Kyoto University will embark on a clinical trial of the immunosuppressant drug rapamycin in patients with fibrodysplasia ossificans progressiva (FOP) after discovering that the drug slows down the progression of FOP in studies using induced pluripotent stem (iPS) cells.
The findings, which were made by the university's Center for iPS Cell Research and Application (CiRA), were released on the online version of the Journal of Clinical Investigation website on Aug. 1.
According to CiRA team member Junya Toguchida and others, FOP occurs in about 1 in every 2 million people, and about 80 people are believed to have the illness in Japan. The disease causes fibrous tissue such as muscles and tendons to change into bone.
CiRA plans to administer the drug in patients with FOP in a clinical trial at nearby Kyoto University Hospital, with the goal of receiving government approval of rapamycin as a drug to treat the additional indication of FOP. CiRA's planned clinical trial is the first case in the world of a drug being tested based on studies involving iPS cells.
In the studies, the team used iPS cells originally collected from FOP patients, and then modified them to mimic FOP cells. Subsequently, a total of 6,809 drug compounds were applied to the cells, in addition to the cytokine Activin A.
With the objective of discovering which of the 6,809 compounds would inhibit bone formation, it was found that rapamycin, which is used to facilitate organ transplants, was effective. In addition, after administering rapamycin in mice with FOP-state cells, it was found that bone formation inside the animals' muscle tissue was inhibited.
According to Toguchida, it is planned that the clinical trial will take place in 20 patients with FOP from September onward, over a 52-week period. In addition, Nobel-prize winner Shinya Yamanaka, who is the head of the CiRA team, says, "Starting with this clinical trial, I expect that drug development through iPS cells will become increasingly common, and lead to the development of drugs aimed at treating various intractable illnesses."
Drug development using iPS cells consists of the creation of such units by collecting cells such as skin cells from patients, and then making them mimic a particular illness -- with the aim of finding substances that can treat that illness. The clinical trial planned by CiRA is the first example of such a trial being conducted on the basis of successful studies using iPS cells. The technique is believed to have the potential to treat a wide range of complicated diseases.