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A Therapy For Leukemia That Turns The Human Body Into A ‘Living Drug’ Awaits FDA Approval


A Food and Drug Administration advisory panel ushered in a new era for cancer treatment last week. The panel unanimously recommended the approval of the first treatment to fight acute lymphoblastic leukemia, a common blood cancer in children – with a patient’s own cells.

For the past few years, researchers from around the world have been running clinical trials, where they genetically alter people’s T-cells, their immune cells, to attack and shut down leukemia in the body. UT Southwestern Medical Center was one of 13 research sites in the U.S. – in fact, one of the biggest.

Dr. Theodore Laetsch is a pediatric oncologist at UT Southwestern Medical Center and Children’s Health in Dallas. He was also one of the study’s lead investigators. Laetsch says this first-ever gene cancer therapy could be formally approved as early as this year.

Interview highlights: Dr. Theodore Laetsch…

...On the science behind T-cell therapy:

“This is a new type of immunotherapy, where we take a patient’s T-cells out of their body, which are their normal immune-fighting cells, send them to a laboratory where they’re engineered to then attack the leukemia, and then re-infuse them. There, they’re able to attack and kill the leukemia and grow and proliferate, so that they may be able to control the leukemia for a long period of time. These are actually live T-cells that we give back to the patient and then grow and attack the leukemia – much in the same way that your immune system fights a virus when you get a cold.”

...On how this new therapy differs from conventional cancer treatment:

“Previously, our therapies have relied on cytotoxic chemotherapy, which [are] drugs that we give that kill cells that are growing quickly in your body. Those drugs have a lot of side effects because they also kill normal cells that grow quickly. That’s why they make patients lose their hair or have low blood counts. This therapy is entirely different from that. Instead of just attacking fast-growing cells, we’re attacking cells that have a specific marker on them. It’s a marker that’s on the cancer cells, and so we can train the immune system to attack and kill those cells, and we hope to maintain that remission by continuing to watch for those cells and kill them as they develop.

Credit Courtesy of UT Southwestern Medical Center
Dr. Theodore Laetsch is a pediatric oncologist at UT Southwestern Medical Center and Children's Health in Dallas. He lead the clinical trials for the T-cell cancer therapy in Texas.

“There’s been interest in using your own immune system to fight cancer for a long time, but this specific therapy has only been developed within the past few years. So the first child treated with this drug was only treated about five years ago, so this has been a very rapid development of this therapy for kids with leukemia.”

...On the impact of this therapy:

“The data we’ve seen so far with the study we’ve been conducting shows that over 80 percent of children treated with this therapy with relapsed leukemia will go into remission. That’s markedly better than anything we’ve had in the past, where less than 50 percent and many times, less than a quarter, of patients will go into remission with relapse therapies. This is a real breakthrough for those kids.”

...On whether this therapy can treat other cancers:

“The specific therapy that’s been developed is targeting B-cells, which are a normal part of your immune system responsible for making antibodies. So there are other cancers of B-cells that are also being studied, including a cancer that more commonly occurs in adults: diffuse large B-cell lymphoma. There’s also interest in whether we can apply this to other cancers that aren’t related to B-cells – and then you’d need to design a different target for these cells to attack. There are ongoing clinical trials, none of them quite as advanced as this therapy for children with leukemia.”

...On the prospect of curing cancer completely:

“Curing cancer all together is a very difficult task. Cancer is not just one disease but many, many diseases, and as we’ve been able to do and learn more about the genetics of cancer, we’ve actually learned that it’s even more diseases than we thought. It’s not just each individual type of cancer, but their individual mutations that cause cancer within each of those types. So I think the goal of curing everyone with cancer is absolutely our goal, but that is a long way away. I think the development of this first immunotherapy where we’re able to engineer a T-cell to attack a patient’s cancer is a major step that may help us fight some of those cancers where there is a good target on the cancer that we can attack.”