Gossamer Bio, Inc. — Form 8-K

Gossamer Bio adopted amended and restated bylaws effective September 3, 2026. Key changes include: (1) stockholder action by written consent eliminated—all stockholder actions now require duly called meetings; (2) advance notice windows for stockholder proposals and director nominations tightened to 90–120 days before annual meetings with detailed disclosure requirements; (3) federal district courts established as exclusive forum for Securities Act claims; (4) director removal now requires two-thirds vote of outstanding shares rather than simple majority; (5) extensive indemnification provisions expanded for directors and officers. No specific dollar amounts, counterparties, or share counts are disclosed in these governance revisions.