A new type of cancer treatment that involves altering a person’s genes — and could save children’s lives — passed a major hurdle this week, when a U.S. Food and Drug Administration (FDA) panel recommended that the agency approve the therapy, The New York Times reported. But how does the treatment work?
The treatment is for an uncommon type of leukemia, called B-cell acute lymphoblastic leukemia, that affects mainly children and young adults, according to the Times. The success rate of the treatment that was seen in a recent clinical trial was “astonishing,” said Lee Greenberger, chief scientific officer of the Leukemia and Lymphoma Society (LLS). Greenberger was not involved directly in the research of the new therapy, but the LLS has contributed significant funding toward the work.
Leukemia is cancer of white blood cells, and it starts in the bone marrow, the soft material found in the center of bones that produces blood cells. [11 Surprising Facts About the Immune System]
Simply put, the new treatment works by rewiring a person’s own immune cells to fight cancer.
To do this, doctors first remove millions of the immune cells, called T cells, from a patient’s blood, Greenberger told Live Science. Normally, T cells help destroy infected or cancerous cells.
These T cells are sent to a lab to be purified, and then are genetically engineered, Greenberger said. Scientists mix the cells with a virus that works as “vector” to insert a bit of genetic material into the cells’ DNA. (Viruses commonly insert their DNA into living cells.) In this case, the vector that’s used is an inactive form of HIV. After 15 to 25 days — during which the cells have started to produce the new protein that is encoded by the DNA, as well as grow and multiply — the “gene-altered” T cells are infused back into the patient.
“It’s basically a one-time therapy,” Greenberger said.
The genetic material that the virus inserted into the T cells makes the…