In a major shift earlier this year, the induced pluripotent stem (IPS) cell trial in Japan for treatment of macular degeneration (MD) switched gears from using the patients’ own cells (called “autologous”) to using banked cells from other people, termed “allogeneic”.
Dr. Masayo Takahashi, the leader of this MD trial indicated the main reason was due to regulatory changes related to stem cells in Japan. This decision has delayed the clinical study, but there is hope it will restart soon. It appears for some as yet unknown reason the Japanese government has decided to only allow the use of allogeneic, matched IPS cells from cryobanks.
Now a second clinical study in the works in Japan also using IPS cells but as the basis for treatment of Parkinson’s Disease (PD) appears to be following suit. The PD trial, run by Dr. Jun Takahashi (pictured above; spouse of Masayo Takahashi, making them the world’s stem cell power couple), reportedly will also switch to focus on allogeneic cells.
The advantages of allogeneic cells include the fact that they can be validated and batch prepared in advance. In theory in this allogeneic system there might be no waiting period for patients while their own cells are turned into IPS cells. However, finding matches from a bank of IPS cells may prove somewhat difficult for allogeneic use for some patients. Even with major HLA type matching, minor mismatches could lead to some level of rejection. This could necessitate the use of immunosuppression. By contrast, autologous use of IPS cell-based products would likely require no immunosuppression after transplantation.
Together these changes in IPS cell clinical plans suggest a significant, broader shift in the field potentially toward allogeneic use of IPS cells. It’s not clear if other groups with IPS cell-based therapies in the translational pipeline, including in other countries, will follow suit or stick with the originally hoped for autologous focus.