CAR-T therapy has been successful at treating lethal blood cancers, and new studies show that it may even fight against certain kinds of solid tumors. The treatment is a type of immunotherapy that utilizes a patient’s own cells to help the immune system see and fight cancer. Researchers hope that CAR-T therapy may in the future help to treat a wider variety of cancers.
CAR-T therapies were first approved in 2017 to treat certain kinds of leukemias and lymphomas. Clinicians modify the patient’s immune cells in the lab and then give them back to the patient through an IV, putting them directly into contact with the cancer in the blood. This approach has been successful at treating blood cancers, but has shown to be difficult when the cells must travel through the bloodstream to reach solid tumors in the lungs, breast, colon, or other organs.
Dr. Prasad Adusumilli from Memorial Sloan Kettering Cancer Center in New York says that “solid tumors are notorious for not letting the immune cells enter.” There is also a concern that the proteins found on solid tumor cells are also present on normal cells in lower levels. This means that the therapy targeting those cells could potentially damage normal cells as well.
But Adusumilli worked to create a new CAR-T therapy to try and mitigate these issues. He tested the therapy on 19 patients with mesothelioma and two patients with lung and breast cancer that spread to the chest lining. The research team injected the modified cells directly into the patient’s chest where the tumors resided. The researchers also created a genetic safety switch so that patients could be given medicine to get rid of the cells in case they were doing damage.
After receiving this therapy, one patient went on to have surgery and radiation therapy. Twenty months later, this patient has received no further treatment and is still doing well. 15 other patients who received this treatment became well enough to begin another immune-boosting drug. Researchers have followed 11 of those 15 patients long enough to report results. 2 of the patients saw signs of cancer disappear for a year, but one had an eventual relapse. 6 patients had tumor shrinkage, and 3 patients experienced cancer progression. None of the patients experienced severe side effects, but some did have temporary low blood counts and some fatigue.
Richard Carlstrand of Long Key Florida is one patient who tried the new therapy. He had mesothelioma, which is an aggressive cancer that affects the lining of the lungs. It’s been over a year since he had the therapy, and he still shows no signs of cancer. “I couldn’t be happier,” he said.
A larger study will be done to determine the safety and efficacy of this drug, with the help of grants from the federal government and other foundation. There is also a second study underway to test a different CAR-T therapy in patients with advanced sarcomas, cancers that occur in soft tissues or bones. Studies have shown promising results so far, and it’s the hope that CAR-T therapy will become a standard treatment for solid tumors in the future.