Corporate Action, Amendments to Bylaws (Form 8-K)

To the extent required by Item 3.03 of Form 8-K, the disclosures set forth under the heading "Amended and Restated Articles of Incorporation" in Item 5.03 below are incorporated by reference into this Item 3.03.

Amended and Restated Articles of Incorporation

Jade Biosciences, Inc. (the "Company") held its 2026 Annual Meeting of Stockholders (the "2026 Annual Meeting") on June 9, 2026. At the 2026 Annual Meeting, as described below under Item 5.07, the stockholders of the Company approved an amendment to the Company's Articles of Incorporation to waive jury trials in certain circumstances (the "Amendment"). The Amendment became effective upon the Company's filing of Amended and Restated Articles of Incorporation, including the Amendment as a new Article X, with the Nevada Secretary of State on June 10, 2026 (the "Amended and Restated Articles"). The foregoing description of the Amendment is qualified in its entirety by reference to the full text of the Amended and Restated Articles, a copy of which is attached as Exhibit 3.1 hereto and is incorporated herein by reference.

Amended and Restated Bylaws

On June 8, 2026, the Board of Directors (the "Board") of the Company approved and adopted amended and restated bylaws (the "Amended and Restated Bylaws"), which became effective on June 9, 2026, to make certain technical, modernizing and clarifying changes consistent with the current Nevada Revised Statutes (the "NRS"). Among other things, the amendments effected by the Amended and Restated Bylaws remove the requirement to prepare a list of stockholders entitled to vote at each stockholder meeting and make it available to stockholders for ten days prior to the meeting. In addition, the amendments make certain changes to better align with the language of provisions of the NRS that: permit stockholder and Board meetings to be held virtually and by remote communication; provide that a record date for stockholders entitled to notice of and to vote at any meeting of stockholders applies to any postponement of such meeting unless the Board fixes a new record date or the meeting is postponed to a date more than 60 days later than the original meeting date, in which case the Board shall fix a new record date; and set out the voting standard for stockholder votes other than for the election of directors ("number of votes cast in favor of the action exceeds the number of votes cast in opposition to the action" instead of "affirmative vote of at least a majority of the votes cast").

The foregoing description of the Amended and Restated Bylaws does not purport to be complete and is qualified in its entirety by reference to the full text of the Amended and Restated Bylaws attached hereto as Exhibit 3.2 (clean version) and Exhibit 3.3 (marked version), which are incorporated herein by reference.