JADE101 is designed with ultra-high binding affinity to selectively block APRIL, a key driver of pathogenic IgA production in IgAN, a chronic autoimmune disease that frequently affects young adults and can lead to end-stage kidney disease over a patient's lifetime. These results will be presented in a focused oral session during the 63rd European Renal Association (ERA) Congress, taking place in Glasgow, Scotland, from June 3-6, 2026.

"IgA is a critical biomarker in IgA nephropathy, with strong evidence linking early and sustained IgA reductions to later reductions in proteinuria, a key marker of disease activity and long-term kidney risk," said Jonathan Barratt, PhD, Mayer Professor of Renal Medicine at the University of Leicester. "With JADE101, IgA reductions of approximately 70% sustained at 12 weeks in healthy volunteers are both biologically and clinically meaningful, offering the potential to deliver more substantial clinical outcomes and extend the dosing interval beyond currently available therapies. JADE101's potential to deliver sustained disease control with less frequent dosing could represent a significant advance in treating a disease that often begins in young adulthood and requires lifelong management."

"The interim results from this Phase 1 trial showed that JADE101 drove rapid, deep and durable IgA reductions in healthy volunteers, with favorable tolerability and the potential for dosing every 12 weeks," said Tom Frohlich, Chief Executive Officer of Jade Biosciences. "JADE101 was designed with ultra-high potency, selective APRIL inhibition and extended half-life to achieve a differentiated and patient-friendly profile. These data position JADE101 as a potentially best-in-class anti-APRIL therapy at the forefront in a large and growing market. With the goal of bringing this therapy to patients as quickly as possible, we have advanced JADE101 into a Phase 2 trial and plan to initiate a Phase 3 registrational trial in the first half of 2027."

JADE101 Phase 1 Trial Design

The JADE101 Phase 1 trial is a double-blind, placebo-controlled study evaluating the safety and tolerability, pharmacodynamics (PD) and pharmacokinetics (PK) of single ascending subcutaneously administered doses of JADE101 in healthy volunteers.

As of the data cutoff of April 14, 2026, the trial has enrolled 32 healthy adult volunteers across four dose cohorts, with eight participants per cohort randomized in a 6:2 ratio to receive JADE101 or placebo. Evaluated doses included single subcutaneous administrations of 175 mg, 350 mg, 700 mg, and 1,400 mg.

Key findings at this interim analysis included:

Depth and Duration of IgA Reductions Driven by Potent Free APRIL (fAPRIL) Suppression

  • Mean IgA reductions reached approximately 70% from baseline and were sustained at 12 weeks at the 700 mg dose; this dose is anticipated to reflect the steady-state IgA responses in IgAN patients with the planned JADE101 dosing strategy
    • IgA-lowering effect observed to be deeper, faster, and more durable following a single dose of JADE101 than with first-generation anti-APRIL or dual APRIL/BAFF inhibitors
    • Greater than 70% IgA reductions simulated at steady-state with a single subcutaneous injection of 350 mg of JADE101 every 12 weeks (Q12W) following one 700 mg induction dose, which could support best-in-class clinical activity with a convenient dosing regimen of only four injections per year
    • IgA-lowering potency estimated to be approximately 379-fold higher than sibeprenlimab and approximately 26-fold higher than povetacicept
  • JADE101 achieved rapid, complete and durable suppression of fAPRIL, consistent with the femtomolar APRIL binding affinity of JADE101



     

Favorable Safety Profile; Well-Tolerated Across All Evaluated Subcutaneous Dose Levels

  • Single subcutaneous doses of JADE101 up to 1,400 mg were well tolerated with an observed safety profile generally consistent with the anti-APRIL class
  • The most common treatment-emergent adverse events in the pooled safety analysis occurring in more than two participants were headache, upper respiratory tract infection, injection site erythema, oropharyngeal pain and pyrexia
  • There were no serious adverse events and no adverse events leading to study discontinuation
  • There were no cases of hypogammaglobulinemia, defined as IgG less than or equal to 3 g/L



     

Differentiated Pharmacokinetic Profile Supports Potential for Convenient Dosing

  • JADE101 demonstrated dose-dependent increases in exposure across evaluated dose levels
  • Half-life at steady state for JADE101 was approximately 8.7-fold longer than reported for povetacicept and approximately 2.6-fold longer than reported for sibeprenlimab
  • Target-mediated drug disposition threshold with JADE101 is estimated to be approximately 2.5-fold lower than reported for sibeprenlimab
  • No apparent impact of anti-drug antibodies on PK or PD was observed



     

Phase 2 IgAN Trial Underway with Phase 3 Registrational Trial Planned for First Half of 2027

JUNIPER is an ongoing Phase 2 clinical trial evaluating JADE101 in participants with IgAN. The open-label trial is expected to enroll approximately 30 participants. Participants are expected to receive a 700 mg induction dose of JADE101 at treatment onset followed by maintenance doses of 350 mg starting at Week 4 and subsequently either every 8 weeks (n=15) or every 12 weeks (n=15). Evaluating both dose intervals is intended to support accelerated Phase 3 initiation and satisfy global regulatory expectations for dose finding. The primary objectives of the trial are to evaluate the safety and tolerability of JADE101. Secondary and exploratory objectives include changes in 24-hour urine protein-to-creatinine ratio (UPCR-24), including the proportion of participants achieving UPCR-24 levels below 0.5 g/day and 0.3 g/day, renal function as measured by estimated glomerular filtration rate (eGFR), and hematuria resolution over time. Interim clinical data are anticipated in 2027.

Jade plans to initiate a registrational Phase 3 clinical trial in the first half of 2027, pending Food and Drug Administration requirements.