T-cell therapy shows ‘extraordinary’ results in patients with terminal blood cancer

A new cancer therapy that uses immune cells to target blood cancer has had “extraordinary” success in clinical trials. A staggering number of patients went into remission or saw their symptoms disappear, despite being told they only had months to live.

The T-cell therapy involves the removal of immune cells from patients. Those cells are tagged with “receptor” molecules that target a specific cancer. Doctors then place the cells back in the body.

Of the 35 patients with acute lymphoblastic leukemia (ALL) who were treated in the trials, a staggering 94 percent saw their symptoms vanish completely after undergoing T-cell therapy.

More than 40 patients with lymphoma experienced remission rates of more than 50 percent, while a group with non-Hodgkin's lymphoma experienced diminished cancer symptoms in more than 80 percent of cases.

The therapy's success rate is particularly remarkable because the patients were thought to only have months to live.

“These are in patients that have failed everything. Most of the patients in our trial would be projected to have two to five months to live,” researcher Stanley Riddell, of the Fred Hutchinson Cancer Research Center in Washington State, said during a speech at the annual meeting for the American Association for the Advancement for Science (AAAS), according to the Guardian and other British media outlets.

“This is unprecedented in medicine, to be honest, to get response rates in this range in these very advanced patients,” Riddell said.

Researcher Chiara Bonini, a hematologist at San Raffaele University in Milan, called the therapy a “revolution,” stressing that T-cells are a “living drug” and “have the potential to persist in our body for our whole lives.”

T-cells are an integral part of the body's immune system, helping to identify viruses and bacteria. They have the potential to keep a “memory” of previous infections, in order to launch a rapid immune response when the body comes under a repeat attack.

Bonini, who believes the findings could lead to a long-term defense against cancer, noted that T-cells can remember an infection from 10 years earlier and “kill it so quickly you don't even know you're infected.”

T-cell therapy has typically been considered a last resort option, because reprogramming the immune system can come with serious side effects and overload defense cells. One of the most serious side effects is cytokine release syndrome (sCRS), which can be fatal.

Twenty of the patients in the study suffered from fever, hypotension, and neurotoxicity induced by sCRS, and two participants died. The researchers noted, however, that chemotherapy had failed in these patients and no other options were available to them.

The trials have so far only targeted blood cancers. The researchers acknowledged that they need to work on tumors and track how long patients remain in remission after T-cell therapy.

Riddell also noted the scientists have “a long way to go,” acknowledging that “some of these patients do relapse.” He stressed that researchers should be focused on “how to bring [the treatment] forward."

“We don't want to wait until patients have failed everything else,” he said.

A paper on the research is currently under review and pending publication.