Immune-based cancer treatments are surging forward as the Food and Drug Administration (FDA) on Wednesday approved the second of a new technology called CAR T, this time to treat diffuse large b-cell lymphoma, a type of non-Hodgkin lymphoma. In August, the agency approved the first CAR T cell therapy, a type of gene therapy to treat acute lymphoblastic leukemia in children.
CAR T cell therapy, which stands for chimeric antigen receptor T cell therapy, involves removing immune cells known as T cells, genetically engineering them to recognize proteins on cancer cells and target them for destruction, and infusing the modified immune cells back into the patient. The treatment works the same way that immune cells eliminate bacteria and viruses. It’s proving especially effective for blood cancers, since the immune system can ferret out an impressive number of cancer cells lurking anywhere in the blood and body.
“We think this therapy is here to stay. It’s very different from chemo,” says Dr. Frederick Locke, research director and clinical director of immune cell therapy at Moffitt Cancer Center in Tampa. “This is a living, breathing therapy that we are putting back into the patient that can persist, and continue to fight against the cancer. It’s pretty amazing.”
In the trial the FDA reviewed, submitted by Kite Pharma and Gilead Sciences, 101 people with one of three types of lymphoma were enrolled to receive the treatment, called Yescarta, at 22 hospitals. All of the people in the study had tried and failed to respond to existing treatments of chemotherapy and stem cell transplants; they had no additional therapies available to them. Overall, 54% of these end-stage patients saw their cancers shrink or stop growing after six months, and 80% were still alive.
“The results are exciting, and pretty much a game changer,” says Locke, who oversaw one of the study sites. “We know these patients might have a one in four chance of having any response to chemo, and a less than one in 10 chance of a complete response.”
Yescarta could be useful for the 3,500 people in the U.S. who are currently exhausting their options for treating their lymphomas. As with the first CAR T cell treatment approved, called Kymriah by Novartis, the therapy will only be available at 10 to 15 hospitals that have experience in managing the genetically modified cells and monitoring for the treatment’s side effects, which can be severe. During the trial for Yescarta, a patient died from a brain toxicity of the therapy. Because the treatment revs up the immune system, it can cause dangerous and potentially fatal swelling and inflammation. Doctors have learned to manage the complications, but it remains a risk of the CAR T cell approach, and one of the reasons it won’t be available at every cancer center at first. Because people who have not responded to other treatments for their cancer may have compromised health overall, determining who will benefit and who might be more susceptible to the side effects will be a decision that doctors with experience in transplants and cell treatments will be in the best position to make.
Locke says that treating the first signs of toxicity early also seems to reduce the severity of symptoms, and doctors will continue to investigate factors that can affect who might be more vulnerable to the side effects.
For now, the therapy could provide another option for patients with end-stage lymphomas. Physicians at Moffitt Cancer Center are already planning to expand the hospital’s resources in order to meet the anticipated demand.
The treatment is estimated to cost about $373,000. But experts note that if it is as powerful as the early results show, that high price tag could end up actually saving costs, compared to the multiple rounds of chemotherapy and transplants over a period of years that most people with lymphoma currently pay for.