The Food and Drug Administration on Wednesday approved a ground-breaking gene therapy treatment in which a patient's blood cells are genetically engineered to attack and kill cancer cells.
Johns Hopkins Hospital will be one of 32 hospitals whose doctors will be specially trained to administer the procedure, an official with the hospital said.
The treatment was approved for children and young adults up to age 25 who suffer from acute lymphoblastic leukemia and for whom the standard treatment is ineffective, which the FDA said is about 15 percent to 20 percent of patients.
The disease, the most common childhood cancer in the United States, is a cancer of the bone marrow and blood that progresses quickly. About 3,100 people ages 20 and under are diagnosed with the disease each year, according to The National Cancer Institute.
"This is a brand new way of treating cancer," said Dr. Stephan Grupp of Children's Hospital of Philadelphia, who treated the first child with the CAR-T cell therapy — a girl who'd been near death but has now been cancer-free for more than five years. "That's enormously exciting."
The University of Maryland Medical Center is not one of the designated hospitals, but officials there said they are interested in making the therapy available to pediatric patients in the future.
Researchers at the university's Marlene and Stewart Greenebaum Comprehensive Cancer Center are running a clinical trial looking at the CAR-T treatment on adults with leukemia. They expected the FDA decision meant the agency would eventually approve gene therapy for other disorders.
"It is a whole different class of treatment and it can work extremely well in patients who have no other treatment options," said Dr. Maria Baer, who heads the hematologic malignancies program at the Greenebaum cancer center. "When it works, it works amazingly well."
Other researchers at the University of Maryland School of Medicine have also studied gene therapy to treat cancer. Earlier this year, a cancer treatment startup out of the medical school was acquired by Lentigen Technology, a life sciences company in Gaithersburg. The startup, called Living Pharma, is developing a cancer treatment that uses a patient's own T-cells to target tumors.
"Even though it is a niche therapy right now, these patients are children with a horrible disease and they are being cured," said Dr. Elizabeth M. Jaffee, president-elect of the American Association for Cancer Research and deputy director of the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins Hospital.
The CAR-T cell treatment, developed by Novartis Pharmaceuticals and the University of Pennsylvania, is the first type of gene therapy approved to treat cancer in the United States. It is one in a powerful but expensive wave of custom-made "living drugs" being tested against blood cancers and also some tumors.
Patients are given Kymria, a customized treatment created using an individual patient's own lymphocytes, or T-cells. The T-cells have been harvested and modified with a new gene. The new gene contains a protein that directs the T-cells to target and kill leukemia cells that have a specific antigen on the surface.
It's a completely different way to harness the immune system from the popular immunotherapy drugs called "checkpoint inhibitors," which treat a variety of cancers by helping the body's natural T cells better spot tumors. CAR-T cell therapy gives patients stronger T cells to do that job.
The FDA called the approval historic.
"We're entering a new frontier in medical innovation with the ability to reprogram a patient's own cells to attack a deadly cancer," FDA Commissioner Scott Gottlieb said.
This first use of CAR-T therapy approved by the FDA is aimed at patients who are desperately ill.
In a multi-site study of 63 advanced patients using the new therapy, 83 percent went into remission. But it's not clear how long that benefit lasts. Some patients relapsed months later. The others still are being tracked to see how they fare over the long run.
Still, "a far higher percentage of patients go into remission with this therapy than anything else we've seen to date with relapsed leukemia," said Dr. Ted Laetsch of the University of Texas Southwestern Medical Center, one of the study sites. "I wouldn't say we know for sure how many will be cured yet by this therapy. There certainly is a hope" that some will be.
The FDA warned that the treatment causes harsh and even life-threatening side effects. An immune overreaction called "cytokine release syndrome" can trigger high fevers, plummeting blood pressure and in severe cases organ damage. Special care is required to tamp down those symptoms without blocking the cancer attack.
Also Wednesday, the FDA designated a treatment for those side effects.
"This is remarkable technology," said Dr. Mikkael Sekeres of the American Society of Hematology. But "it isn't a panacea."
Sekeres, who directs the Cleveland Clinic's leukemia program, wasn't involved with the CAR-T testing.
Sometimes leukemia can develop resistance, he said, and sometimes patients worsen while waiting for their new cells.
"Unfortunately," he said, "leukemia grows so rapidly that it can evade even the smartest of our technologies."
For some patients, Grupp said, the CAR-T therapy might replace bone marrow transplants, which can cost more than half a million dollars.
Novartis said it would charge $475,000 for the CAR-T treatment, made from scratch for every patient. The company said there would be no charge if the patient didn't show a response within a month.
Grupp led the Novartis study.
"I don't want to be an apologist for high drug prices in the U.S.," he said. But if CAR-T is the last treatment they need, "that's a really significant one-time investment in their wellness, especially in kids who have a whole lifetime ahead of them."
While this first use of CAR-T therapy is aimed at only a few hundred U.S. patients a year, it's being tested as a treatment for thousands more. Kite Pharma's similar CAR-T brand, developed by the National Cancer Institute, is expected to win approval later this year to treat aggressive lymphoma, and Juno Therapeutics and other companies are studying their own versions against blood cancers, including multiple myeloma.
Scientists around the country are trying to make CAR-T therapies that could fight more common solid tumors such as brain, breast or pancreatic cancers — a more difficult next step.
The Associated Press contributed to this article.