JJP Biologics to Present Data Showing the Potential of Nebaprubart for Linear IgA Dermatosis (LAD) at Two Key Upcoming Scientific Conferences

• Positive interim data from Phase Ib proof-of-concept trial will be presented at the IPPF Scientific Symposium on Pemphigus and Pemphigoid and at EADV Congress 2026
• Data positions nebaprubart as a potential therapy across a broad range of IgA-mediated diseases

Warsaw, Poland – September 28, 2026 – JJP Biologics, ("JJPBio" or the "Company") a clinical-stage, immune-focused biotech that engineers precision antibodies to correct derailed immune pathways that drive autoimmune diseases and cancer, today announced that data on nebaprubart, its investigational first-in-class anti-CD89 antagonist, will be presented as an oral presentation at the IPPF Scientific Symposium on Pemphigus and Pemphigoid being held 28-29 September in Lübeck, Germany, and as a poster presentation at the European Academy of Dermatology and Venereology (EADV) Congress being held 30 September – 3 October in Vienna, Austria.

Both presentations report interim findings from the Company's ongoing open-label Phase Ib proof-of-concept trial of nebaprubart in patients with linear IgA dermatosis (LAD), a rare autoantibody-mediated blistering skin disease.

• IPPF Scientific Symposium on Pemphigus and Pemphigoid, Lübeck, Germany
  • Presenting author: Prof. Cezary Kowalewski, MD, PhD, sub-investigator of JJP Biologics' Phase 1b clinical trial, of the National Medical Institute of the Ministry of the Interior and Administration (PIM MSWiA), Warsaw
  • Presentation title: Nebaprubart in Linear IgA Bullous Dermatosis: Rapid Disease Control and Sustained Remission in an Open-Label Phase Ib Proof-of-Concept Study
  • Date: 29 September 2026, 13:50-14:50 CEST
  • Session: Session 6: Treatment of AIBD and Paediatrics.
    
    
• EADV Congress 2026, Vienna, Austria
  
  
  • Presenting author: Dawid Łyżwa, PhD, Head of Clinical Development at JJP Biologics
  • Presentation Title: Nebaprubart in Linear IgA Dermatosis: Rapid Disease Control and Sustained Remission in an Open-Label Phase Ib Proof-of-Concept Study
  • Date: 30 September 2026, 7:00AM CEST
  • Session: Autoimmune Disorders Part II
    
    

Sohail Ahmed, Chief Medical Officer of JJP Biologics, said: "We will share the interim data on nebaprubart for the first time at two leading autoimmune skin disease congresses, illustrating how the novel mechanism of our first-in-class anti-CD89 antagonist works in practice. Most current treatments for linear IgA dermatosis rely on broad immunosuppression, which carries its own burden of side effects and doesn't address the underlying mechanism. Nebaprubart is designed to block the IgA/CD89 interaction directly, and the presentations will show how that mechanism translates into patient outcomes."

Prof. Cezary Kowalewski, MD, PhD, sub-investigator of JJP Biologics' Phase 1b clinical trial of nebaprubart for LAD, of the National Medical Institute of the Ministry of the Interior and Administration (PIM MSWiA), Warsaw, said: "Patients with linear IgA dermatosis have very limited options today. Corticosteroids and dapsone carry toxicity risks, and neither addresses the underlying mechanism. There is a need for a mechanism-specific alternative that gives patients and physicians a rational alternative to years of off-label, broadly immunosuppressive treatment. I look forward to presenting the data at IPPF and discussing what this mechanism could mean for how we treat this disease going forward."

The Phase 1b trial (registered in the EU Clinical Trials Information System (CTIS) under EU Trial Number 2023-508661-33-00) is an open-label trial designed to evaluate safety and tolerability along with pharmacokinetic, immunogenicity, and exploratory efficacy measures including disease activity, blister formation, severity of pruritus and quality of life. The positive interim results from the trial were previously announced by JJPBio via a press release in June 2026.

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About JJP Biologics (JJPBio)

JJP Biologics is a clinical-stage biotech that leverages its in-depth understanding of immune pathway science in autoimmune diseases and cancer. Starting from deep mechanistic insights, JJPBio engineers antibodies that are built-to-order, designed to restore immune balance and deliver better disease control for patients with significant unmet need, because we believe that we can do better for patients.

JJPBio is the first company to generate clinical validation of the IgA/CD89 axis, establishing first-mover advantage in a disease area with broad implications across autoimmune conditions including IgA nephropathy, rheumatoid arthritis, lupus, and celiac disease. Our immuno-oncology program targets the CD270/HVEM checkpoint pathway in cancer.

Backed by the long-term, socially responsible capital of the Starak family and the Polpharma Group, JJPBio operates with the scientific freedom and financial stability to pursue mechanisms others simply cannot.

JJP Biologics: We restore. We don't deplete. We work smarter.

About nebaprubart (JJP-1212)

Nebaprubart is a first-in-class IgG4-κ CD89 antagonist that is being developed to treat a wide range of autoimmune, inflammatory, and fibrotic diseases where IgA antibodies are known to have significant pathogenic involvement (e.g., rheumatoid arthritis, systemic lupus erythematosus, idiopathic pulmonary fibrosis, dermatitis herpetiformis, inflammatory bowel disease, IgA nephropathy, and IgA vasculitis). Nebaprubart was designated an Orphan Medicinal Product in October 2022 by the European Commission for the treatment of Linear IgA Disease. An open-label trial with nebaprubart for this indication is ongoing.