According to the Associated Press, the treatment called CAR-T therapy enhances the cancer disease resistance of patients’ immune cells and can cost hundreds of thousands of dollars.

Studies have shown that CAR-T is effective against certain types of cancer. It also causes serious side effects. The US Food and Drug Administration approved the use of gene therapy to treat certain types of leukemia and lymphoma.

Medicare considered it for a few months before deciding on Wednesday. According to the Associated Press, the agency’s insurance policy can affect private insurance.