Purespring Therapeutics receives UK CTA approval for Phase I/II clinical trial of PS-002 in patients with primary IgA nephropathy (IgAN)

• First patient in Phase I/II clinical trial expected to be enrolled in Q4 2025
• UK Clinical Trial Application (CTA) approval shortly follows U.S. IND clearance and granting of European Medicine Agency (EMA) orphan drug designation, enabling readiness for initiation across sites in both the U.S. and Europe
• PS-002, Purespring’s lead precision nephrology programme, targets the complement pathway known to be a driver of IgA nephropathy and is supported by a wealth of preclinical data

London – 5 August 2025 - Purespring Therapeutics, a precision nephrology company focused on transforming the treatment of kidney diseases, today announces that its UK Clinical Trial Application (CTA) for a planned Phase I/II study of PS-002, Purespring’s lead programme, in patients with IgA nephropathy (IgAN) has been approved by the UK Medicines and Healthcare products Regulatory Agency (MHRA), the NHS Health Research Authority (HRA) and Research Ethics Committee (REC).

“The CTA approval for our Phase I/II clinical trial of PS-002 represents another key milestone as we complete our transition to a clinical-stage precision nephrology company,” said Haseeb Ahmad, Purespring’s Chief Executive Officer. “Building on the recent FDA IND clearance and EMA orphan drug designation, this further validates the potential of our podocyte-targeting approach to go beyond symptom management and directly target kidney disease at its source. Looking ahead, we are committed to working closely with regulators and sites across the U.S. and Europe with the view to expand the therapeutic options available for people living with IgAN.”

PS-002 was developed to target the underlying cause of many kidney diseases by modulating complement activation in the kidney via precision targeting of podocytes. The programme is initially focused on the treatment of IgA nephropathy (IgAN), a rare and chronic autoimmune kidney disease that primarily affects young adults. In IgAN, aberrant immunoglobin A (IgA) protein becomes trapped in the kidney’s filters, known as the glomeruli, causing complement activation, inflammation, damage and scarring. A significant proportion of affected patients will go on to develop kidney failure despite currently available therapies.

The Phase I/II clinical trial, which is expected to enroll its first patient in Q4 2025, will evaluate local administration of PS-002 to treat IgAN. In the Phase 1 part of the Phase I/II study, the main read-outs will be safety parameters, which, together with efficacy biomarkers, will be leveraged to select a dose for the Phase 2 part of the study. This second phase will be used to further define the safety profile and provide early markers of efficacy. Enabled by this latest regulatory approval and the recent U.S. IND clearance, as announced in July 2025, the Phase I/II study will recruit patients across the U.S. and Europe.

For further information, contact:

Purespring:

Peter Mulcahy
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 is developing therapies to halt or prevent kidney disease, one of humankind’s most poorly treated disease areas.

Founded on the work of Professor Moin Saleem, Professor of Paediatric Renal Medicine at the University of Bristol, Purespring is the first company to successfully treat kidney disease by targeting the podocyte, a specialised cell that is implicated in the majority of renal disease. Purespring’s platform approach enables streamlined gene therapy development for both acquired and genetic renal diseases, offering the potential to halt, reverse and even cure both rare and common kidney diseases.

The Company currently has a pipeline of programmes in development including the lead asset for treatment of IgA Nephropathy (IgAN) and other complement mediated kidney disease. The Company also has programmes for disease caused by mutations in the gene NPHS2, as well as other monogenic glomerular kidney diseases.

Based in London, the Purespring team combines world-leading expertise in podocyte biology and kidney disease with a wealth of experience in gene therapies, anchored in a culture of diversity, creativity and delivery.

Purespring is backed by leading biotech investors, including Syncona Limited, Sofinnova Partners, Gilde Healthcare, Forbion, and the British Business Bank and has raised £115m ($149m) to date.

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