Many governments, including the U.S. and Japan, are well aware of the dangers to their populations of exposure to high levels of radiation from nuclear accidents or dirty bomb attacks. Whereas Japan’s population was recently exposed at Fukushima following the tsunami of 2011, the U.S. Department of Defense has been stockpiling acute radiation syndrome (ARS) countermeasures as a precaution for many years.
As described in a recent Reuter’s article:
‘The escalating threat of a potential nuclear war between North Korea and the United States has led the Department of Defense to join hands with a clutch of companies in developing more effective medical treatments for acute radiation syndrome….Pluristem Therapeutics Inc, Cleveland BioLabs and privately held Neumedicines Inc are all in the final stages of developing their treatments, while Humanetics is yet to initiate an early-stage trial for its oral drug.”
The hematologic component of ARS results from damage to the bone marrow and is characterized by acute decreases in red and white blood cell and platelet counts, which can lead to infection, hemorrhage and death. Importantly, Pluristem’s cell therapy product, PLX-R18, has demonstrated improvement in the recovery of white blood cell, red blood cell, and platelet levels in animals exposed to high levels of radiation.
Preclinical data shows that PLX-R18 cells secrete a range of specific proteins that trigger the regeneration of bone marrow hematopoietic stem cells, thereby supporting the recovery of blood cell production after exposure to life threating levels of radiation. It is also the only potential ARS antidote that can boost production of all three blood components: white blood cells, red blood cells, and platelets.
PLX-R18 is particularly well suited for stockpiling, because it is an off-the-shelf cell therapy, does not require tissue matching, and has a shelf life of three years. As importantly, Pluristem’s product can be administered in a few minutes by injecting it into the muscle with a simple syringe, requires no pre-screening or blood tests, and no dose calculations. There is no need for follow up tests either. Currently, there are no comprehensive counter-measuremes to treat the hematologic component of ARS post exposure to radiation, which makes PLX-R18 a cutting-edge solution.
According to Dr. Racheli Ofir, VP of Research & Intellectual Property at Pluristem, “The cells secrete a broad array of cytokines such as MCP-1, IL-6 and IL-8 that contribute to the reconstitution of the hematopoietic system.”
Pluristem’s PLX-R18 is manufactured at the company’s wholly-owned facility using patented bioreactors which provide the cells with a three-dimensional microenvironment in which to grow. Pluristem’s propriety bioreactor technology provides full-scale cell manufacturing capabilities that allow it to expand trillions of cells and create a commercial-grade product.
Originating from placental cells, PLX-R18 has a unique therapeutic secretion profile and characterization, which is achieved by precisely controlling the environment in which the cells are cultured. Pluristem uses the high surface-to-volume ratio of three dimensional (3D) non-woven scaffolds in its bioreactors, resulting in a system which is many times more efficient than the current 2D methods of cell culturing.
FDA approval of PLX-R18 for ARS could generate U.S. government interest in stockpiling it for use in the case of a nuclear disaster, because PLX cell products are ideally suited for rapid initiation of treatment of large populations, do not require tissue matching prior to administration, and can be administered quickly via intramuscular injection. The U.S. Department of Defense is studying PLX-R18 in parallel for prevention as well as treatment of ARS.
In times of global threats, the free world is looking for a global solution, and PLX-R18’s properties make it a potentially ground-breaking treatment for the hematologic component of acute radiation syndrome (ARS).
