Immusoft’s B Cell Gene Therapy Gets FDA Nod to Enter Clinical Trials

The biotechnology company Immusoft recently announced that the US Food and Drug Administration (FDA) has agreed to let it move forward with the first human study of a novel gene therapy using genetically engineered B cells instead of T cells. 

The company plans to harness B cells to treat a rare inherited disease called MPS-1. If the clinical trials produce pleasing results, it might become the first-in-class technology and a pioneering new approach to treating genetic diseases.

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Tackling Incurable Childhood Genetic Diseases

Mucopolysaccharidosis type I (MPS I) is a rare, lethal childhood genetic disease that affects the body’s ability to produce alpha-L-iduronidase (IDUA). IDUA is an essential enzyme that helps to break down long-chain sugars inside cells. 

The failure to break down sugars results in accumulation in the cells and eventually causes progressive damage to tissues and organs, including the brain. In severe situations, children affected rarely lived more than ten years after diagnosis. There are currently no curative interventions for MPS I; thus, additional therapies are of utmost need.

B cells are the immune system cells that act as factories to make antibodies and are highly effective at churning out as many as 10,000 a second. Moreover, B cells can persist for years inside bone marrow post-infection. Hence, the company aimed at the ability of B cells to manufacture proteins. However, in this case, the company planned to engineer B cells to produce missing enzymes instead of antibodies.

Manufacturing Proteins Without Generating Immune Responses

The main advantage of using blood-system cells to add new genes to a person’s body is that they can be removed from a patient, engineered in the lab, and then returned to the same person through an IV drip without stimulating an immune response as all the cells come from the patient.

Among the 15 gene therapies approved by regulators in the US or Europe, more than half involve adding gene cargo either to bone marrow stem cells or to white blood cells called T lymphocytes. According to the National Cancer Institute, six approved gene-therapy treatments for blood cancers in the U.S. involve engineering T cells, meaning genetically engineered B cells have never been tested in a human yet. 

B cell engineering is not as easy as others; thus, the company must find reliable ways to add genes to B cells. Instead of using viruses or gene editing to make genetic changes, the company now employs a transposon, a molecule that likes to cut and paste DNA segments. There is also a risk to launching the trial as the added DNA may end up near cancer-promoting genes and can sometimes turn them on. 

If the treatment proves successful, the researchers hope to try the same strategy on other diseases involving free-floating proteins in the blood, like producing clotting factors missing in hemophilia patients.

Author

Nai Ye Yeat