In a first-of-its-kind trial in the United States, researchers are testing a stem cell-derived natural killer cell immunotherapy in people with incurable cancer. Share on Pinterest Natural killer cells can detect and destroy cancer cells. Cancer follows heart disease as the second biggest killer worldwide. In the United States, an estimated 606,880 people will die due to cancer in 2019. With the advent of immunotherapy, researchers hoped to boost a person’s immune system to fight and destroy tumors effectively. Although this type of therapy has completely changed the treatment landscape for cancers such as melanoma, there remain a significant number of people whose tumors can evade their immune system. Joining the likes of adoptive cell transfer and checkpoint inhibitors on the list of immunotherapies are natural killer (NK) cells. These specialized white blood cells come equipped with a potent armory of tools to make short work of cancer cells. Now, researchers at the University of California (UC) San Diego School of Medicine are running a clinical trial with industrial collaborator Fate Therapeutics to investigate NK cells both alone and in combination with checkpoint inhibitors in people with advanced solid tumors. One particular factor sets this study apart from others using NK cells for similar purposes. This “off-the-shelf” NK immunotherapy trial is the first in the U.S. to use cells that the researchers have derived from induced pluripotent stem (iPS) cells.

Using stem cells to kill cancer Scientists first developed iPS cells in 2006 by switching on four dormant genes in skin cells. Doing this completely changed the characteristics of these cells and reverted them to an embryonic-like state. Now widely hailed as an alternative to embryonic stem cells, iPS cells can, like their embryonic counterparts, develop into any type of cell. For scientists who work on cell therapies, this provides a solution to a major stumbling block in advancing their technologies to clinical application. Many therapies make use of a patient’s own cells or cells from a donor. While this type of personalized treatment is the mainstay of current cell therapy applications, it is costly and time-consuming. The use of iPS cells, on the other hand, allows researchers to produce a never-ending stream of cells. All that they need is a robust method to turn iPS cells into the particular cell type that they require. A single iPS cell can thus become an “off-the-shelf” source of cells for therapy, which it is easy to produce time and time again. Back in 2013, Dr. Dan Kaufman — professor of medicine in the Division of Regenerative Medicine and director of cell therapy at UC San Diego School of Medicine — and his team developed a method of expanding large numbers of NK cells from human iPS cells for cancer therapy. They published the method in the journal Stem Cells Translational Medicine. After extensive preclinical testing, the Food and Drug Administration (FDA) gave Dr. Kaufman and Fate Therapeutics the go-ahead last November to set up a phase I clinical trial to test their iPS-derived NK immunotherapy in people with advanced solid tumors.