Definition and scope of stem-cell therapy

Summary

Stem-cell therapy is the use of stem cells to treat or prevent diseases or medical conditions. As of 2024, the only stem-cell therapy approved by the U.S. FDA is hematopoietic stem cell transplantation (HSCT), typically using bone marrow or peripheral blood stem cells, and in some cases umbilical cord blood. HSCT has been used for decades (for example, in leukemia and lymphoma) and works by replacing damaged or destroyed hematopoietic stem cells after chemotherapy, while also helping generate immune responses against cancer cells—though it can cause serious complications such as graft-versus-host disease. Beyond established HSCT, other stem-cell approaches are in clinical development or research. Examples include mesenchymal stromal cell (MSC)-based therapies (such as Canada’s conditional approval of Prochymal for steroid-unresponsive acute graft-versus-host disease in children) and cord-blood-derived products approved for certain blood and immune conditions. Research is also exploring stem cells for neurodegenerative diseases (e.g., Parkinson’s disease), diabetes, heart disease, and regenerative applications across multiple tissues, including mechanisms like anti-inflammatory effects, tissue homing and recruitment of supportive cells, remodeling to reduce scarring, inhibition of apoptosis, and differentiation into relevant tissue types. The scope of stem-cell therapy also includes the sources and preparation of stem cells. Many regenerative therapies isolate stem cells from a patient’s bone marrow or adipose tissue, and bone-marrow-derived cells may be expanded in specialized labs to reach therapeutic cell numbers. The field is also shaped by controversies and regulatory concerns, including ethical debates around embryonic stem cells and cloning-related methods, as well as public scrutiny of marketing practices for unproven treatments (including some cord-blood and COVID-19-related claims).

Key Points

• 1

  Stem-cell therapy uses stem cells to treat or prevent disease; as of 2024, the only FDA-approved stem-cell therapy is hematopoietic stem cell transplantation (HSCT).

• 2

  HSCT is widely practiced and works by reintroducing functional hematopoietic stem cells after chemotherapy, but it can cause serious immune complications such as graft-versus-host disease.

• 3

  Research and emerging clinical uses extend beyond HSCT to MSC-based therapies and other regenerative approaches, including neurodegeneration and tissue repair, with effects thought to involve both cell replacement and paracrine/secretome mechanisms.

• 4

  The scope includes multiple stem-cell sources (bone marrow, adipose tissue, umbilical cord blood, and others) and the need for cell processing/expansion, alongside ongoing ethical, regulatory, and marketing controversies.