They are literally natural-born cancer killers: NK (natural killer) cells are made by the body to rapidly detect and effectively destroy malignant cells of all kinds, including cancerous liquid tumors, such as those typical of leukemia.
Doctors are now capable of producing engineered NK cells from human stem cells and transplanting them into cancer patients. And while the use of NK cells as an immunotherapy has been shown to be safe and effective in mouse studies and early clinical trials, harnessing them as an effective tool has so far been hampered by several factors, including their lack of persistence once transplanted and the inability to manufacture them in large enough quantities to make them clinically relevant.
University of Minnesota researchers are trying to overcome those problems via a research collaboration with San Diego-based Fate Therapeutics (Nasdaq: FATE), which has announced it is seeking “investigational new drug” status for a new NK cell therapy developed by Dr. Jeffrey Miller, deputy director of the U’s Masonic Cancer Center.
An IND is usually a precursor to a Phase I human clinical trial.
Dr. Miller, who as TCB reported last week
, is also working separately on a “tri-specific killer engager” NK cell program with Oxis International (OTCQB: OXIS), will begin work on the new IND this year, according to Fate Therapeutics President and CEO Scott Wolchko.
The U researcher is recognized as one the world’s leading experts on the potential of NK cells as cancer-fighting agents and has 10 years of experience in seeking ways to translate that promise. The cells are essential components of the innate immune system and play a critical role in host immunity against cancer—those attributes are quickly elevating them to the forefront of the cancer immunotherapy world.
NK cells can be produced from the stem cells of a donor, and genetically altered to be more effective. One big plus about NK cells is that, unlike currently standard T-cell therapy for leukemia, they do not attack healthy tissues, making it more likely that an NK-based anti-tumor effect can be achieved without the problem of graft-vs.-host disease.
Early results have shown NK cell therapy can be quite effective in reducing cancer, but a number of factors limit its application, such as the failure of transplanted NK cells to expand and persist in vivo
Miller and Fate, however, are touting the results of their collaboration, in which the researcher used the company’s “cell programming” capabilities to produce an “adaptive” NK cell cancer immunotherapy that boasts “enhanced anti-tumor activity, including improved persistence,” enhanced tumor-killing production and “increased resistance to immunosuppressive factors in the microenvironment.”
The company also asserts their drug candidate is able to synergize with “several different therapeutic antibodies” in vivo
, and thus can be guided toward solid tumors as well.
Wolchko told analysts during a conference call that the IND and subsequent clinical trial will be geared toward addressing acute myeloid leukemia (AML).
“Jeff Miller has done a lot of work historically with NK cell therapies, and he has done correlative analysis that suggests persistence is very important and tied to patient outcomes,” the CEO said. “So one of the early biomarkers that we will look at in the AML study is the persistence of our adaptive NK cells.
“His approach in adapting NK cells emphasizes multi-faceted killing potential. We think it is unique when we compare that cell type with other NK cell types, including the types that Jeff is currently treating patients with. So clearly we think this is major step forward in the development of NK cell therapies.”
Another key aspect of the collaboration between Fate and the U of M researchers is the company’s stem cell technology platform, which enables production of NK cells in large enough quantities to make the them available “off the shelf,” rather than producing them one patient at a time. That aspect is being headed by a former U of M researcher: Dan Kaufman, M.D., who moved to the University of California—San Diego in February.
Described as a pioneer in deriving NK cells from undifferentiated pluripotent or “master” stem cells, Kaufman is using Fate’s platform to create an immune-engineered pluripotent cell source to enable the production of "off-the-shelf" NK cell-based targeted immunotherapies.
“We believe a tectonic shift toward off-the-shelf engineering of cellular immunotherapies using renewable pluripotent stem cell lines is now underway,” Wolchko told analysts.
Under the terms of the collaboration, Fate has the option to gain exclusive patent rights to all intellectual property arising from the partnership. The company has also secured an exclusive option to “certain background intellectual property” of the University of Minnesota, while Drs. Miller and Kaufman are serving as advisors in the development of cell-based immunotherapies, including those derived from induced pluripotent stem cells.