Purespring raises $105m for Phase I/II IgAN gene therapy trial

Purespring Therapeutics has garnered substantial financial support, securing £80 million ($105 million) to initiate a Phase I/II clinical trial for its innovative adeno-associated viral (AAV) gene therapy aimed at treating kidney disease. The London-based biotechnology company plans to use this funding to advance its leading candidate, PS-002, in the treatment of IgA nephropathy (IgAN). This disease is an autoimmune condition characterized by an accumulation of immunoglobulin A (IgA) protein in the kidneys, leading to inflammation and potentially progressing to end-stage renal disease.

PS-002, Purespring's experimental AAV gene therapy, focuses on targeting podocytes, specialized cells vital for maintaining proper kidney function. In cases of IgAN, these podocytes are damaged by immune complexes, resulting in protein leakage and kidney dysfunction. Purespring's research portfolio also includes other gene therapy programs, such as PS-001 for nephrotic syndrome and another for an unspecified glomerular kidney disease.

In May 2024, Purespring presented preclinical data for its PS-001 therapy at the European Renal Association (ERA) Congress. The findings demonstrated that transgenes could be effectively directed to podocytes to replace defective genes or employ the podocyte as a protein factory to influence kidney biology beneficially.

The recent Series B funding round was led by Sofinnova Partners, with contributions from Gilde Healthcare, Forbion, British Patient Capital, and founding investor Syncona. Purespring was originally launched by Syncona in 2021, starting with $45 million in Series A funding. The biotech company utilizes a platform known as FunSel, which acts as a 'gene search engine', selecting the most effective treatments for diseases from a vast library of AAV vectors without focusing on specific genes or mechanisms.

The field of IgA nephropathy has seen significant interest and activity in recent years, particularly in terms of mergers and acquisitions. In August 2023, pharmaceutical giant Novartis acquired Chinook Therapeutics for $3.2 billion, gaining access to two drugs, atrasentan and zigakibart. Both drugs are being evaluated in Phase III clinical trials for IgAN. Additionally, Vertex Pharmaceuticals and Biogen have forged deals with Alpine Immune Sciences and Human Immunology Biosciences, respectively. These agreements, each valued at over $1 billion, have provided the companies with assets aimed at treating IgAN.

Julian Hanak, CEO of Purespring, emphasized the urgency and significance of their work in the announcement accompanying the funding. He highlighted that nearly one-tenth of the global population, approximately 840 million people, suffer from chronic kidney disease, with limited treatment options beyond dialysis and transplantation. Hanak expressed confidence in Purespring's novel treatment platform and deep understanding of kidney disease, believing it positions the company to potentially stop, reverse, or even cure kidney disease. The funds raised will enable Purespring to bring its pioneering treatments to patients in clinical settings.

Purespring's ambitious efforts and innovative approaches underscore the growing momentum in the field of gene therapy for kidney disease, offering hope for more effective treatments and better patient outcomes in the future.