X0508 4 2026-02-12 0001798749 Jade Biosciences, Inc. JBIO 0001884087 Balta Elizabeth C/O JADE BIOSCIENCES, INC. 221 CRESCENT ST., BLDG. 23, STE. 105 WALTHAM MA 02453 false true false false See Remarks false Common Stock 2026-02-12 4 A false 28125 0 A 28125 D Stock Option (Right to Buy) 14.81 2026-02-12 4 A false 168750 0 A 2036-02-11 Common Stock 168750 168750 D Represents restricted stock units ("RSUs"). 1/4 of the total number of RSUs granted shall vest on each of the first four anniversaries of February 15, 2026, the vesting commencement date, subject to the Reporting Person's continued service through each vesting date. Each RSU represents a contingent right to receive one share of common stock of the Issuer. This option represents a right to purchase shares of the Issuer's common stock, one quarter of which will vest on February 15, 2027, with the remaining three quarters vesting in equal monthly installments over the following three years, subject to the Reporting Person's continued service to the Issuer on each such vesting date. Chief Legal Officer and Corporate Secretary /s/ Elizabeth Balta 2026-02-13