BURLINGTON, Vt. — There are several steps to the innovative Car T cell treatment.

In a process called leukapheresis, T cells are removed from the patient and then taken to a lab for modification. T cells are a type of white blood cell used by the immune system to kill viruses and other foreign bodies.

–

Blood out, blood in

–

As well, another process is implemented as the T cells are removed.

“There’s this process called apheresis where we remove blood, and then the T-cells get extracted from that, and then the blood is immediately put back into a patient,” Dr. James Gerson, director of the CAR T Cell Program at UVM Medical Center, said.

“There’s actually a continuous circuit that the patient sits on for a couple hours and it just takes out their blood, takes out the T-cells, puts it back in, so when they leave the center they feel exactly the same as when they came in.”

While the T cells are in the lab, a receptor gene called a “chimeric antigen receptor” or CAR is added onto the cell. These cells are then given back to the patient, now having the ability to recognize a protein on the cancer cell and attach to it, killing the cancer cell, doctors explained.

For the treatment, a couple million T cells are initially needed from the patient, “which sounds like a lot, but it’s actually teenie tiny,” Gerson said.

The dosage is two to three million T cells per kg body weight that are put back into the patient. For example, a 70 kg person, which is about average, would receive 140 million of their own T cells that have been genetically modified, Gerson said.

–

Pros and cons

–

Even though this treatment is quite revolutionary, it has its cons, doctors explained. One of those being a side effect called cytokine release syndrome (CRS), which is sort of similar to an overactive immune system.

Gerson said this occurs because the T cells that are put back into the patient are almost supercharged, having an over-exuberant response trying to kill the cancer cells. This manifests into symptoms such as fevers or high fevers, organ dysfunction and low blood pressure.

If the symptoms are mild they can be managed outside the hospital, but if they are severe, the patient will be admitted.

However, incidents of these symptoms have dropped dramatically, Gerson said. It was more of a concern when these treatments were first given, but providers have become adept at managing it preventatively and when it occurs.

–

Non-blood cancers

–

As well, another drawback is its inability to be applied to other forms of cancer. It was originally effective in lymphoma and expanded to other blood cancers, but when treatment was tried in solid tumors like breast cancer, lung cancer or colon cancer, it did not work.

“For a variety of reasons we don’t quite understand, to be completely honest, it doesn’t work as well for non-blood cancers, but this is an area of active research,” Gerson said.

–

Expense of treatment

–

On top of that, the cost for this therapy is tremendous.

“The engineering process makes this a very expensive therapy,” Gerson said.

This treatment typically costs approximately $400,000, Dr. Randall Holcombe, director of UVM Cancer Center, said.

Although, because this therapy is FDA approved, insurance companies cannot deny this treatment’s legitimacy, thus for the vast majority of patients, this treatment is covered to some degree.

“We’re going to be working closely with insurance companies to make sure that this is covered and it would never be given if there was any question of coverage,” Gerson said.

“Doing nothing obviously is in many ways more expensive than doing this expensive therapy.”