Severe Combined Immunodeficiency
Severe Combined Immunodeficiency (SCID) is a rare disease which causes patients to practically have no immune system at all. That means that for these patients, even a common cold can be deadly. At one point, those living with SCID were forced to stay in complete isolation. That is where the term “bubble boy” comes from. Children were kept in a sterile chamber to reduce their risk of germ exposure.
Researchers at St. Jude Children’s Research Hospital have been working on developing a gene therapy which could serve as a potential cure for this condition. Their therapy has successfully treated eight patients and the hospital has just announced that they have licensed the therapy to Mustang Bio. The company plans to file for global approval of the treatment by the end of 2021.
Gene Therapy
Basically, gene therapy utilizes a virus to deliver a functioning copy of the defective gene to the patient. The healthy gene will then live and work in the body indefinitely. Gene therapy is being investigated as a one-time treatment for a variety of conditions including sickle cell anemia, spinal muscular atrophy, and hemophilia as well as SCID.
The recent success of the gene therapy treatment by St. Jude for SCID in eight patients is extremely exciting.
Where are these children now? They’ve been released from the hospital where they lived their entire infancy in isolation. Doctors consider them completely cured. With fully functioning immune systems they can now live their lives like normal- attend daycare, see other children, and live life more carefree. Researchers say their immune systems are functioning just like a normal, healthy child. All of the children have also made antibodies in response to the vaccines they’ve been given.
The results from this study at St. Jude will be published in the New England Journal of Medicine.
The results are particularly exciting because to date, none of the children in the trial have developed leukemia. In a previous study in Europe, 1/3 of participants developed the condition beginning one year after they received the therapy. Despite the therapies effectiveness in treating SCID, this is clearly a dangerous side effect.
Researchers in this new study believe the risk is minimal, but obviously follow-up for these patients is important.
Ja’Ceon Golden
Ja’Ceon was one of the eight boys treated and cured with this therapy. He was born in New Mexico in 2016 and his SCID diagnosis was discovered with newborn screening. His bone marrow cells were sent to St. Jude. There, a virus (containing the functioning gene Ja’Ceon was missing) was combined with the stem cells from his bone marrow. In the meantime, the child was given a low dose of chemotherapy. This assured there was room for the healthy cells.
Ja’Ceon was then given the gene therapy, a procedure that takes just minutes. After a few months of recovery, he was determined to have a fully functioning, healthy immune system.
In May of 2017 he was finally able to leave the hospital where he had lived since birth. Now, although he has faced some infections, he’s been able to fight the off like a normal child.
Ja’Ceon’s success story is a testament to the impact this therapy could have on children with SCID. The Chief Executive Officer of Mustang Bio is confident that they will receive FDA approval, pending results from a few more patients undergoing the treatment.
You can read more about this new gene therapy here.
