Allogeneic stem cell transplantation (infusion of donor stem cells into a patient) is the best-documented curative treatment for select patients with CML at this time. This type of transplant, however, can cause serious or even life-threatening complications and side effects, and it is often not a good option for older patients or for patients who have other health problems. Results for matched sibling and matched unrelated donors are very similar.
The decision to pursue allogeneic transplantation has become more complicated because many patients have very good responses to TKIs. On the one hand, transplantation has a proven curative track record for some CML patients. On the other hand, the TKIs may be able to control the disease for very long periods and preserve quality of life without the serious side effects of transplantation.
A doctor will consider many important factors when deciding if an allogeneic transplantation is the preferred choice of treatment for a patient. These factors include a patient’s age, general health, the phase of CML, poor response to other treatments and availability of a well-matched donor. Transplant is considered for patients who have resistance to at least two types of TKI; for patients whose CML is in accelerated or blast phase; and for patients who are intolerant to all TKIs.
The most important prognostic factor for survival post-transplant is the phase of CML. Approximately 90 percent of patients with chronic phase CML will be disease-free for 5 years. In patients with accelerated phase CML, approximately 40 to 50 percent are disease-free after 5 years, and only 10 to 20 percent of blast phase patients are alive and disease-free after 5 years.