Potential of iPSC for Medical Application
In 2007, Dr. Shinya Yamanaka announced the establishment of human iPS cell. As a result, the ethical issues of using ES cells in regenerative medicine were no longer an obstacle. ① [Cell transplantation treatment / regenerative medicine] Confirming the safety of the cells taken from differentiated iPS cells, it was discovered that restoring specific functions to areas of lost function or hypofunction was possible by transplanting cells to the site, ② [Pathological elucidation / drug evaluation] through comparisons of iPS cells from diseased patients and those from healthy individuals, it has become possible to elucidate the pathological mechanisms and make use of it in therapeutic drug screenings.
History of spinal cord regeneration research using iPSC
Keio University has found effective results showing recovery of motor function by transplanting neural progenitor cells differentiated from human iPSC in the subacute SCI models of mice, rats, and marmosets. On the other hand, in a chronic SCI model, the effects of treatments combined with rehabilitation has shown results. We are proceeding with non-clinical trials targeting the subacute SCI and are preparing for the start of clinical trials. We are also investigating chronic SCI diseases.
Drug discovery research utilizing diseases-specific iPSC
Significance of drug discovery
Up until this point in drug discovery research, the standard evaluation of drug efficacy has been to screen for efficacy through in vitro and based upon test results test on animal models before extrapolation to humans. As a result, the success rate of human clinical trials is extremely low. We have established iPSC from blood cells received from patients, created diseases-specific in vitro screening systems, and developed a method to find candidate compounds from existing drug libraries as well as new compound libraries. This evaluation system reflects human pathology and we regard it as an innovation in drug discovery research that shows the possibility of proceeding to clinical trials without using conventional animal models for testing.
About Drug repositioning
Identification of new candidate compounds is possible via a newly discovered in vitro evaluation screening system used on compounds already approved as pharmaceuticals. The ability to use existing pharmaceuticals has merit, as existing data of pharmacokinetics and safety are accessible, and makes it possible to accelerate a pharmaceutical to clinical application. Although the hit rate in vitro screenings system is high, there will be a possibility to escalate drug price setting based on its potential to treat boarder range of diseases. However, the possibility of introducing the concept of price setting as a new drug in rare diseases can be expected.
Research on intractable neurological diseases
Keio University, with informed consent, has established iPS cells from blood cells obtained from patients with intractable neurological disorders, and is elucidating its pathophysiology. At the same time, we are reviewing the development of a new compound screening system. We aim to steadily advance clinical trials of compound candidates found in joint research with pharmaceutical companies and deliver them to patients as soon as possible.