On Wednesday — for only the second time — the United States' Food and Drug Administration approved a cutting-edge therapy that genetically modifies a patient's blood cells in order to attack cancer. This time the therapy, known as CAR T-cell therapy, is designed to treat aggressive non-Hodgkin lymphoma.
T-cells. Image: Memorial Sloan Kettering Cancer Center
In August, the FDA approved the first CAR T-cell therapy, for a drug called Kymriah designed for children and young adults whose leukemia doesn't respond to standard treatments. The FDA's approval of Yescarta, manufactured by Kite Pharma, comes just a few months after its first approval — an indication of just how quickly the field of immunotherapy is moving. Several other companies also have CAR-T therapies in the works.
"Today, marks another milestone in the development of a whole new scientific paradigm for the treatment of serious diseases," FDA Commissioner Scott Gottlieb said in a statement, adding that the approval demonstrates "the continued momentum of this promising new area of medicine."
CAR-T therapy works by reprogramming a patient's cells in order to attack their cancer from the inside. Doctors harvest a patient's T-cells (a type of white blood cell) and then, in the lab, genetically modify them to turn them into tumour assassins. The cells are then placed back into the body where they zero in on and destroy cancerous cells. The whole process takes about 17 days. (The FDA has called it "gene therapy," though experts quibble over whether that term applies.)
Yescarta is designed for adults with certain types of large B-cell lymphoma for whom at least two other kinds of treatment have not proved effective or resulted in relapse. There are about 7,500 patients a year in the US who would be candidates for the drug. The treatment is intended to be administered once with a price tag of $US373,000 ($475,292), less than Kymriah, which is expected to cost $US475,000 ($605,264). Kite Pharma, which developed Yescarta, was recently bought by Gilead Sciences for $US11.9 ($15) billion just ahead of its drug's expected FDA approval.
In a key trial of 100 patients cited by the FDA, Yescarta resulted in complete remission for 51 per cent of patients.
But Yescarta is not without risk, and the FDA said it will carry a warning for neurologic toxicities and cytokine release syndrome, a condition in which the body reacts to the CAR-T cells with high fever and other flu-like symptoms.
The drug was approved along with a risk evaluation strategy that requires hospitals and clinics that prescribe the drug to be specially certified and trained. The FDA is also requiring Gilead to conduct a follow-up study of the drug's long-term effects.