Purespring to present three posters at the American Society of Nephrology Kidney Week 2025

• New information to be presented on the study design and methodology of Purespring’s Phase I/II trial of PS-002, an AAV-based therapy delivering the complement factor I to podocytes in patients with IgA nephropathy
• Patient and carer feedback from insights sessions on gene therapy study concepts in nephrology will be presented
• Purespring co-author paper with real world evidence on epidemiological prevalence data of NPHS2 pathogenic variants across global populations

London – 4 November 2025 – Purespring Therapeutics, a precision nephrology company leading the development of targeted, first-in-class genetic therapies to preserve kidney function, today announced that it will be presenting three scientific posters at the American Society of Nephrology (ASN) Kidney Week 2025, held from November 5–9, 2025, in Houston, Texas.

The first poster will outline the design of Purespring's Phase I/II trial of PS-002, an AAV-based gene therapy that delivers the complement factor I (CFI) gene to podocytes in patients with IgA nephropathy (IgAN). This approach has the potential to alleviate complement driven glomerular diseases at the site of disease without affecting systemic complement activation, with a single PS-002 dose expected to confer long-term benefits enabling non-dividing podocytes to produce complement modulating CFI locally.

Session title: Informational Posters – 2
Poster title: Phase 1/2 Trial of PS-002, an AAV-based Therapy Delivering the Complement Factor I Gene to Podocytes in IgA nephropathy
Presenter: Fredrik Erlandsson, Chief Medical Officer
Authors: Pille Harrison, Richard Layfayette, Smeeta Sinha, Ian Roberts, Moin Saleem, Charlotte J Smerdon, Alicia Rowland, Fredrik Erlandsson, Jonathan Barratt
Date & time: 7 November 2025, 10:00 am-12:00 pm CST
Poster Board #: INFO15-FR

The second poster will outline feedback from insight sessions with current IgAN patients and carers in the US and UK. These sessions, conducted by the IgA Nephropathy Foundation and the National Institute for Health and Care Research, explored the concept of a nephrology gene therapy study concept, gathering input to help optimise clinical trial design and inform future development of PS-002 and other planned gene therapies for renal disorders. There was high interest in a ‘once-and-done’ nature and novel approach to therapy.

Session title: Glomerular Research: Design, Registries, Surveys, and Epidemiology
Poster title: Patient and Carer Feedback on a Nephrology Gene Therapy Study Concept
Presenter: Fredrik Erlandsson, Chief Medical Officer
Author: Pille Harrison, John Marsala, Heather K Harper, Davina Munday, Emily Pickering, Charlotte J Smerdon, Alicia Rowland, Fredrik Erlandsson
Date & Time: 8 November 2025, 10:00 am-12:00 pm CST
Poster Board #: SA-PO0776

The third poster from the University of Bristol, with co-authors from Purespring, will present comprehensive epidemiological data on NPHS2 pathogenic variants from over 1.2 million genomes to estimate pathogenic genotype frequencies of NPHS2 in the US, UK, Europe and Japan across multiple data sources. It also explores how these impact on presentation and disease progression of focal segmental glomerulosclerosis (FSGS) and steroid-resistant nephrotic syndrome (SRNS).

Session title: Monogenic Kidney Diseases: Glomerular
Poster title: Pathogenic NPHS2 Variants Predominantly Cause Adult-Onset FSGS in the United States While Childhood-Onset Disease Predominates in Europe and East Asia
Presenter: Moin Saleem, Co-founder & Chief Scientific Advisor
Author: Moin A Saleem, Wen Y Ding, Karen Malone, Dinah Clark, Radko Komers, Pille Harrison, Fredrik Erlandsson
Date & Time: 6 November 2025, 10:00 am-12:00 pm CST
Poster Board #: TH-PO0610

In August 2025, Purespring received UK Clinical Trial Authorisation for its Phase I/II trial of PS-002 in patients with IgAN. This followed an earlier announcement in July 2025 confirming that the Company had received IND clearance from the U.S. Food and Drug Administration (FDA).

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For further information, contact:

Purespring:

contact@purespringtx.com
+44 (0)20 3855 6324
LinkedIn

ICR Healthcare:

Amber Fennell, Sarah Elton-Farr
purespring@icrhealthcare.com

Notes to Editors

About Purespring:

Purespring Therapeutics is a clinical-stage precision nephrology company leading the development of targeted, first-in-class genetic therapies to preserve kidney function. Through its proprietary GlomThera™ platform, Purespring is able to deliver genetic therapies directly to the podocyte, offering a novel approach to the treatment of kidney diseases.

Purespring’s pipeline targets multiple renal indications with significant unmet medical need. The Company’s lead programme, PS-002, offers a highly differentiated approach for patients with IgA nephropathy (IgAN). By precisely targeting the site of disease, Purespring aims to transform the trajectory of kidney disease so patients can live fuller, healthier lives.

Purespring is backed by leading biotech investors, including Syncona Limited, Sofinnova Partners, Gilde Healthcare, Forbion, and the British Business Bank and has raised £115m ($150m) to date.

For more information please visit: purespringtx.com and follow us on LinkedIn.

About IgAN:

IgA nephropathy (IgAN) is the most common primary glomerulonephritis worldwide, with an estimated global prevalence of 2.5 per 100,000 individuals. It is a chronic, progressive autoimmune disease characterised by the deposition of immunoglobulin A (IgA) in the glomeruli of the kidney, leading to complement activation, persistent inflammation, tissue injury and progressive loss of kidney function. IgAN often presents in adolescents and young adults with haematuria, proteinuria, and hypertension. Approximately 20–40% of patients experience progressive loss of kidney function, leading to end-stage kidney disease within 20 years of diagnosis. High-risk patients may require dialysis or transplantation in as few as five years.

Current and other planned therapeutic approaches for IgAN are not sufficient for all patients and can pose tolerability challenges, underscoring the urgent need for disease-modifying and kidney targeted therapies.