The U.S. Food and Drug Administration last week approved a drug that genetically modifies a patient's immune cells to attack cancer cells. Washington University's Siteman Cancer Center at Barnes-Jewish Hospital is among the first medical centers to offer the treatment, which is aimed at helping those with non-Hodgkin's lymphoma and some types of blood cancers.
Yescarta, manufactured by California-based Kite Pharmaceuticals, is part of a new wave of drugs that use the immune system to fight cancer, also known as immunotherapy.
A doctor extracts T-cells, or white blood cells, from the patient's body and genetically alters them into chimeric antigen receptors. "CAR-T" cells can recognize, bind to and destroy cancer cells when they are infused back into the patient's body. The process generally takes about a few weeks.
Another way to think about it is to imagine that the cancer patient's body is like a battlefield and the white blood cells are weak soldiers, said Armin Ghobadi, a Washington University oncologist at the Siteman Cancer Center.
"You basically take them out and train them and give them the strongest weapon that is out there and put them back in the battlefield and they are extremely effective at killing the target," Ghobadi said.
The drug may be effective for patients who have been unresponsive to chemotherapy or bone marrow transplantation, the standard treatments for non-Hodgkin's lymphoma. In a recent trial that included more than 100 patients with a type of non-Hodgkin's lymphoma, Yescarta showed a complete remission rate of 51 percent after treatment.
While the drug demonstrates a stronger response rate than usual treatments, it also can cause some severe side effects. Patients treated with Yescarta run the risk of getting cytokine release syndrome, which can produce flu-like symptoms due to inflammation of the immune system. Patients may also develop neurological toxicity, which can make them unable to talk. In the worst case scenario, the brain could swell and the patient could die. These conditions can be mitigated by offering additional treatments, but the severity is why the drug is not offered everywhere, said Ghobadi.
Also, Yescarta is expensive. One dose of genetically altered white blood cells costs $373,000.
Like other immunotherapy drugs, doctors don't know yet if most patients treated with Yescarta will stay in remission for the rest of their lives. But Ghobadi said he looks forward to seeing more immunotherapy drugs become available to cancer patients.
"This is really a humongous step forward," Ghobadi said. "It's opening up the door for a new wave of treatments that cure not only lymphoma but other cancers too. It will dramatically revolutionize the way we treat cancer."
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