For the estimated 30–50% of allogeneic stem cell transplant recipients who develop chronic graft-versus-host disease, existing immunosuppressive regimens often fall short—leaving patients with diminished quality of life and elevated mortality risk for years post-transplant. A comprehensive narrative review now maps the current evidence landscape for cellular therapies targeting this difficult condition, offering a frank assessment of both progress and persistent gaps.

The review, published in Stem Cell Reviews and Reports, evaluates two primary cellular approaches: mesenchymal stromal cells (MSCs) and regulatory T cells (Tregs). MSCs carry the most substantial clinical experience to date, having been deployed across numerous trials for both prevention and treatment of chronic GVHD. Treg-based strategies, by contrast, operate on a more mechanistically coherent rationale—directly restoring peripheral immune tolerance by suppressing alloreactive effector populations. The authors also survey emerging platforms including natural killer cell strategies and engineered Tregs with enhanced specificity. Critical variables examined include graft source (bone marrow versus peripheral blood stem cells), cell manufacturing standards, dosing protocols, and endpoints—all of which vary substantially across existing trials and complicate cross-study interpretation.

This review arrives at an important inflection point for the field. While Treg and MSC therapies have moved well beyond proof-of-concept, the translation gap between mechanistic elegance and reproducible clinical benefit remains conspicuous. A particularly candid finding is the shared inability of current cellular approaches to adequately address tissue fibrosis—the downstream pathological endpoint that most directly governs organ dysfunction and long-term disability in chronic GVHD. The authors identify non-standardized cell products and inconsistent endpoint definitions as major barriers to progress, issues the broader cellular therapy field has grappled with across disease indications. For health-conscious adults with family members navigating post-transplant care, this review signals that while cellular therapies represent a meaningful advance over conventional steroids alone, durable remission remains elusive and the field requires prospective, rigorously designed trials before these approaches become standard of care.