JBIO: Phase 2 JUNIPER Initiation Keeps JADE101 on Schedule; ERA Abstract Qualitatively Supportive Ahead of June 5 Phase 1 Data Release; Reiterate Buy

Research evidence excerpt

JBIO: Phase 2 JUNIPER Initiation Keeps JADE101 on Schedule; ERA Abstract Qualitatively Supportive Ahead of June 5 Phase 1 Data Release; Reiterate Buy

FLASH NOTE

May 26, 2026

Vamil Divan, M.D. vamil.divan@guggenheimpartners.com JBIO: Phase 2 JUNIPER Initiation Keeps JADE101

212 823 6543 on Schedule; ERA Abstract Qualitatively Supportive

Arseniy Shabashvili

arseniy.shabashvili@guggenheimpartners.com Ahead of June 5 Phase 1 Data Release; Reiterate

212 699 1971 Buy Daniel Krizay, Ph.D.

daniel.krizay@guggenheimpartners.com

212 823 6561 Key Message: Jade Biosciences (JBIO) announced this morning that the first participant

Edouard Mullarky, Ph.D. has been dosed in JUNIPER, the open-label Phase 2 trial of JADE101 (the company's

edouard.mullarky@guggenheimpartners.com fully human anti-APRIL monoclonal antibody) in immunoglobulin A nephropathy (IgAN),

212 518 9579 with interim data expected in 2027. JUNIPER will enroll approximately 30 IgAN

participants and evaluate safety and tolerability, change in urine protein-to-creatinine

ratio (UPCR), estimated glomerular filtration rate (eGFR), and resolution of hematuria.

Separately, initial European Renal Association (ERA) 2026 Meeting abstracts have been

released, including an abstract for the Phase 1 single-ascending-dose healthy volunteer JBIO

Jade Biosciences, Inc. study of JADE101 (175, 350, 700, and 1,400 mg subcutaneous doses) ahead of the

Sector: Biotechnology detailed interim analysis to be presented on Friday, June 5. The abstract reports JADE101

as generally safe and well-tolerated with no dose-limiting toxicities, dose-dependent

Company Update and extended PK exposure, and substantial and dose-dependent reductions in free

Share Price $22.21 APRIL and serum IgA, but does not disclose the quantitative details.