An experimental therapy that trains the body's immune system to fight leukemia may hold the key to better and more effective ways of combating cancer in the future.
In the study "Efficacy and Toxicity Management of 19-28z CAR T Cell Therapy in B Cell Acute Lymphoblastic Leukemia" published in the journal Science Translational Medicine Feb. 19, researchers involved 16 patients with a blood cancer called B-cell acute lymphoblastic leukemia (ALL), a condition that affects a type of white blood cell that manufactures antibodies.
The patients then underwent a treatment called T-cell therapy, wherein doctors harvested "hunter cells" known as T-cells from their blood. The T-cells were genetically engineered in the laboratory so they could recognize a protein called CD19 found in the cancer cells and eventually attack ALL cells. The modified T-cells were then infused back into the patients' body after a standard chemotherapy.
"Basically, what we do is re-educate the T cell in the laboratory with gene therapy to recognize and now kill tumor cells," said study author Renier Brentjens, director of cellular therapeutics at Memorial Sloan Kettering Cancer Center in New York.
Although T-cell therapy isn't approved by the U.S. Food and Drug Administration (FDA) yet and is only available in research settings, Brentjens and colleagues' trial had positive results as 14 of the 16 subjects went into remission. Seven of the patients were even able to have a bone marrow transplant.
"This is really one of the watershed moments where we find that we actually can modulate the immune system to recognize cancer," Brentjens said. "When we infused these cells into the patients, the patients became sick as if they had a bad infection. But once the cancer cells go away as they're being killed off by the immune system, that immune response goes away as well."
While results of the t-cell therapy trial with ALL patients were encouraging, it isn't clear yet if the therapy can be used for patients suffering from other types of cancer. The researchers, however, said that this will also be explored. "The expansion to other kinds of cancers is next on the to-do list," said Brentjens.
The treatment also had side effects such as blood pressure drops, persistent fever and difficulty breathing, known as cytokine release syndrome (CRS), which was experienced by seven of the 16 patients in the study. The cost of the therapy is also prohibitive at around $100,000 per patient although experts believe the cost may still go down once pharmaceutical companies step in and the treatment becomes more widespread.
