Purespring Therapeutics has secured £80m ($105m) to kick start a Phase I/II trial of its experimental adeno-associated viral (AAV) gene therapy in a kidney disease.
The London-based biotech’s lead asset PS-002 will be investigated for IgA nephropathy (IgAN), an autoimmune and kidney disease where too much immunoglobulin A (IgA) protein stays in the kidneys. The condition causes inflammation and can lead to end-stage renal disease.
PS-002 is an experimental AAV gene therapy designed to target podocytes, specialised cells critical for proper kidney function. In IgAN, immune complexes damage these cells, leading to protein leakage and kidney dysfunction. Purespring’s portfolio also includes a programme targeting nephrotic syndrome, named PS-001, and another focused on an undisclosed glomerular kidney disease programme.
Purespring showcased preclinical data of its PS-001 therapy at the European Renal Association (ERA) Congress in May 2024. The data showed that transgenes can be efficiently targeted to podocytes to replace defective genes or to use the podocyte as a protein factory to modulate kidney biology.
The Series B funding round was led by Sofinnova Partners in collaboration with Gilde Healthcare, Forbion, British Patient Capital and founding investor Syncona. Purespring launched out of Syncona in 2021 with $45m Series A funding under its belt. The company has a ‘gene search engine’ platform, dubbed FunSel, which selects the most effective treatments for diseases from a large library of AAV vectors, without focusing on specific genes or mechanisms.
The IgAN field has generated a wave of attention in the last few years, with a flurry of M&As to back it up. In August 2023, pharma giant Novartis bought Chinook Therapeutics in a $3.2bn deal where it acquired two drugs, atrasentan and zigakibart. Both candidates are currently being investigated in Phase III clinical trials for IgAN (NCT04573478 and NCT05852938).
Vertex Pharmaceuticals and Biogen followed suit, inking deals with Alpine Immune Sciences and Human Immunology Biosciences, respectively. The deals, both worth more than $1bn, saw the companies inherit assets set to treat IgAN.
In the announcement accompanying the funding, Purespring’s CEO Julian Hanak said: “Nearly one-tenth of the world’s population, around 840 million people, suffer from chronic kidney disease. For many of them, there are few options beyond dialysis and transplantation. Our novel treatment platform and deep understanding of kidney disease puts us in a position to stop, reverse and even cure kidney disease. The funds raised will allow us to bring our novel treatments to patients in the clinic.”
