Management Change/Compensation (Form 8-K)

On March 31, 2026, the Board of Directors (the "Board") of Jade Biosciences, Inc. (the "Company") approved the Jade Biosciences, Inc. 2026 Employment Inducement Stock Incentive Plan (the "2026 Inducement Plan"). The terms of the 2026 Inducement Plan are substantially similar to the terms of the Company's 2025 Stock Incentive Plan with the exception that incentive stock options may not be issued under the Inducement Plan and awards under the Inducement Plan may only be issued to eligible recipients under the applicable Nasdaq rules. The 2026 Inducement Plan was adopted by the Board without stockholder approval pursuant to Rule 5635(c)(4) of the Nasdaq Listing Rules.

The Board has initially reserved 1,750,000 shares of the Company's common stock for issuance pursuant to awards granted under the 2026 Inducement Plan. In accordance with Rule 5635(c)(4) of the Nasdaq Listing Rules, awards under the 2026 Inducement Plan may only be made to an employee who has not previously been an employee or member of the board of directors of the Company or any subsidiary, or following a bona fide period of non-employmentby the Company or a subsidiary, if he or she is granted such award in connection with his or her commencement of employment with the Company or a subsidiary and such grant is an inducement material to his or her entering into employment with the Company or such subsidiary.

The Company intends to file a complete copy of the 2026 Inducement Plan and the forms of stock option agreement and restricted stock unit agreement to be used thereunder as exhibits to the Company's Quarterly Report on Form 10-Qfor the quarter ended March 31, 2026. The above summary of the 2026 Inducement Plan does not purport to be complete and is qualified in its entirety by reference to such exhibits.