Leukemia Immunotherapy Successful in Small Trial

Investigators recently announced positive results from a small study involving a novel immunotherapy used in patients with acute myeloid leukemia who were at high-risk of relapse.

In the trial, patients received genetically engineered immune cells following a bone marrow transplant. Results from the study were presented at the American Society of Hematology annual meeting, and could potentially guide targeted treatments for these patients.

Of the 12 patients included in the trial, all achieved remission, and are still in remission after more than 2 years, according to the study. Investigators believe that this experimental therapy may prevent patients who are at a high-risk of relapse from experiencing relapse in the future.

These findings were the direct opposite of the outcomes in patients who received a stem cell transplant around the same time, but did not receive genetically engineered T cells. In these patients, all experienced remission initially, but more than 25% experienced remission within 10 months, according to the study.

To create the engineered T cells, the researchers altered the cells to create receptors to recognize the target molecule WT1. This molecule is 10 to 1000 times more common in leukemia cells compared with healthy cells, making an excellent target for these treatments, according to the authors.

Since it was the first use of this treatment strategy, patients enrolled were diagnosed with acute myeloid leukemia, were undergoing bone marrow transplant, and also had genetic or disease characteristics that reduced their change of long-term remission following transplant.

Each of the 12 patients received personalized, genetically modified T cells, and certain cells were given the genetic instruction to produce a receptor that reacts to WT1, according to the study.

A month after the blood stem cell transplant, researchers discovered that there were no traces of the cancer in any of the patients’ bone marrow. After this discovery, patients then received an infusion of up to 10 billion engineered donor T cells.

If this method proves to be as successful in a larger group of patients, those at high-risk of relapse after a stem cell transplant may have an alternative treatment option that will prevent disease relapse.

Lead study author Aude Chapuis, MD, said that she has seen many patients undergo bone marrow transplants, which is what drove her and the team of researchers to work towards a more effective treatment.

"That's my source of inspiration. I'm always horrified by the intense treatment that we inflict on bone marrow transplant patients and the hardship that we make them go through. And I really think we can do better," Dr Chapuis concluded. "That's why I'm doing this."