Immusoft's 'Living Biofactory' Gets $15M to Fight Rare Disease

SAN FRANCISCO, CA – March 30, 2026 – Biotechnology firm Immusoft has received a major financial boost in its quest to treat a devastating rare disease, securing a $15 million grant from the California Institute for Regenerative Medicine (CIRM). The funding is set to accelerate the clinical development of ISP-001, a pioneering therapy for mucopolysaccharidosis type I (MPS I), a lethal genetic disorder that primarily affects children.

The grant underscores a significant vote of confidence in Immusoft’s novel approach, which transforms a patient’s own immune cells into miniature, long-term drug-producing factories inside their body. This new capital injection will expand the ongoing Phase 1/2 clinical trial, potentially extending the treatment to pediatric patients and moving a promising therapy closer to reality for families with few good options.

The Unrelenting Toll of MPS I

To understand the significance of the new funding, one must first grasp the cruel nature of mucopolysaccharidosis type I. The rare genetic condition, occurring in roughly 1 in 100,000 births, is caused by a deficiency of an essential enzyme called alpha-L-iduronidase (IDUA). Without this enzyme, sugar molecules known as glycosaminoglycans (GAGs) build up to toxic levels within cells, leading to progressive and catastrophic damage to the heart, lungs, bones, and brain.

For children with the most severe form, Hurler Syndrome, symptoms appear within the first year of life. If left untreated, they rarely survive past the age of ten. Current treatments, while life-extending, are arduous and have significant drawbacks.

Enzyme Replacement Therapy (ERT) requires weekly, lifelong intravenous infusions that consume hours at a time. While it can manage some symptoms, the therapy struggles to penetrate certain tissues and, crucially, does not cross the blood-brain barrier, leaving the progressive neurological damage of Hurler Syndrome unchecked. Hematopoietic Stem Cell Transplantation (HSCT) is the standard of care for severe cases but is a high-risk procedure. It requires harsh chemotherapy to prepare the body, carries risks of graft-rejection and infection, and is most effective only when performed in the first two years of life, before irreversible damage has occurred.

“There is no cure for MPS I, and there is a significant unmet need for therapies that can deliver meaningful functional improvements for patients,” said Sean Ainsworth, Chief Executive Officer of Immusoft. “ISP-001 has shown early signs of functional improvement and reductions in pain, highlighting its potential for long-term, continuous therapeutic protein delivery that may avoid many of the limitations of other approaches being developed.”

A 'Living Biofactory' Inside the Body

Immusoft’s ISP-001 represents a radical departure from conventional treatments. The therapy leverages the company's proprietary Immune System Programming (ISP™) platform to engineer a patient’s own B cells—a type of white blood cell responsible for producing antibodies.

The process begins by collecting a patient's B cells. Outside the body, these cells are genetically programmed using a non-viral method to produce and secrete the missing IDUA enzyme. These modified cells are then multiplied and infused back into the patient. The goal is for these engineered cells to take up long-term residence in the body, becoming “living biofactories” that continuously produce and release the therapeutic enzyme into the bloodstream, potentially for years from a single treatment.

This approach offers several potential advantages. It aims to provide stable, continuous enzyme levels, avoiding the peaks and troughs of weekly ERT infusions. Critically, it does so without the need for the intensive chemotherapy preconditioning required for stem cell transplants or the immunogenicity risks associated with viral vectors used in some gene therapies.

Early clinical data has been promising. The therapy has demonstrated a favorable safety profile, and in what the company calls a “watershed moment” for cell therapy, a patient was safely re-dosed, subsequently showing positive functional and quality-of-life improvements. A second patient, receiving a higher dose, has also shown encouraging early results.

California's Strategic Bet on a Biotech Future

The $15 million grant is more than just funding; it is a strategic investment by the state of California. CIRM was created by voters and entrusted with over $8.5 billion to de-risk and accelerate the development of regenerative medicines, bridging the so-called “valley of death” between laboratory discovery and clinical application.

This award comes from CIRM’s CLIN2 funding program, which targets clinical-stage therapies with the potential for transformative benefits. By backing Immusoft, the state agency is betting that this engineered B cell platform can provide a high-impact solution for a disease with a dire unmet need. This aligns with CIRM's strategic goals of advancing therapies for rare diseases and cementing California's status as a global hub for biotechnology innovation.

“Advancing innovative, high-impact therapies for patients with serious diseases such as MPS I is central to CIRM’s mission,” said Jonathan Thomas, PhD, JD, President and Chief Executive Officer of CIRM. “This trial brings hope to patients with MPS I who otherwise have no effective therapies.”

While Immusoft’s approach is groundbreaking, it is not the only one vying to change the future of MPS I treatment. The competitive landscape includes advanced gene therapies from companies like Orchard Therapeutics and REGENXBIO, which use viral vectors to deliver a corrected IDUA gene. Others, like JCR Pharmaceuticals, are developing next-generation enzyme replacement therapies designed to cross the blood-brain barrier. Immusoft’s ability to deliver therapy without viral vectors or preconditioning, combined with its demonstrated re-dosability, could provide a key competitive edge in a field racing toward a cure.

With Fast Track, Rare Pediatric Disease, and Orphan Drug designations already granted by the FDA, ISP-001 is on a clear regulatory path. This latest infusion of capital from CIRM will be critical in navigating the next stages of clinical trials, bringing a potential paradigm shift in treatment one step closer for the children and families battling MPS I.