Jade Biosciences Announces First Cohort Dosed in Phase 1 Healthy Volunteer Clinical Trial of JADE101, a Novel and Potentially Best-in-Class Anti-APRIL Monoclonal Antibody Being Evaluated for the Treatment of IgA Nephropathy

• Selective APRIL inhibition has shown disease-modifying potential in IgAN patient clinical trials
• JADE101 has shown ultra-high binding affinity and a differentiated pharmacokinetic and pharmacodynamic profile preclinically, supporting the potential for patient-friendly subcutaneous dosing every eight weeks or longer
• Interim, biomarker-rich Phase 1 healthy volunteer data are expected in the first half of 2026, and are anticipated to define dose and dosing interval selection based on biomarker responses associated with optimal clinical activity in IgAN patients

SAN FRANCISCO and VANCOUVER, British Columbia, Sept. 02, 2025 (GLOBE NEWSWIRE) — Jade Biosciences, Inc. (“the Company” or “Jade”), (Nasdaq: JBIO), a clinical-stage biotechnology company focused on developing best-in-class therapies for autoimmune diseases, today announced that it has dosed the first cohort of participants in a Phase 1 healthy volunteer trial of JADE101. JADE101 is the Company’s investigational monoclonal antibody designed to selectively inhibit the activity of A PRoliferation-Inducing Ligand (APRIL) in patients with immunoglobulin A nephropathy (IgAN). The Company expects interim Phase 1 clinical data in the first half of 2026.

“We believe the anti-APRIL class is poised to be the foundational treatment for patients with IgAN, an autoimmune kidney disease that leads to end-stage kidney disease over the lifetime of most patients,” said Andrew King, Ph.D., Chief Scientific Officer and Head of R&D at Jade Biosciences. “JADE101 has a differentiated preclinical profile, demonstrating femtomolar binding affinity to APRIL and deep and prolonged IgA reductions in non-human primates. These properties could lead to potentially capturing the full efficacy of the anti-APRIL mechanism and offering the most convenient dosing schedule in the class—an important consideration for a lifelong disease that typically affects otherwise healthy young adults. Our interim healthy volunteer data are expected to be highly informative, providing readouts on APRIL and IgA biomarkers, and are anticipated to define dose and dosing interval selection for later-stage IgAN patient studies.”

The Phase 1 clinical trial is a randomized, double-blind, placebo-controlled study evaluating single ascending subcutaneous doses of JADE101 in healthy adult volunteers. The trial will assess the safety, tolerability, pharmacokinetics and pharmacodynamics of JADE101. More information on the JADE101 Phase 1 trial is available on ClinicalTrials.gov.

About JADE101

JADE101 is a fully human monoclonal antibody that selectively blocks APRIL with ultra-high binding affinity and is engineered for half-life extension. Preclinical studies demonstrated potent, sustained IgA suppression after a single dose in non-human primates, with a serum half-life of approximately 27 days. JADE101 was designed to avoid formation of high molecular weight immune complexes, with the goal of supporting predictable pharmacokinetics and reduced immunogenicity risk. Its differentiated pharmacokinetic and pharmacodynamic profile supports the potential for infrequent and convenient subcutaneous dosing, an important consideration for a condition often diagnosed in young adulthood and potentially requiring life-long treatment.

About Jade Biosciences, Inc. 

Jade Biosciences is a clinical-stage biotechnology company focused on developing best-in-class therapies that address critical unmet needs in autoimmune diseases. Jade’s lead candidate, JADE101, targets the cytokine APRIL, and is currently being evaluated in a Phase 1 clinical trial for the treatment of immunoglobulin A nephropathy. Jade’s pipeline also includes a second development candidate, JADE201, and an undisclosed antibody discovery program, JADE-003, both currently in preclinical development. Jade was launched based on assets licensed from Paragon Therapeutics, an antibody discovery engine founded by Fairmount. For more information, visit JadeBiosciences.com and follow the Company on LinkedIn. 

Forward-Looking Statements 

Certain statements in this communication, other than purely historical information, may constitute “forward-looking statements” within the meaning of the federal securities laws, including for purposes of the “safe harbor” provisions under the Private Securities Litigation Reform Act of 1995. These forward-looking statements include, but are not limited to, express or implied statements relating to Jade’s expectations, hopes, beliefs, intentions or strategies regarding the future of its pipeline and business including, without limitation, the expected timeline for interim data from the Phase 1 clinical trial of JADE101, plans for future clinical trials, the potential for the anti-APRIL class to become the foundational treatment for patients with IgAN, the potential of JADE101 and Jade’s other product candidates to become best-in-class therapies and their potential therapeutic uses, efficacy, dosing, safety and market opportunities. The words “opportunity,” “potential,” “milestones,” “pipeline,” “can,” “goal,” “strategy,” “target,” “anticipate,” “achieve,” “believe,” “contemplate,” “continue,” “could,” “estimate,” “expect,” “intends,” “may,” “plan,” “possible,” “project,” “should,” “will,” “would” and similar expressions (including the negatives of these terms or variations of them) may identify forward-looking statements, but the absence of these words does not mean that a statement is not forward-looking. These forward-looking statements are based on current expectations and beliefs concerning future developments and their potential effects. There can be no assurance that future developments affecting Jade will be those that have been anticipated. These forward-looking statements involve a number of risks, uncertainties (some of which are beyond Jade’s control) or other assumptions that may cause actual results or performance to be materially different from those expressed or implied by these forward-looking statements. These risks and uncertainties include, but are not limited to, the risks that the Phase 1 clinical trial of JADE101 and any future clinical trials may be delayed or may not demonstrate desirable safety and/or efficacy; Jade may experience unanticipated costs, difficulties or delays in the product development process; Jade’s product candidates may fail in development, may not receive required regulatory approvals, or may be delayed to a point where they are not commercially viable; enrollment or regulatory challenges; risks associated with dependence on third-parties for the development, manufacture and supply of JADE101; and the other risks, uncertainties and factors more fully described in Jade’s most recent filings with the Securities and Exchange Commission (including the Quarterly Report on Form 10-Q for the quarter ended June 30, 2025). Should one or more of these risks or uncertainties materialize, or should any of Jade’s assumptions prove incorrect, actual results may vary in material respects from those projected in these forward-looking statements. You should not place undue reliance on forward-looking statements in this communication, which speak only as of the date they are made and are qualified in their entirety by reference to the cautionary statements herein. Jade does not undertake or accept any duty to release publicly any updates or revisions to any forward-looking statements. This communication does not purport to summarize all of the conditions, risks and other attributes of an investment in Jade.  

Jade Biosciences Contact 

Priyanka Shah 
Media@JadeBiosciences.com 
IR@JadeBiosciences.com 
908-447-6134