Transplanting organs is difficult because the host’s body rejects the foreign tissue. Since mesenchymal stem cells are anti-inflammatory and can modulate an immune response, one company has been trying to help the dreaded disease of severe organ rejection (GVHD or Graft vs. Host Disease). This company placed someone else’s mass manufactured stem cells in a vial in a cells=drugs product called Prochymal, the goal being to use the cells to block this formidable host immune response. The problem was that the stem cells in a vial didn’t work so well. This ultimately lead to one big pharma player pulling out of the deal to commercialize the cells as drugs. On the heels of that news comes a study this week out of Northwestern that shows that kidney transplant patients given the bone marrow of the donor did remarkably well, with 5/8 patients not needing anti-rejection drugs. The researchers filtered out the cells from the donor’s bone marrow that they wanted and tamped down the immune system of the host to make room for new the new cells to establish a secondary immune system. This concept called Chimerism means that the host has two immune systems, so it recognizes the donor kidney as it’s own tissue. The other three patients are only on a single anti-rejection drug.
So we have two approaches here that illustrate our cells=drugs problem nicely. One approach focused heavily on the commercialization of a drug-Prochymal. The drug route took the cells of young donors and mass manufactured those as a drug. The other approach takes an individualized and less pharma centric approach of using cells to prevent disease. There’s another difference-Prochymal was also used in a much harder to treat medical condition-GVHD. One the other side of the coin, the Northwestern surgical procedure was focused on preventing rejection. Why the difference here? The company behind Prochymal needed a big splash for Wall Street whereas the Northwestern physicians were simply trying to fix a problem they saw before them. This same transplant program chimed in on the cells=drugs policy, stating that the current cell transplants being performed by the program were the practice of medicine and only should be controlled under regulations meant to protect patients from communicable disease. The upshot? A customized surgical procedure that aimed to fix a clinical problem has bested the efforts of a pharma cells=drugs trial. While more research needs to be done by the Northwestern team, since almost nobody gets to forego anti-rejection drugs in this kind of transplant, 5/8 tells a significant scientific story. In addition, since these drugs are incredibly expensive and have high side effects-the patients win. Finally, because these expensive drugs are paid for by society though public funding or private health insurance premiums and may not be needed, it’s not hard to see why pharma is concerned and wants to turn your cells into drugs.