In a Major Breakthrough for Cell and Gene Therapy, Immusoft Has Re-dosed a Patient with ISP-001 in Its Lead Program for MPS I
The re-dose of ISP-001 has been well-tolerated, to date, and Immusoft continues to observe positive results
SAN FRANCISCO, Oct. 7, 2025 /PRNewswire/ — Immusoft of CA, a clinical stage, engineered B cell company, today announced a historic achievement: the safe and well-tolerated re-dosing of a patient with a gene modified therapeutic product candidate. The patient in Immusoft’s first-in-human clinical study has now received two doses – separated by 18 months1 – of ISP-001 to treat mucopolysaccharidosis type I (MPS I), with an excellent safety and tolerability profile, to date. Moreover, Immusoft continues to observe positive results in this ongoing clinical trial.
This is a momentous event for Immusoft and for the broader gene therapy community, which has long sought the ability to re-dose systemically to express therapeutic proteins at high levels. “The vast majority of gene therapies are not re-dosable with current technologies, for a variety of reasons, which is what initially drew my attention to Immusoft’s engineered B cell approach.” stated Sean Ainsworth, CEO of Immusoft. “There have long been questions about lifelong durability of one-and-done gene therapies and the ability to safely re-dose has been a much sought after feature in advanced therapeutics. In more recent times, we are seeing that it’s difficult for many of these approaches to be safely dosed a first time, let alone a second time.”