As its lead gene therapy flows toward the clinic, Purespring Therapeutics is uncorking new preclinical data showing the candidate reduced kidney scarring and fibrosis in mice and safely delivered a gene to pig kidneys.
The results were presented on Oct. 26 at the American Society of Nephrology Kidney Week 2024 in San Diego.
Purespring’s gene therapy, PS-002, uses a viral vector to target kidney cells—known as podocytes—to treat IgA nephropathy, a disease that causes pain, bloody urine and fatigue, and can lead to kidney failure. The condition’s symptoms can be managed with treatment, but currently no approved cure exists.
Purespring used PS-002 to deliver a gene to podocytes encoding a regulatory protein that controls the levels of protein fragments called complements within the kidney’s filtering structures. The complement system is part of the innate immune system, but can contribute to numerous diseases when it acts errantly, including kidney conditions.
In a mouse model of IgA nephropathy, mice given PS-002 had lower levels of complement deposited in their kidney cells and less protein in their urine, along with healthier kidney morphology, Purespring said in the release.
Three Gottingen minipigs given PS-002 showed stable expression of the therapeutic gene in their kidneys up to 56 days after dosing, according to the biotech. The swine showed no treatment-related side effects as a result of the therapy, the company added.
“Purespring’s gene therapy platform, exemplified by PS-002, demonstrates therapeutic genetic material can be delivered with high efficiency to podocytes, opening up a new and highly differentiated modality with the potential to treat a broad range of kidney diseases,” Purespring principal scientist Ambra Cappelletto, Ph.D., said in an Oct. 28 release.
London-based Purespring announced that it had bottled a $105 million series B earlier this month, with plans to use the funds for launching a phase 1/2 trial for PS-002.