When it comes to the development of cancer treatments, the decades-long arc of progress is slow and incremental. Then something truly significant happens to change the course of the disease. What’s happening now appears to be one of those moments.
Latest development: A type of blood-cancer treatment that has already shown remarkable success in clinical trials is beginning to receive FDA approvals. Two of these treatments, for example, have recently been approved (see below).
With the new treatment, known as CAR T-cell therapy, blood is drawn from a patient to isolate his/her T-cells, the powerhouses of the body’s immune system. The T-cells are genetically altered and reprogrammed to recognize and kill tumor cells and then infused back into the patient.
The treatment has been called a “living drug” because it’s hoped that the enhanced T-cells will continue to multiply and remain active in the body, possibly providing lifelong protection against the cancer.
A GAME CHANGER
Researchers at universities and pharmaceutical companies have now developed CAR T-cell therapy for leukemia, multiple myeloma and lymphoma—blood cancers that account for about 10% of all cancer cases diagnosed in the US each year.
The hope is that similar treatments eventually will be used for tumors affecting the breast, lung, prostate and other parts of the body. Important: The treatment of “solid” tumors with this type of gene therapy still presents formidable obstacles that will have to be overcome.
CAR T-cell therapies have mainly been studied in patients with lymphoma or other blood cancers that didn’t respond well to standard treatments or that later recurred.
Example: Lymphoma patients are typically given several types and/or protocols of standard chemotherapy without a sure result. These patients are thought to be good candidates for CAR T-cell therapy—and the early results are promising. Studies show that up to 80% of such patients respond to CAR T-cell therapy, and about 30% to 40% of patients were still in remission after six months. In earlier studies, some patients have remained in remission for more than five years.
Important caveat: So far, hundreds of patients have been treated with CAR T-cell therapy. We’re seeing remarkable response rates, with many patients achieving a “complete” response—meaning that no cancer is detectable in the body with current methods. But the treatments are too new—and patients haven’t been followed for a long enough time—to say for sure that the treatments promise a cure.
HOW IT WORKS
Except for cases for which FDA–approved CAR T-cell therapy now is available (see below), adult patients who are eligible for this treatment receive it by participating in a clinical trial. They report to a laboratory or clinic, where they undergo a four-to-six-hour process to collect blood cells, which are then sent to a company that reengineers the patient’s T-cells, giving them the ability to recognize a protein (for example, CD19) on the surface of blood–cancer cells. The engineering process takes two to four weeks.
The patients are given several days of routine chemotherapy. After that, the engineered T-cells are given back to the patient via infusion. This treatment, which takes about 15 minutes, usually is administered just once, though some studies allow a second infusion if there is a partial response or relapse. The cell infusion and period of observation thereafter are typically done on an inpatient basis.
The reengineered cells circulate throughout the body and quickly begin to multiply and attack the tumor cells. Even though it’s hoped that the reengineered cells will stay active in the body indefinitely, it’s too early to know if this will happen. The cells might last for six months, 12 months…or forever.
With the treatment beginning to get FDA approval, it is expected to be very expensive—possibly costing hundreds of thousands of dollars. At this point, it’s unclear the extent to which insurance will cover the cost.
For now, the CAR T-cell treatments are somewhat risky. The genetically altered T-cells, when activated by cancer cells, can trigger a condition known as cytokine release syndrome. Many patients experience intense flulike symptoms, including a high fever, aches and fatigue. About 10% to 15% will get sick enough that they require ICU-level care, but these side effects can be treated with steroids and other drugs. Mild-to-severe confusion may develop in up to 30% of patients. While this too is reversible, there have been cases of fatal brain swelling.
The cardiac stress and respiratory distress due to the “inflammatory cascade” that is triggered by the treatment also can be life-threatening. The risks will undoubtedly decline as doctors gain more experience with the therapy.
HOW TO ACCESS THIS THERAPY…
Latest development: Based on the results of trials of CAR T-cells in children and young adults with acute lymphoblastic leukemia, in August 2017, the FDA approved a CD19-targeted CAR T-cell therapy called tisagenlecleucel (Kymriah). In October 2017, a second CAR T-cell therapy, axicabtagene ciloleucel (Yescarta), was approved for patients with large B-cell lymphomas who have not responded to other treatments.
For patients with lymphoma, leukemia or multiple myeloma for whom an FDA-approved CAR T-cell therapy is not available, a clinical trial may be an option. If your doctor believes that you’re a candidate for CAR T-cell therapy, discuss whether it makes sense for you to participate in an ongoing study. Your oncologist can advise you about clinical trials in your area. If accepted into the trial, the CAR T-cell therapy is covered but supportive care is billed to insurance.