Exacis Biotherapeutics Develops mRNA-Engineered iPSC-Derived NK Cells for Difficult-To-Treat Tumors

Exacis Biotherapeutics

  • Exacis has generated NK cells from iPSCs engineered using mRNA gene-editing technology to resist rejection by the patient’s immune system
  • ExaNK™ cells show superior tumor cell-killing activity and cytokine production compared to peripheral blood-derived NK cells
  • Using iPSCs to develop off-the-shelf products avoids the need for donors
  • Provisional patent application filed; data to be presented at a major conference later this year

Cambridge, MA, March 24, 2021 – Exacis Biotherapeutics Inc., a development-stage immuno-oncology company working to democratize access to the most advanced and effective cancer treatments, today announced several important steps in the preclinical development of its ExaNK™ engineered NK cell-therapy candidates.

ExaNK™ cells are generated from induced pluripotent stem cells (iPSCs) that are made using mRNA-based cell-reprogramming and gene-editing technologies. ExaNK™ cells are designed to resist rejection when administered to patients, with the goal of reducing or eliminating the need for costly and dangerous lymphodepletion, a procedure normally performed using cytotoxic chemotherapy, which carries risks of neurotoxicity and infection. These engineered iPSCs will form the basis for Exacis’ tumor-targeted ExaCAR-NK™ cells as well as non-CAR-bearing ExaNK™ cells designed to improve the effect of monoclonal antibodies against both liquid and solid tumors.

Exacis produces rejection-resistant ExaNK™ cells by performing functional editing of key stealthing targets in its proprietary mRNA-reprogrammed iPSCs. These engineered iPSCs are then differentiated to the final NK-cell product using Exacis’ proprietary high-yield differentiation process. The resulting ExaNK™ cells show higher tumor cell-killing activity and cytokine production in vitro than peripheral blood-derived NK cells, with no evidence of self-killing (i.e., “fratricide”).

Exacis develops its off-the-shelf products using iPSCs to avoid the need for donors. This approach aims to lower the cost and increase the availability and consistency of engineered immuno-oncology cell therapies in comparison to currently approved products.

The discoveries announced today were made in collaboration with Exacis’ parent company, Factor Bioscience, and have been submitted for presentation at a major conference later this year. Exacis has also disclosed the details of these discoveries in a provisional patent application filed earlier this month.

“These results illustrate the sound scientific basis for Exacis’ approach to the development of next-generation engineered NK-cell therapies,” said Matt Angel, PhD, CEO of Factor Bioscience and Chair of Exacis’ Scientific Advisory Board. “Combining cell reprogramming with gene editing allows the production of a near-unlimited supply of genetically uniform engineered cells, while using mRNA for both the cell-reprogramming and gene-editing steps uniquely enables the generation of footprint-free cells with no risk of vector integration.”

“We continue to be encouraged by the rapid progress we are making towards developing accessible, next-generation engineered cell therapies that will improve patient experiences and outcomes. This first opportunity to expand our substantial intellectual property portfolio marks a key milestone for the company” stated Gregory Fiore MD, CEO and President of Exacis Biotherapeutics.

Next steps for Exacis include scaling the iPSC expansion and differentiation processes to prepare for IND-enabling studies to be conducted later this year.

About Exacis Biotherapeutics

Exacis is a development stage immuno-oncology company focused on harnessing the human immune system to cure cancer. Exacis uses its proprietary mRNA-based technologies to engineer next generation off-the-shelf NK and T cell therapies aimed at liquid and solid tumors. Exacis was founded in 2020 with an exclusive license to a broad suite of patents covering the use of mRNA-based cell reprogramming and gene editing technologies for oncology. For more information, visit www.exacis.com.

ExaNK™, ExaCAR-NK™ and ExaCAR-T™ utilize mRNA cell reprogramming and mRNA gene editing technologies developed and owned by Factor Bioscience. Exacis has an exclusive license to the Factor Bioscience technology for engineered NK and T cell products derived from iPSCs for use in oncology and holds all global development and commercial rights for these investigational candidates.

About Factor Bioscience

Founded in 2011, Factor Bioscience develops technologies for engineering cells to advance the study and treatment of disease. Factor collaborates with academic and industrial partners to develop therapeutic products based on its mRNA, gene editing, cell reprogramming, and nucleic-acid delivery technologies. Factor Bioscience is privately held and is headquartered in Cambridge, Massachusetts. For more information, visit www.factorbio.com.

About Natural Killer (NK) Cell Therapies

NK cells are a type of human immune cell that is able to recognize and kill cancer cells and can be modified through genetic engineering to target specific tumors.


Contact Exacis Biotherapeutics for further information and media:

Exacis Biotherapeutics

Ted Agne
The Communications Strategy Group Inc.
+1781 888 0099