Hematopoietic Stem Cells (HSC)

Hematopoietic stem cells live mainly in bone marrow and produce every cell type found in blood: red blood cells, the several kinds of white blood cells, and platelets. They are tissue-specific, or multipotent, stem cells in the ISSCR taxonomy, meaning their differentiation options are restricted to blood and immune cell lineages rather than the full range available to pluripotent cells [1].

Hematopoietic stem cell transplantation, commonly called a bone marrow transplant, is the oldest stem cell therapy in routine clinical use, with a track record going back to the 1950s and 1960s. It remains the standard curative option for acute and chronic leukemias, certain lymphomas, multiple myeloma, aplastic anemia, and a range of inherited blood and immune disorders [2][3]. In an allogeneic transplant, donor cells attack any remaining cancer cells directly through a graft-versus-tumor effect, which is part of why the procedure can cure blood cancers that chemotherapy alone cannot [3].

HSC transplantation is also the only stem cell category with genuine, multiple full FDA licenses. The FDA's list of approved cellular and gene therapy products includes several cord-blood-derived hematopoietic progenitor cell products: ALLOCORD from SSM Cardinal Glennon Children's Medical Center, CLEVECORD from the Cleveland Cord Blood Center, Ducord from Duke University School of Medicine, and HEMACORD from the New York Blood Center, among others drawn from cord blood banks including the University of Colorado, MD Anderson, LifeSouth, and Bloodworks [4]. These are all sourced from umbilical cord blood rather than adult bone marrow, but they fall under the same hematopoietic stem cell category and share the same regulatory pathway as a licensed biologic.

The regulatory apparatus around HSC transplant continues to evolve. In January 2025 the FDA approved Grafapex (treosulfan), used in combination with fludarabine, as a new conditioning regimen to clear bone marrow before allogeneic HSC transplant in adults and children with acute myeloid leukemia or myelodysplastic syndromes at elevated risk from standard conditioning drugs [5]. More recently, the FDA approved Tregzi, described as the first regulatory T-cell-based immunotherapy designed to improve outcomes after a matched-donor stem cell transplant, reflecting ongoing efforts to reduce complications like graft-versus-host disease rather than replace the transplant itself [6].

Because HSC transplant has the longest track record of any stem cell therapy, it also has the most complete safety picture: known risks include graft-versus-host disease in allogeneic transplants, infection during the period of immune reconstitution, and conditioning-regimen toxicity, all of which are managed through established clinical protocols rather than treated as open questions. This is a meaningfully different risk-benefit profile from the MSC-based products marketed for anti-aging or wellness purposes elsewhere in this section, which lack anything close to this depth of outcome data.

HSC transplantation is not what most people picture when they see 'stem cell therapy' marketed at a longevity or wellness clinic. It requires matched or partially matched donors, intensive conditioning chemotherapy or radiation, and inpatient hospital care, and it is reserved for serious, often life-threatening blood and immune diseases rather than aging or general wellness. Readers evaluating a commercial stem cell offering should not assume that HSC transplant's decades of FDA approval extend to unrelated MSC or exosome products marketed under similar language; see our regulatory pages for how the FDA actually treats each category.