Currently the first trial of engineered stem cells for macular degeneration, a retinal disease that can lead to blindness, are beginning in Japan. The endpoint in the first patient will be for safety, NOT for efficacy. IMO this is the way the FDA is likely to proceed in the U.S.: very carefully, safety first.
This is different from the previously reported Aldagen trial for stroke, which used only separated stem cells from the bone marrow, in that in the Japanese study they are using induced stem cells (from the patient) that have been grown in the lab to reproduce the exact tissue in need of repair. In other words, they have been altered to perform the job required. Clinical standards for an induced stem cell will necessarily be higher, in order to make sure no unanticipated changes- think cancer – are caused by the reprogramming. one concern is how long you should wait before deciding such an issue. The retina may be a good place to begin because it is so easily observed.
Some of my patients have been convinced by others to have simple bone marrow aspirate injected as a kind of “stem cell therapy”. This has been done without adequate scientific proof and at extremely high cost, no insurance accepted. As they say, it can be easy to separate a fool from his money. Bone marrow may be a source of stem cells, but they are certainly rare. Without validation- counting cells- I oppose “selling” BMA as a stem cell therapy. The public should be educated as to the true state of the art, and how we must proceed cautiously, and then measure the outcomes such that we make the technology reproducible, affordable, and effective.