Exosome: A Novel and Safer Therapeutic Refinement of Mesenchymal Stem Cell

Mesenchymal stem cell (MSC) has just been approved as the first “off-the-shelf” stem cell pharmaceutical drug with an anticipation of more approvals following completion of numerous rigorous clinical trials. Despite this progress, the rationale for MSC therapeutic efficacy remains tenuous and is increasingly rationalized on a secretion rather than differentiation mechanism. Recent studies identifying exosome as the secreted agent mediating MSC therapeutic efficacy could potentially reduce a cell-based drug to a safer biologic-based alternative. Here we review the development of MSC exosome as a potential first-in-class therapeutic, and the unique challenges in the manufacture and regulatory oversight of this new class of therapeutics.