Immunotherapy Gives Hope to Multiple Myeloma Patients
For most of us, a common cold or a stomach bug is a nuisance, but usually in a matter of days the body’s immune system will fight off the invading disease-causing agents and we’ll get back to normal. In more serious situations, the immune system even defeats pneumonia, endocarditis, and other severe health threats.
But that’s not the case for the 20,000 to 30,000 Americans who are diagnosed with multiple myeloma each year. Multiple myeloma is a form of cancer that affects plasma cells, the white blood cells in the bone marrow that produce antibodies to fight disease and infection.
Current treatment options include chemotherapy, radiation therapy, specialized drugs, and stem cell transplants. Despite advances in these approaches, the average American will succumb to multiple myeloma about seven to 10 years after being diagnosed with the disease.
“While we can treat the disease well initially, almost every single patient with multiple myeloma relapses, and every time the disease comes back, it becomes more resistant to therapies, making it even harder to treat,” says Michaela Liedtke, MD, associate professor of hematology.
A novel treatment using CAR-T cells is showing promise for treating multiple myeloma. Understanding the treatmet requires a short course in cell therapy (see sidebar).
Liedtke explains that the treatment uses the patient’s own T cells, which reside in the body after eradicating the cancer.
Her expertise in CAR-T cells derives from her connection with Crystal Mackall, MD, Ernest and Amelia Gallo Family Professor of Pediatrics and Internal Medicine, and founder of the Stanford Center for Cancer Cell Therapy.
Liedtke’s research on the subject was part of a study published in the May 2, 2019 issue of The New England Journal of Medicine.
“With this new CAR-T cell technology, known as BB 2121, ultimately the hope is that it will cure the disease and make it go away forever,” Liedtke proclaims.
“If any other cancer cells should develop in the future—if a relapse should ever occur—then the CAR-T cells should be ready to address that relapse or alternatively additional CAR-T cells could be infused. That’s the theoretical context,” she says.
In fact, CAR-T cell technology has proven to be effective in treating acute lymphoblastic leukemia (ALL), especially in children.
“There are studies using similar CAR-T cells showing that half to two-thirds of children with relapsed ALL, another hematological cancer, can be cured of their disease,” she says.
What Are CAR-T Cells?
T cells, part of the immune system that defends the body against infections, can become compromised when a patient develops a malignancy. One way to overcome that is to remove the T cells from the patient’s body and “re-educate” them in the laboratory. That is, each T cell is given a chimeric antigen receptor (CAR), which is why these engineered biological units are known as CAR-T cells.
After the T cells have been converted to CAR-T cells, they are reintroduced into the patient’s bloodstream and circulate in the body. The CAR-T cells are able to recognize, hunt for, and bind to certain characteristics on the surface of cancer cells before destroying them.
The CAR-T cells become very prolific and recreate themselves in great numbers. These expanded numbers of CAR-T cells circulate throughout the body and continue to hunt for myeloma cells until all the malignant cells are destroyed.