The highly scientific approach to attacking these cancer cells was successful in a study where 27 of 29 patients with an advanced type leukemia were in remission after the experimental treatment.
Now FDA approved, CAR T-cell therapy — commonly known as CAR T — promises to significantly improve outcomes. Cancer centers like the Northwell Health Cancer Institute are building programs to administer the treatment.
Here are five things you need to know.
1. How does CAR T work?
CAR T stands for chimeric antigen receptor T-cell therapy. The treatment entails scientists removing T cells from a patient’s blood, adding proteins to them and infusing the engineered cells (and blood) back into the body. The new CAR T cells then attack the cancer cells.
2. A five-step process
- Collecting cells via leukapheresis: a noninvasive removal of blood to collect the T cells.
- Boosting the T cells: Scientists insert chimeric antigen receptor (CAR) — an antibody-like protein — on the surface of the T cells.
- Increasing and harvesting the cells: The cells are multiplied into the millions and frozen.
- Infusion: Patients undergo chemotherapy while waiting for the boosted CAR T cells to return. The cells continue to expand as they re-enter a person’s body.
- Monitoring and treatment: Patients remain in the hospital two or three weeks after infusion. A serious and common side-effect called cytokine release syndrome can include fever, nausea, headache, rash, rapid heartbeat, low blood pressure and trouble breathing. For this reason, CAR T treatment requires a higher level of monitoring in an inpatient setting.
3. Approved therapies
There are currently three CAR T-cell therapies approved in the US — one for advanced or recurrent acute lymphoblastic leukemia (ALL) in children and young adults, and the others for certain types of advanced or recurrent large B-cell lymphoma (one of several types of non-Hodgkin’s lymphoma). While the FDA only approved CAR T treatments in August 2017, it is still unclear whether the treatment is considered a long-term cure. Researchers are currently studying risks for recurrence, as well as side effects of the treatment.
You can’t put a price tag on cancer remission. But initial costs of the first CAR T-cell therapies, Novartis’ tisagenlecleucel and Kite Pharma’s axicabtagene ciloleucel, were $475,000 and $373,000 respectively. According to an April JAMA Oncology report, those amounts don’t include costs associated with leukapheresis, lymphodepletion therapy and treatment for cytokine release syndrome. So, depending on the severity of cytokine release syndrome, tisagenlecleucel could range from $478,777-$531,823. The mean expected cost for axicabtagene ciloleucel is $402,647.
5. What's next?
The biggest downfall to CAR T-cell therapy has been cytokine release syndrome. The potentially life-threatening condition affects a third of patients receiving CAR T. In late May, researchers in the US and Italy identified a way to avoid the side effect for leukemia patients who undergo CAR T. One mouse-model study used drugs to block a key molecule in the syndrome. The second study, also a mouse model, genetically modified the T cells to prevent the side effect. This could lead to safer and more advanced CAR T therapies.
Ruthee Lu Bayer, MD, is director of Northwell Health’s Cancer Institute’s Stem Cell Transplantation Program. She is also a oncologist at the Monter Cancer Center.