Approved stem cell drugs and therapies

The regulatory approval of stem cell-based therapies represents a watershed moment in regenerative medicine, marking the transition from experimental treatments to evidence-based clinical applications. While the field of stem cell therapy has generated considerable research interest over two decades, only a select number of products have successfully navigated the rigorous approval processes required by regulatory agencies such as the FDA and EMA. Understanding these approved therapies provides critical insights into the current therapeutic landscape and establishes benchmarks for future stem cell product development.

The therapeutic potential of mesenchymal stem cells (MSCs) has been particularly compelling due to their immunomodulatory properties, anti-inflammatory effects, and regenerative capabilities.¹ These adult-derived cells avoid many of the ethical concerns associated with embryonic stem cell research while demonstrating significant clinical promise in treating inflammatory and immune-mediated conditions.

FDA-Approved Mesenchymal Stem Cell Therapies

Ryoncil: The First US FDA Approved MSC Therapy

On December 18, 2024, the Food and Drug Administration approved remestemcel-L-rknd (Ryoncil, Mesoblast, Inc.), marking a historic milestone as the first FDA-approved mesenchymal stromal cell (MSC) therapy.² Ryoncil is indicated for the treatment of steroid-refractory acute graft-versus-host disease (SR-aGVHD) in pediatric patients 2 months of age and older.²

Ryoncil contains allogeneic (donor) bone marrow-derived mesenchymal stromal cells isolated from healthy adult human donors.² The therapy addresses a critical unmet medical need, as steroid-refractory acute graft-versus-host disease can have significant, wide-ranging health consequences, including damage to multiple organs, reduced quality of life and risk of death in affected patients.³

Clinical Evidence and Mechanism of Action

Efficacy was evaluated in MSB-GVHD001 (NCT02336230), a multicenter, prospective, single-arm study in 54 pediatric patients with SR-aGVHD after allogeneic hematopoietic stem cell transplantation.² The study focused on patients with Grade B to D SR-aGVHD, specifically excluding Grade B skin-only cases. SR-aGVHD was defined as acute GVHD progressing within 3 days or not improving within 7 consecutive days of methylprednisolone treatment.

The mechanism of action involves MSCs' intrinsic immunomodulatory properties. In pediatric patients, remestemcel-L reduced levels of tumor necrosis factor receptor type I (TNFR1) and suppressor of tumorigenicity 2 (ST2) from baseline by 79% and 75%, respectively. At Day 180 following remestemcel-L therapy, circulating levels of activated T cells were reduced by 64% from baseline.⁴

Dosing and Administration

The recommended dose is 2 X 10⁶ MSC/kg body weight per intravenous infusion given twice a week for 4 consecutive weeks for a total of 8 infusions². Infusions are administered at least 3 days apart, with potential for continued treatment based on response assessment at 28 days after initial administration.

Global Regulatory Context

Beyond the United States, other regulatory agencies have also approved MSC therapies. In January 2025, in China, the National Medical Products Administration (NMPA) granted conditional approval to Ruibosheng (Amimestrocel Injection, PLEB-001), which uses human umbilical cord-derived MSCs and is also approved for the treatment of steroid-refractory aGVHD.⁵ This represents the first MSC therapy approval in China, signaling growing international acceptance of these therapeutic approaches.

Until April 2023, 1120 registered clinical trials had been using MSC therapies worldwide, but there are only 12 MSC therapies that have been approved by regulatory agencies for commercialization.⁶ Nine of these twelve approved products originate from Asia, with the Republic of Korea leading in approved therapies.

Established Stem Cell Treatments

Hematopoietic Stem Cell Transplantation

Hematopoietic (or blood) stem cell transplantation is routinely reviewed and approved by the U.S. Food and Drug Administration (FDA)⁷. This established therapy is used to treat patients with cancers and disorders affecting the blood and immune system.

Mesenchymal Stem Cell Late-Stage Clinical Trials and Pipeline Developments

While fully approved therapies remain limited, several MSC-based treatments are advancing through late-stage clinical development, suggesting potential future approvals.

Phase III MSC Trials

In February 2025, BioRestorative Therapies' BRTX-100, an autologous mesenchymal stem cell (MSC) therapy, has been granted FDA Fast Track designation for the treatment of chronic lumbar disc disease.⁸ Fast Track designation facilitates development and expedites review of therapies addressing unmet medical needs.

Several Phase III trials are investigating MSC applications in cardiovascular diseases, with studies such as the DREAM-HF trial examining mesenchymal precursor cells in chronic heart failure.⁹ These large-scale trials represent critical steps toward establishing MSC efficacy in major disease areas.

Emerging Applications

A search using the keyword "mesenchymal stem/stromal cell" on ClinicalTrials.gov revealed more than 1600 related clinical trials, with more than 1500 clinical trials employing MSCs as a therapeutic intervention.¹⁰ These clinical trials are mostly in phase I, phase II, or combined phase I/II trials. Only a small percentage of trials are in phase III.¹⁰

Recent trials have explored MSC applications in Alzheimer's disease, with a randomized, double-blind, placebo-controlled, parallel-group phase 2a clinical trial testing laromestrocel, a bone-marrow-derived, allogeneic mesenchymal stem-cell therapy, showing safety and potential efficacy in slowing cognitive decline.¹¹

Regulatory Pathways and Designations

Remestemcel-L-rknd has fast track, orphan drug and priority review designations.² These regulatory pathways reflect the FDA's commitment to accelerating development of therapies for serious conditions with limited treatment options. The multiple designations underscore both the unmet medical need and the therapy's potential clinical significance.

Conclusion

The approval of Ryoncil represents a transformative moment for the mesenchymal stem cell field, validating decades of research and establishing a regulatory precedent for future MSC therapies. While the number of fully approved MSC treatments remains limited, the robust clinical trial pipeline suggests broader therapeutic applications may emerge in the coming years. The success of bone marrow-derived MSCs in treating steroid-refractory acute GVHD demonstrates the therapeutic potential of these adult-derived cells while highlighting the importance of rigorous clinical development and regulatory oversight.

The FDA approval of the first MSC therapy provides US healthcare professionals with an evidence-based treatment option for a devastating pediatric condition while establishing a framework for evaluating future MSC-based interventions. As the field continues to mature, the focus remains on developing safe, effective, and well-characterized MSC products that can address significant unmet medical needs across multiple therapeutic areas.