Genetically modified immunotherapy shows ‘unprecedented’ success

Scanning electron micrograph
of a human T cell Credit: NIAID

CANCER DIGEST – Feb. 16, 2016 – Immune system cells engineered to attack cancer cells raised optimistic “alerts” in the mainstream media this week, as a researcher reported 94 percent of patients with advanced acute lymphoblastic leukemia (ALL) saw their symptoms disappear.

The results were reported at the just concluded American Association for the Advancement of Science conference in Washington, DC, by Dr. Stan Ridell, of Fred Hutchinson Cancer Research Center in Seattle, WA.

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

His presentation didn’t state how many patients were involved in the studies, but the Guardian article cited the most promising trials as involving 35 patients with advanced stage ALL and underwent the T cell treatment. Of those, 94 percent went into remission. In a trial involving non-Hodgkin’s lymphoma the remission rate was 80 percent. Remission is not a cure, but indicates the treatment is working, which is significant in these patients as all conventional treatments had stopped working.

What is different about this immunotherapy is that it involves removing immune cells from patients and genetically modifying them to produce a protein on the cell surface that specifically targets cancer cells, then infusing the cells back into the patient. Thus the researchers are combining gene therapy with immunotherapy in an approach called adoptive T-cell transfer, which in effect creates a living drug in the patient. 

The researchers are hopeful these genetically modified T cells will be potent and longer-lasting and have fewer side effects than earlier T cell therapies.

A word of caution, the clinical trial results presented have not been published in a peer-reviewed journal, and the trials were funded by Juno Therapeutics, which has partnerships with Fred Hutchinson Cancer Research Center, Memorial Sloan Kettering and Seattle Children’s Research Institute. Dr. Riddell is also a founding researcher of the company.