Cancer-hunting 'T cells' used in pioneering new treatment
City of Hope hospital and research center in Duarte is pioneering a new way to treat cancer that involves genetically modifying a patient’s own immune system so it can better detect and attack tumors.
Clinical trials are still in early stages, but the approach is catching on and could be a big step forward for the field.
Patient Cherie Payne was part of an experimental study to test the procedure. She was diagnosed with a rare blood cancer known as mantle cell lymphoma in the summer of 2013. By the time doctors discovered it, the cancer had spread to 60 percent of her bone marrow.
At first, she panicked. But the 63-year-old native Angeleno quickly changed her perspective.
Payne worked for years as a project manager at the Studio Actor's Guild pension and health plan, so she was use to tackling tough problems.
"I think my project management just kicked in," she recalled. "What do I need to, how long is it going to take, what should I expect? I just had lay it all out."
Using referrals, message boards and an uncanny ability to schedule her life even in turmoil, Payne found City of Hope in fall of 2013.
She signed up for an experimental trial that involved modifying a key part of the immune system called a T Cell.
"They just had a high level of confidence that this was going to work," Payne said of the new treatment.
T cells are white blood cells that are experts at attacking and killing harmful stuff in the body.
But according to City of Hope researcher Stephen Forman, cancers have a way of hiding from these cells.
The cancer cell also produces things that can inhibit the immune system from attacking, he added.
"What we are doing, is saying 'we are going to re-engineer the system so [the cancer] can be seen and can be eliminated."
To do that, his team needs to alter the DNA of these T cells, which they do in a big, sterile lab.
There, researcher Sarah Wright carefully places drops of liquid filled with DNA into clear goo using a pipette.
She then fires up a machine that separates the DNA into different sized strands, so she can pick out certain parts.
After that, Wright uses enzymes to cut and paste together the blueprints for cells.
"We have a whole library of DNA constructs and we can take different pieces of different ones and put together exactly what we want."
The DNA built in this lab carries instructions that help a T cell grow the special receptor it would need to target a certain kind of tumor.
A virus is used to transmit this DNA into the patient's T cells explained associate research director Christine Brown.
"So what we do is put a new receptor on the T cell and [it] says 'okay, now this is what you are going to recognize, target and kill."
It’s sort of like giving the T cell a wanted poster with a specific kind of cancer on it. The T cell becomes a targeted bounty hunter for the tumor.
Once these modified cells are ready, they are transfused back into the original patient.
If all goes to plan, the modified cells will be able to target and eliminate the specific type of tumor.
"That’s our goal... to reconstitute the patent’s immune system with cells that will always recognize and destroy their cancer," Brown said.
In mouse studies, this technique was very effective and City of Hope is in the process of getting FDA approval for larger trials with humans.
Stephen Lo researches cancer at UCLA. He said so-called immunotherapies are a growing field, but they have drawbacks.
"The access to this very limited and the cost will be exorbitant at the present stage," he explained.
That’s because every treatment has to be tailored to the patient's unique immune system and cancer. The work also requires a sophisticated lab. All of this can cost tens of thousands of dollars.
Lo said there’s also some concern that some cancers will become immune to these new T cells or that the modified cells will attack healthy parts of the body.
"That concern is becoming less and less as we understand more and more about cancer immunology," he noted.
For patient Cherie Payne, so far the new T cell therapy seems to have cleared her of the lymphoma.
The experience changed her though and she's decided to take an early retirement later this year.
However, since her organizational skills served her so well in dealing with her cancer, she’s going to keep them active.
"I’m handling my retirement just like a project plan," Payne laughed.
"I’ve rented a farmhouse in Italy.... and going to Rome and just planning some trips and doing some stuff."