B cells are a type of naturally occurring white blood cell that help protect the body from illness. They are part of the body’s immune system.

When B cells become activated, some can turn into plasma cells, which act like tiny protein factories, or “biofactories”—as we call them—inside the body. Plasma cells can continuously make and release proteins over time.

Immusoft is using the natural abilities of B cells to develop novel therapies that help produce important proteins the body may be missing due to disease. 

Both engineered B cell therapies and stem cell therapies are cell-based therapies, often using a patient’s own cells to be modified to address disease. The cells are collected, modified in a lab to address a specific need for patients with a relevant disease, and then returned to the body.

One important difference is how patients prepare for treatment.

Engineered stem cell therapies require chemotherapy to condition the body to receive the modified stem cells and help the new cells take hold in the body. This process can be difficult for patients and families, often resulting in serious side effects and lengthy hospital stays.
Immusoft’s engineered B cell approach is designed to work without chemotherapy conditioning.

As such, it offers the possibility of repeat dosing, which is not typical with engineered stem cell therapies due to the severely toxic chemotherapy required.

Both engineered B cells and viral gene therapy involve modifying a patient’s cells. However, viral gene therapy modifies the patient’s cells inside the body using what is referred to as a virus “vector”.

In order for this to work, the patient must first undergo a chemical immunosuppression regimen, which can have serious side effects and safety concerns. Additionally, viral gene therapies in development and on the market have recently resulted in considerable safety concerns, including death.

Immusoft’s approach using modified B cells is designed to work without immunosuppression and also offers the possibility of repeat dosing, which is not currently possible with most viral gene therapies.

Immusoft is studying ISP-001, our lead B cell candidate, in clinical trials to better understand how quickly this investigational therapy and future B cell therapies may begin working and how long the effects may last.

The goal of Immusoft’s engineered B cell approach is to provide sustained delivery of therapeutic proteins over extended periods of time using the patient’s own cells.

Early clinical data have shown encouraging signs of biomarker and functional improvement out to one year, but more research is still needed.

MPS I (Mucopolysaccharidosis type I) is a rare genetic disease that people are born with. It happens when the body cannot make enough of an enzyme called IDUA (alpha-L-iduronidase).

Without enough IDUA, certain long-chain sugar molecules called GAGs (glycosaminoglycans) build up inside cells throughout the body. Over time, this buildup can damage organs, bones, joints, and other tissues.

MPS I can lead to serious health problems that affect movement, breathing, heart health, growth, and daily life. There is currently no cure.

IDUA (alpha-L-iduronidase) is an enzyme that helps the body break down and clear materials called glycosaminoglycans (GAGs), which can be toxic, in excess.

In people with MPS I, the body does not make enough working IDUA. Without it, GAGs build up over time and cause damage in many parts of the body, and can even result in early death.

Current and investigational treatments for MPS I are designed to help restore IDUA levels in the body.

GAGs are natural sugar molecules made by the body. Normally, the body breaks down and removes excess GAGs using enzymes like IDUA.

Due to a deficiency in the IDUA enzyme, GAGs cannot be broken down properly, leading to a severe buildup inside cells and tissues throughout the body, contributing to the symptoms of MPS I.

Lowering GAG levels is one way doctors and researchers measure how well a treatment may be working, but it is only one measure of the impact of a disease on patients. Researchers also look at symptoms, functional outcomes, quality of life, etc. to understand the potential impact of a treatment. 

You are not alone. There are organizations dedicated to supporting MPS families with information, community, and resources.

MPS Society
International MPS Network
NORD
The Ryan Foundation
The EveryLife Foundation for Rare Diseases

ISP-001 is Immusoft’s lead investigational engineered B cell therapy, for MPS I.

The therapy uses a patient’s own B cells, which are modified in a lab to produce IDUA, the enzyme missing in people with MPS I. The cells are then returned to the patient’s body.

Once back in the body, the engineered cells are designed to continuously produce therapeutic levels of IDUA over time.

Immusoft’s goal is to reduce treatment burden while delivering meaningful functional improvement for people living with MPS I.

ISP-001 is currently being studied in a Phase 1/2 clinical trial and has received Orphan Drug, Rare Pediatric Disease, and Fast Track designations from the U.S. Food and Drug Administration (FDA).

ISP-001 is an investigational therapy and has not been approved by the FDA or any other regulatory agency.

It is currently being studied in a Phase 1/2 clinical trial for people with MPS I.

At this time, ISP-001 is only available through participation in the clinical trial for patients who qualify. For more information about the trial, visit clinicaltrials.gov (NCT05682144) or the research study website.

Early clinical data from Immusoft’s ongoing Phase 1/2 clinical trial have shown favorable safety and tolerability results for ISP-001.

Immusoft has also reported reductions in GAGs, functional improvements, and improvement in quality-of-life outcomes in some patients. We have also demonstrated the ability to safely re-dose a patient.

Researchers will continue to evaluate ISP-001 to better understand its long-term safety and potential benefits.

Enzyme replacement therapy (ERT) is a standard treatment for MPS I that provides patients with regular infusions of the missing IDUA enzyme.

These infusions are usually weekly and can take several hours, which may place a significant burden on patients and caregivers.

ISP-001 is designed to work differently. Instead of repeatedly infusing enzyme into the body, the therapy uses engineered B cells designed to continuously produce IDUA over time.

Immusoft believes sustained delivery of IDUA through a modified B cell therapy may help provide more consistent enzyme levels and deliver meaningful functional improvement, while reducing treatment burden for families.