The number of clinical trials using human pluripotent stem cells (hPSC) - both embryonic and induced pluripotent stem cells (hESC/iPSC) - has expanded in the last several years beyond expectations. By the end of 2021, a total of 90 trials had been registered in 13 countries with over 3000 participants. However, only USA, Japan, China, and the UK are conducting both hESC- and hiPSC-based trials. Together USA, Japan, and China have registered 78% (70 out of 90) of all trials worldwide. More than a half of all trials (51%) are focused on treatment of degenerative eye diseases and malignancies, enrolling nearly 2/3 of all participants in hPSC-based trials. Although no serious adverse event resulting in death or morbidity due to hPSC-based cellular therapy received have been reported, information about safety and clinical efficacy are still very limited.
With the availability of novel technologies for precise genome editing, a new trend in the development of hPSC-based cellular therapies seems to be emerging. Engineering universal donor hPSC lines has become a holy grail in the field. Indeed, because of its effectiveness and simplicity nanomedicine and in vivo delivery of gene therapy could become more advantageous than cellular therapies for treatment of multiple diseases.
In future, for the best outcome, hPSC-based cellular therapy might be combined with other technological advancements such as biomimetic epidural electrical stimulation that can restore trunk and leg motor functions after complete spinal injury.