International Society of Cell and Gene Therapy 2025 exosomes signature series: a thematic synthesis for advancing mesenchymal stromal cell-derived extracellular vesicle therapies

At the International Society of Cell and Gene Therapy (ISCT) 2025 Annual Meeting in New Orleans, mesenchymal stromal cell-derived extracellular vesicles (MSC-EVs) received unprecedented attention, reflecting their rapid shift from experimental concept to promising therapeutic candidates. Scientists, clinicians, industry leaders and regulators participated in focused sessions to examine the questions that will determine how, and when, these products can reach patients: What drives their therapeutic effects? How can manufacturing ensure consistent, clinically active preparations? What is required to gain regulatory confidence, and who will fund the journey? Four thematic threads emerged: (i) pinpointing the "active ingredient" in context-specific settings, (ii) aligning manufacturing with critical quality attributes and potency assays, (iii) engaging regulators as early as possible to align on mechanism-driven product definitions and (iv) ensuring sustainable funding, clear market positioning and trial designs that satisfy both regulatory and commercial requirements. This report summarizes these discussions into actionable priorities: define context-specific mechanisms, embed potency assays into early process development and manufacturing protocols, link analytics to clinical relevance and design development programs that unite scientific credibility with regulatory and market viability. The message from the