Gene therapy could be a cure for "bubble boy disease"

They are born without a germ control system, each infection posing a threat to their life. At present, eight babies with "bubble boy disease" have been infected with gene therapy based on one of the worst enemies of the immune system – HIV, the virus that causes AIDS.

A study published on Wednesday details how scientists turned this enemy virus into a savior, modifying it so that it could not cause the disease, and then using it to deliver a gene that was lacking to boys.

"This therapy has cured patients," but it will take longer to see if it is a permanent fix, said Dr. Ewelina Mamcarz, one of the leaders of studying at the St. Jude Children's Research Hospital in Memphis.

Omarion Jordan, who will be 1 year later this month, followed treatment in December to treat severe combined immunodeficiency syndrome, or SCID.

"For a long time, we did not know what was wrong with him, he just kept catching these infections," said his mother, Kristin Simpson. To learn that he had SCID "was just heartbreaking … I did not know what was going to happen to him."

Omarion now has a normal immune system. "He's like a normal, healthy baby," Simpson said. "I think it's amazing."

The results of the study were published by the New England Journal of Medicine. The treatment was developed by a recently deceased St. Jude doctor, Brian Sorrentino.

DICS is caused by a genetic flaw that prevents the bone marrow from producing effective versions of the immune system's blood cells. It affects 1 newborn out of 200,000, almost exclusively men. Without treatment, it often kills in the first two years of life.

"A simple infection like colds could be fatal," said Mamcarz.

The surname "bubble boy disease" comes from a famous case of the 1970s – a Texas boy who lived 12 years in a protective plastic bubble to isolate sprouts. A bone marrow transplant from a genetically matched sibling can cure SCID, but most people do not have a suitable donor. Grafts are also medically risky – the Texan boy died after a death.

Doctors think that gene therapy could be a solution. It involves taking a portion of a patient's blood cells, using the modified HIV to insert the missing gene and returning the cells intravenously. Before recovering their cells, patients receive a drug that allows them to destroy part of their bone marrow so that the modified cells have more room to grow.

When doctors tried it for the first time 20 years ago, the treatment had unexpected effects on other genes and some patients subsequently developed leukemia. The new therapy has guarantees to reduce this risk.

A small study on older children suggested that it was safe. The new study tested it on infants and the doctors reported that the first eight who had been treated at St. Jude and San Francisco Benioff Hospital for UCSF children.

Within a few months, normal levels of healthy immune cells developed in seven boys. The eighth required a second dose of gene therapy, but now everything is fine too. Six to 24 months after treatment, the eight cells make all types of cells needed to fight infections and some have received vaccines that enhance their immunity against the disease.

No serious or lasting side effects have occurred.

Omarion is the 10th boy treated in the study, which is underway. It is sponsored by the Syrian Lebanese-Syrian American Association, the California Institute of Regenerative Medicine, the Assisi Foundation of Memphis and the Federal Government.

"So far, it looks good," but patients will need to be studied to see if the results will be sustainable, said Dr. Anthony Fauci, director of the National Institute of Allergy and Disease. infectious diseases, which contributed to the development of the treatment. "For me, that sounds promising."

The rights have been licensed by St. Jude to Mustang Bio. The doctors say they have no estimate of the potential cost of this treatment.

A similar technique exploiting a modified version of HIV is also being studied as a possible cure for sickle cell disease, Reports CBS News Chief Medical Correspondent, Dr. Jon LaPook. As part of a clinical trial at the National Institutes of Health, nine adults with sickle cell anemia have undergone gene therapy. Until now, all respond well.