behbahani, Carmen Chang, Anthony A. Florence, Jr., Mohamad H. Makhzoumi, Edward T. Mathers, Scott D. Sandell, Paul Walker, and Rick Yang), may also be deemed to beneficially own these shares. The filing includes an agreement regarding the joint filing of Schedule 13D and powers of attorney authorizing representatives to sign on behalf of the reporting persons.