An allogeneic stem cell transplant is a procedure where the stem cells are taken from another individual who is genetically similar or matched to the patient. The donor's cells must match the patient's, just as with a kidney or other organ transplantation.

In many cases, the stem cell donor is related to the recipient, typically a brother or sister. Stem cells from unrelated donors can also be used if there is a match. It may also be possible to use cells from banked cord blood.

High-dose chemotherapy followed by an allogeneic transplant has the potential to possibly provide better long-term control of myeloma (with longer time without disease progression) than autologous transplants. However, it is a risky procedure with a high death rate of 20% to 50% from the procedure itself. As a result, this type of transplant is rarely performed.

A safer type of allogeneic transplant is much more common. This type of transplant is called a mini-allogeneic transplant. It is also called a reduced intensity or non-myeloablative allogeneic transplant. A mini-transplant uses lower doses of chemotherapy prior to transplant. As a result, the rate of death due to the procedure is very low, similar to that of an autologous transplant.

Click here for a brief slideshow overview of the allogeneic transplant process.