Preparing older patients with acute myeloid leukemia (AML) for bone marrow transplants with a reduced intensity conditioning regimen appears to be associated with higher rates of disease-free survival compared with more typical treatments usually given to such patients.
The typical prognosis for older AML patients is poor. Even among patients who achieve complete remission through chemotherapy, survival rates remain low due to high risk of relapse. Although blood or bone marrow transplants can be a viable option for younger patients, conventional preparative regimens leading up to the procedure are often too toxic for patients older than 60 years.
This prospective, multicenter, phase II trial sought to determine the feasibility and effectiveness of a uniform reduced intensity conditioning regimen prior to a blood cell transplant in older patients with AML in clinical remission. Two-year disease-free survival was the primary end point, and the researchers hypothesized that the 2-year disease-free survival would exceed 20%.
A total of 123 patients with AML in first clinical remission following chemotherapy, age 60 to 74 years, at 21 centers across the country underwent transplantation. Match-related donors were available for 47% of the patients, and 53% had unrelated donors. All but eight patients (who received fludarabine and busulfan alone) were conditioned with the same regimen containing fludarabine (30 mg/m2/day), busulfan (6.4 mg/kg IV total dose), and antithymocyte globulin (7.5 mg/kg total dose).
One case of primary graft failure was reported. The rates of both acute and chronic graft versus host disease and treatment-related mortality were relatively low. No unexpected toxicities were associated with these transplants. Relapse was the most common cause of death.
“With a reduced intensity regimen leading up to a transplant, the disease free survival rate in older patients reached 39%,” said Steven M. Devine, MD, of The Ohio State University Comprehensive Cancer Center. “These outcomes are better than those achieved using more conventional treatments and warrant additional comparison research and studies focused on preventing relapse in this patient population.”
This study was presented at the 2012 American Society of Hematology annual meeting in Atlanta, Georgia.