For EU Healthcare Professionals

ZEMCELPRO is indicated as stem-cell medicine used to treat adults with hematological malignancies (blood cell cancers) who need an allogeneic hematopoietic stem cell transplantation (allo-HSCT) and for whom no other type of suitable donor cells is available. The information on this website is based on the Production Information

Mechanism of Action

Learn about the scientific rationale and biological activity of UM171-expanded cord blood cells.

Cord Blood Expansion

Umbilical cord blood is an established source of hematopoietic stem cells for allogeneic transplantation. However, the limited number of stem and progenitor cells contained within a single cord blood unit may affect hematopoietic recovery following transplantation in adult patients.

ZEMCELPRO® consists of an ex vivo expanded CD34+ cell fraction generated in the presence of the small molecule UM1716, administered together with the unexpanded cell component derived from the same patient-matched cord blood unit.

How Zemcelpro Works After Infusion

Haematopoietic stem/progenitor cells from ZEMCELPRO® migrate to the bone marrow where they divide, mature, and differentiate in all haematological cell lineages. The mature cells are released into the bloodstream, where some circulate and others migrate to tissue sites, partially or fully restoring blood counts and function, including immune function, of blood-borne cells of marrow origin.

Following infusion, the two cell components of ZEMCELPRO® work together in a complementary manner to support hematopoietic recovery and immune reconstitution.

Role of Expanded CD34+ cells (dorocubicel)

The primary mechanism of action of dorocubicel lies in promoting hematopoietic recovery and immune reconstitution through the activity of expanded CD34+ hematopoietic stem cells1, 2, 5.

Role of Unexpanded cells

The unexpanded CD34- cells, consisting primarily of CD3+ T cells, play a complementary role by supporting immune reconstitution and providing graft-versus-leukemia (GVL) effects post-transplantation3, 4.

References

  1. Cohen, Sandra et al. “Comparison of Outcomes after UM171-Expanded Cord Blood and Six Conventional Donor Source Transplants: A Matched Analysis from the EBMT Registry.” Transplantation and cellular therapy vol. 31,12 (2025): 1039.e1-1039.e14. doi:10.1016/j.jtct.2025.08.006
  2. Cohen, Sandra et al. “Improved outcomes of UM171-expanded cord blood transplantation compared with other graft sources: real-world evidence.” Blood advances vol. 7,19 (2023): 5717-5726. doi:10.1182/bloodadvances.2023010599
  3. Dumont-Lagacé, Maude et al. “UM171 Expansion of Cord Blood Improves Donor Availability and HLA Matching For All Patients, Including Minorities.” Transplantation and cellular therapy vol. 28,7 (2022): 410.e1-410.e5. doi:10.1016/j.jtct.2022.03.016
  4. Dumont-Lagacé, Maude et al. “UM171-Expanded Cord Blood Transplants Support Robust T Cell Reconstitution with Low Rates of Severe Infections.” Transplantation and cellular therapy vol. 27,1 (2021): 76.e1-76.e9. doi:10.1016/j.bbmt.2020.09.031
  5. Cohen, Sandra et al. “Hematopoietic stem cell transplantation using single UM171-expanded cord blood: a single-arm, phase 1-2 safety and feasibility study.” The Lancet. Haematology vol. 7,2 (2020): e134-e145. doi:10.1016/S2352-3026(19)30202-9
  6. Fares, Iman et al. “Cord blood expansion. Pyrimidoindole derivatives are agonists of human hematopoietic stem cell self-renewal.” Science (New York, N.Y.) vol. 345,6203 (2014): 1509-12. doi:10.1126/science.1256337